Post on 13-Mar-2018
MTIB14TC2004R1
STAGE: PUBLIC COMMENT (40.20) DATE: 7 SEPTEMBER 2015 – 6 NOVEMBER 2015
Code of practice for structural timber – Part 2: permissible stress design of solid timber (First revision)
ICS: 91.080.20 Descriptors: member, compression member, tension member, built-up beam, spaced column
DRAFT MALAYSIAN STANDARD
© Copyright 2015
DEPARTMENT OF STANDARDS MALAYSIA
© STANDARDS MALAYSIA 2015 - All rights reserved ii
CONTENTS
Page
Committee representation............................................................................……………… … iv Foreword……...............................................................................................……………… … v 1 Scope………………………………………………………………………………………….. 1
2 Referenced documents……………………………………………………………….......... 1
3 Terms and definition…………………………………………………………………………. 2
4 Timber specification………………………………………………………………………….. 2
5 Species……………………………………………………………………………………….... 2
6 Dimensions and geometrical properties……………………………………………………. 2
7 Grades………………………………………………………………………………………….. 3
8 Grade stresses for individual species and strength group …………………………....... 3
9 Permissible stresses…………………………………………………………………………. 20
10 Duration of loading…………………………………………………………………………... 20
11 Load-sharing systems………………………………………………………………………. 21
12 Flexural members…………………………………………………………………………... 22
13 Compression members…………………………………………………………………….. 28
14 Tension members…………………………………………………………………………… 33
Table 1 Wet grade stresses of timber (N/mm2) moisture content 19 %…………………… 5
Table 2 Dry grade stresses of timber (N/mm2) moisture content 19 %…………………… 11
Table 3 Strength groups of timber…………………………………………………………………. 17 Table 4 Wet and dry grade stresses for various strength groups of timber (stresses and moduli expressed in N/mm
2)…………………………………………….. 19
Table 5 Modification factor K1 for duration of loading…………………………………………. 20
MTIB14TC2004R1
© STANDARDS MALAYSIA 2015 - All rights reserved iii
Table 6 Modification factor K3 for bearing stress……………………………………………….. 23
CONTENTS (continued)
Page
Table 7 Maximum depth to breadth ratios (solid and laminated members)…………….. 26 Table 8 Modification factor K7 used to modify the minimum modulus of elasticity for trimmer joints and lintels…………………………………………………………….. 27 Table 9 Effective length of compression members……………………………………….. 28
Table 10 Modification factor K8 for compression members………………………………. 30 Table 11 Modification factor K9 for the effective length of spaced columns…………… 32
Table A1 Common commercial timber sizes ………………………………………………... 41
Table A2a Geometrical properties of sawn timber at wet condition……………………… 42
Table A2b Geometrical properties of sawn timber at 19 % moisture content……………. 44
Figure 1 Position of end bearing………………………………………………………………. 22
Figure 2 Notched beams……………………………………………………………………….. 24
Figure 3 Axes in spaced columns……………………………………………………………… 32
Annex A Sizes and geometrical properties of Malaysian structural timbers……………… 41 Annex B Modification factor for compression members…………………………………….. 46 Bibliography………………………………………………………………………………………. 47.
© STANDARDS MALAYSIA 2015 - All rights reserved iv
Committee representation The Industry Standards Committee on Timber, Timber Products and Timber Structures, under whose authority this Malaysian Standard was developed, comprises representatives from the following organisations: Construction Industry Development Board Malaysia Forest Research Institute of Malaysia Department of Standards Malaysia Institution of Engineers Malaysia Jabatan Kerajaan Tempatan Malaysian Furniture Promotion Council Malaysian Panel-Products Manufacturer’s Association Malaysian Public Works Department Malaysian Timber Council Malaysian Timber Industry Board (Secretariat) Malaysian Wood Industries Association Malaysian Wood Moulding and Joinery Council Malaysian Wood Preserving Association Sabah Timber Industries Association Sarawak Timber Association Sarawak Timber Industry Development Corporation Timber Exporters Association of Malaysia Universiti Putra Malaysia UniversitiTeknologi MARA The Technical Committee on Timber Structures which supervised the development of this Malaysian Standard consists of representatives from the following organisations: Construction Industry Development Board Malaysia Forest Research Institute Malaysia Institute of Engineers Malaysia Malaysian Institute of Architects Malaysian Timber Council Malaysian Timber Industry Board (Secretariat) Ministry of Urban Wellbeing, Housing & Local Government Multinail Asia Sdn Bhd Public Works Department Sarawak Timber Industry Development Corporation Timber Exporters’ Association of Malaysia Universiti Putra Malaysia Universiti Sains Malaysia Universiti Teknologi Malaysia Universiti Teknologi Mara Universiti Tun Hussein Onn Malaysia Wood Industry Skills Development Centre The Working Group on Structural Use of Timber Part 11 which developed this Malaysian Standard consists of representatives from the following organisations: Forest Research Institute Malaysia Malaysian Timber Industry Board (Secretariat) Multinail Asia Sdn Bhd Public Works Department Sarawak Timber Industry Development Corporation Universiti Sains Malaysia Universiti Teknologi Malaysia Universiti Teknologi MARA Universiti Tun Hussein Onn Malaysia
MTIB14TC2004R1
© STANDARDS MALAYSIA 2015 - All rights reserved v
FOREWORD
This Malaysian Standard was developed by the Working Group on MS 544 Part 1 under the authority of the Timber, Timber Products and Timber Structures Industry Standard Committee. This Malaysian Standard is the first revision of MS 544 - 2, Code of practice for structural use of timber – Part 2: Permissible stress design of solid timber. Major modifications in this revision are as follows: a) The scope has been modified; b) Annex A and B has been modified; and c) The structure of MS has been modified MS 544 consists of the following parts and sections, under the general title Code of practice for structural use of timber: Part 1: General Part 2: Permissible stress design of solid timber Part 3: Permissible stress design of glued laminated timber Part 4: Timber panel products Part 4 is further divided into a number of sections as follows: Section 1: Structural plywood Section 2: Marine plywood Section 3: Cement bonded particleboard Section 4: Oriented strand board Part 5: Timber joints Part 6: Workmanship, inspection and maintenance Part 7: Testing Part 8: Design, fabrication and installation of prefabricated timber for roof trusses Part 9: Fire resistance of timber structures Part 9 is further subdivided into a number of sections as follows: Section 1: Method of calculating fire resistance of timber members
© STANDARDS MALAYSIA 2015 - All rights reserved vi
FOREWORD (Continued) Part 10: Preservative treatment of structural timbers Part 11: Recommendation for the calculation basis for span tables Part 11 is further divided into a number of sections as follows: Section 1: Domestic floor joists Section 2: Ceiling joists Section 3: Ceiling binders Section 4: Domestic rafters Part 12: Laminated veneer lumber for structural application This Malaysian Standard cancels and replaces MS 544-2: 2001. Compliance with a Malaysian Standard does not of itself confer immunity from legal obligations.
© STANDARDS MALAYSIA 2015 - All rights reserved 1
Code of practice for structural use of timber - Part 2: Permissible stress design of solid timber (First revision)
1 Scope
This Part gives recommendations for the structural use of the Malaysian hardwood and
softwood timber species in load bearing members. It includes recommendations on quality,
grade stresses and modification factors applicable to these timbers when used as simple
members, or as parts of built-up components, or as parts of structures incorporating other
materials. It does not, and it is not intended to deal comprehensively with all aspects of timber
construction. In particular it does not cover well tried and traditional methods of timber
construction which have been employed successfully over a long period of time.
2 References documents The following referenced normative references are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the normative reference (including any amendments) applies.
MS 544 – 1, Code of practice for structural use of timber - Part 1: General
MS 544 – 3, Code of practice for structural use of timber - Part 3: Permissible stress design
of glued laminated timber
MS 544 – 5, Code of practice for structural use of timber - Part 5: Timber joints
MS 1714: 2003, Specification for Visual Strength Grading Of Tropical Hardwood Timber
BS 5268-2:1996, Structural use of timber - Part 2: Code of practice for permissible
stress design, materials and workmanship
MS 1553: 2002, Code of Practice on Wind Loading For Building Structure
MS 837: 2006, Solid Timber - Determination of Moisture Content (First Revision)
MS 360: 2006, Treatment of Timber with Copper/Chrome/Arsenic (CCA) Wood Preservatives – Specification (Third Revision)
2 © STANDARDS MALAYSIA 2015 - All rights reserved
3 Terms and definitions For the purposes of this Standard, the terms and definitions given in BS 6100-0:2010 and MS 544-1 apply.
4. Timber specification Specifiers should consider and, where necessary, specify requirements under each of the
following headings. All relevant standards should be referenced.
a) Strength group, grade and species (see MS 544 Part 1, Clause 5)
b) Sizes and surface condition (see MS 544 Part 1 Sub-clause 6.8, see MS 544 Part 2
Clause 6).
c) Service class or moisture content. (see MS 544 Part 1 Sub-clause 6.4).
d) Durability (see MS 837: 2006: Solid Timber - Determination Of Moisture Content
(First Revision)
e) Preservation and preservatives of timber.(see MS 360:2006)
f) Special requirements. These may include more restrictive grade, requirements for
distortion, wane and marking and preservation treatment (see MS 1714:2003:
Specification for Visual Strength Grading of Tropical Hardwood Timber).
5 Species Many factors are involved in the choice of species but from the purely structural view, it is the grade stresses which are of prime importance. These differ for each species and grade. To provide an alternative method of specification for the designer and specifiers and greater flexibility of supply, MS 544: Part 2 gives a series of strength groups which for design use can be considered as being independent of species. Grade stresses for individual species are given in Tables 1 and 2, and strength groups (SG) are given in Table 4. The list of species under each strength group is given in Table 3. For some applications it may be necessary to specify particular species from within a strength group to take into account of particular characteristics, e.g. natural durability, amenability to preservatives, glues and fasteners. NOTE. Example for preservatives see MS 360:2006: Treatment of Timber with Copper / Chrome / Arsenic (CCA) Wood Preservatives – Specification (Third Revision),
6 Dimensions and geometrical properties Timber structures can be designed using any size of timber. For design purposes, the
effective cross-section and geometrical properties of a structural member should be
calculated using the target size. Some common commercial timber sizes are given in Annex
A, Table A1 and geometrical properties are given in Table A2 and A3.
It is essential to include the required target dimensions of members in specifications and drawings.
© STANDARDS MALAYSIA 2015 - All rights reserved 3
For timber specified in accordance with Appendix A, the design should be based on its target size (minimum size). No modifications need to be made to the geometrical properties which change size with moisture content.
7 Grades All timbers used for structural work should be stress graded in accordance with MS 1714: 2003.
8 Grade stresses for individual species and strength group 8.1 General Grade stresses for wet and dry conditions are given in Tables 1 and 2, respectively for individual species and Table 4 for each strength groups and grades. As it is difficult to artificially dry timber more than 100 mm thick, the wet stresses and moduli should normally be used for solid timber members more than 100 mm thick, unless they are specially dried. Design may be based either on the grade stresses for the strength group or on those for the individual species and grades. 8.2 Clear wood stresses in timber The clear wood stresses applicable to some structural timber are given in Tables 1 and 2. These are governed by the general characteristics of the particular species, free from all visible defects and are related to the strength of the timber in wet and dry conditions respectively. In the derivation of clear wood stresses, the following factors have been considered: a) moisture content; b) variability; and c) factors of safety (which includes duration of loading, size and shape of member,
accidental overloading, errors in design assumptions, etc.) 8.3 Grade stresses in sawn timber Grade stresses are related to clear wood stresses of the individual species (see Clause 7.2) and governed by the effect of visible gross features such as knots, sloping grain etc. (see MS 1714:2003) The reduction in strength due to a defect is expressed in terms of the strength ratio which may be defined as the ratio of the strength of a piece of timber with a defect to the strength of the same piece without a defect. Strength ratios used in reducing the clear wood stresses to the grade stresses are related to the particular grade and are also governed by the defects which influence the particular strength property.
4 © STANDARDS MALAYSIA 2015 - All rights reserved
It should be noted that the intrinsic material cost rises with the grade, whilst general availability is reduced. At the design stage, reference should be made to commercial sources for information on the availability of particular species, grades quantities and dimensions. The stresses of different grades of timber species are given in Tables 1 and 2. 8.4 Strength groups of timbers Timbers having similar strength and stiffness properties have been grouped together for simplicity in design procedure (see Table 4). The groups thus formed are necessarily based on the weakest species in the particular group. To overcome possible shortages of certain timber species in different regions of Malaysia it is recommended that designs be based on strength groups and that designers specify structural timber requirements in terms of strength groups. Where designers wish to take full advantage of the strength of particular species, and where commercial supplies are known to exist, a particular timber species may be specified, and the grade quoted for individual species may be used.
20 © STANDARDS MALAYSIA 2015 - All rights reserved
Table 1. Wet grade stresses of timber (N/mm2)
moisture content 19 %
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain1)
Shear
parallel to grain
Modulus of elasticity
for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
1 Agoho 22.9 18.1 14.3 13.8 10.8 8.6 20.3 16.0 12.7 4.82 4.10 3.86 3.61 1.99 1.55 1.25 14900 9800
2 Alan bunga3)
13.8 10.9 8.6 8.3 6.5 5.2 12.4 9.8 7.7 1.29 1.10 1.03 0.97 1.61 1.25 1.01 12000 8100
3 Ara 6.9 5.4 4.33)
4.1 3.2 2.6 7.7 6.0 4.8 1.03 0.87 0.82 0.77 1.02 0.79 0.63 6200 42003)
4 Babai 12.5 9.8 7.83)
7.5 5.9 4.73)
10.7 8.4 6.7 1.86 1.58 1.49 1.40 1.68 1.31 1.05 10600 7100
5 Balau 30.3 23.9 18.9 18.2 14.3 11.3 26.8 21.1 16.8 4.59 3.90 3.67 3.44 2.67 2.08 1.67 18400 13500
6 Balau, red 18.1 14.2 11.3 10.9 8.5 6.8 15.3 12.0 9.5 2.38 2.02 1.90 1.78 2.07 1.61 1.30 13700 9800
7 Balek angin bopeng
10.8 8.5 6.7 6.5 5.1 4.0 14.7 11.6 9.2 2.59 2.20 2.07 1.94 2.18 1.70 1.36 13200 10100
8 Batai 8.7 6.8 5.4 5.2 4.1 3.2 6.1 4.8 3.8 0.62 0.53 0.50 0.46 0.91 0.71 0.57 6800 4400
9 Bayur 12.2 9.6 7.6 7.3 5.8 4.6 8.5 6.7 5.3 1.64 1.39 1.31 1.23 1.19 0.92 0.74 7500 5700
10 Bekak 20.8 16.4 13.0 12.5 9.8 7.8 17.2 13.5 10.7 3.20 2.72 2.56 2.403)
2.89 2.25 1.80 15300 12200
11 Belian3)
29.0 22.8 18.1 17.4 13.7 10.9 28.6 22.6 17.9 5.43 4.62 4.34 4.07 2.75 2.14 1.72 18000 12100
12 Berangan 14.3 11.3 8.9 8.5 6.7 5.4 13.8 10.8 8.6 3.03 2.57 2.42 2.27 1.53 1.19 0.96 12000 10300
13 Bintangor 11.7 9.2 7.3 7.0 5.5 4.4 10.6 8.4 6.6 1.52 1.29 1.22 1.14 1.61 1.25 1.01 12100 8300
14 Bitis 30.0 23.6 18.8 18.0 14.2 11.3 32.3 25.5 20.2 5.53 4.70 4.42 4.15 2.54 1.98 1.59 21900 18400
15 Brazil nut 18.1 14.2 11.3 10.8 8.5 6.8 11.7 9.2 7.3 3.01 2.56 2.41 2.26 2.48 1.93 1.55 10100 8900
16 Chengal 31.6 24.9 19.7 19.0 14.9 11.8 30.2 23.8 18.9 5.85 4.97 4.68 4.39 3.13 2.44 1.96 18100 13300
17 Damar Minyak 9.6 7.6 6.0 5.8 4.6 3.6 8.2 6.5 5.2 1.08 0.92 0.86 0.813)
1.47 1.14 0.92 10500 6700
Table 1. Wet grade stresses of timber (N/mm2)
moisture content 19 % (continued)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain
1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
18 Dedali 14.2 11.2 8.8 8.5 6.7 5.3 12.2 9.6 7.7 2.26 1.92 1.81 1.69 1.53 1.19 0.96 10700 7400
19 Dedaru 28.6 22.5 17.9 17.2 13.5 10.7 23.7 18.7 14.9 3.50 2.97 2.80 2.62 2.67 2.08 1.67 17300 12600
20 Delek 21.5 16.9 13.4 12.9 10.1 8.0 16.2 12.7 10.1 3.95 3.36 3.16 2.96 2.10 1.63 1.31 16900 10500
21 Derum 15.4 12.1 19.6 9.2 7.3 5.8 14.3 11.3 8.9 2.54 2.16 2.03 1.903)
2.68 2.08 1.67 12500 9500
22 Durian 13.1 10.3 8.2 7.9 6.2 4.9 11.4 8.9 7.1 1.41 1.20 1.13 1.06 1.43 1.11 0.89 8600 6600
23 Geronggang 9.5 7.5 5.9 5.7 4.5 3.5 6.6 5.2 4.1 0.94 0.80 0.75 0.70 1.09 0.85 0.68 8000 6300
24 Gerutu 16.3 12.9 10.2 9.8 7.7 6.1 15.6 12.3 9.7 1.69 1.44 1.35 1.27 1.33 1.04 0.83 13200 10000
© STANDARDS MALAYSIA 2015 - All rights reserved 21
25 Giam 26.0 20.5 16.3 15.6 12.3 9.8 21.9 17.3 13.7 5.33 4.53 4.26 4.00 3.26 2.54 2.04 14600 8700
26 Jelutong 9.4 7.4 5.9 5.6 4.4 3.5 8.0 6.3 5.0 1.02 0.87 0.82 0.763)
1.23 0.96 0.77 7900 5400
27 Jenitri 10.1 7.9 6.2 6.0 4.7 3.8 7.8 6.2 4.9 1.02 0.87 0.82 0.76 1.26 0.98 0.79 9100 6500
28 Jongkong 11.3 8.9 7.0 6.8 5.3 4.2 9.4 7.4 5.9 1.02 0.87 0.82 0.763)
1.44 1.12 0.90 9300 6200
29 Kapur 19.2 15.1 12.0 11.5 9.1 7.2 17.2 13.5 10.8 2.70 2.30 2.16 2.03 1.71 1.33 1.07 13200 9500
30 Kasah 10.0 7.9 6.2 6.0 4.7 3.7 9.1 7.2 5.7 1.53 1.30 1.22 1.15 1.71 1.33 1.07 9200 5500
31 Kasai 14.9 11.7 9.33)
8.9 7.0 5.63)
12.6 9.9 7.8 2.40 2.04 1.92 1.80 2.00 1.56 1.25 12400 8300
32 KayuKundur 13.9 11.0 8.7 8.4 6.6 5.2 12.3 9.6 7.7 2.37 2.01 1.90 1.78 1.86 1.44 1.16 12600 7700
33 Kedondong 13.3 10.5 8.3 8.0 6.3 5.0 11.4 8.9 7.1 1.50 1.28 1.20 1.13 1.38 1.07 0.86 11200 8200
34 Kekatong 26.4 20.8 16.5 15.8 12.5 9.9 22.3 17.6 13.9 4.46 3.79 3.57 3.34 2.76 2.15 1.73 17000 11700
22 © STANDARDS MALAYSIA 2015 - All rights reserved
Table 1. Wet grade stresses of timber (N/mm2)
moisture content 19 % (continued)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain
1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
35 Kelat 20.1 15.8 12.53)
12.1 9.5 7.53)
19.7 15.5 12.3 2.41 2.05 1.93 1.81 2.17 1.68 1.35 16400 10200
36 Keledang 14.4 11.3 9.0 8.6 6.8 5.4 11.4 8.9 7.1 2.00 1.70 1.60 1.503)
1.71 1.33 1.07 11600 7000
37 Kembangsemangkok 20.9 16.5 13.1 12.5 9.9 7.9 17.8 14.0 11.1 2.38 2.02 1.90 1.783)
1.84 1.43 1.15 15500 12900
38 Kempas 20.7 16.3 13.0 12.4 9.8 7.8 22.3 17.6 13.9 3.73 3.17 3.00 2.80 2.24 1.74 1.40 16600 13100
39 Keranji 23.5 18.5 14.7 14.1 11.1 8.8 18.6 14.6 11.6 3.60 3.06 2.88 2.703)
1.84 1.43 1.15 18800 13900
40 Keruing 12.3 9.7 7.7 7.4 5.8 4.6 10.2 8.0 6.4 1.97 1.67 1.58 1.48 1.36 1.06 0.85 10200 6400
41 Keruntum 17.2 13.5 10.7 10.3 8.1 6.4 16.1 12.7 10.0 2.71 2.30 2.17 2.033)
1.99 1.55 1.24 14400 10200
42 Ketapang 14.6 11.5 9.1 8.8 6.9 5.5 9.6 7.6 6.0 1.53 1.30 1.22 1.15 1.71 1.33 1.07 9700 8500
43 Kulim 20.2 15.9 12.6 12.1 9.5 7.6 19.1 15.0 11.9 2.55 2.17 2.04 1.91 2.15 1.67 1.35 13300 10200
44 Kungkur 16.7 13.2 10.5 10.0 7.9 6.3 12.8 10.1 8.0 2.00 1.70 1.60 1.503)
1.84 1.43 1.15 10400 7200
45 Laran 8.8 6.9 5.5 5.3 4.1 3.3 7.6 6.0 4.7 0.95 0.81 0.76 0.713)
1.22 0.95 0.76 7300 4200
46 Machang 11.0 8.7 6.9 6.6 5.2 4.1 9.3 7.3 5.8 2.24 1.90 1.79 1.68 1.71 1.33 1.07 6700 5800
47 Malabera 17.4 13.7 10.8 10.4 8.2 6.5 13.7 10.8 8.5 3.26 2.77 2.61 2.44 1.55 1.20 0.97 12800 9800
48 Mata ulat 27.9 22.0 17.4 16.7 13.2 10.4 23.6 18.6 14.8 4.58 3.89 3.66 3.43 2.67 2.08 1.67 16300 14900
49 Medang 13.7 10.8 8.6 8.2 6.5 5.2 11.6 9.1 7.2 1.21 1.03 0.97 0.91 1.50 1.17 0.94 7900 7700
50 Melantai/Kawang 10.6 8.4 6.6 6.4 5.0 4.0 8.7 6.9 5.4 1.20 1.02 0.96 0.90 1.17 0.91 0.73 10800 6200
51 Melunak 12.8 10.1 8.0 7.7 6.1 4.8 13.7 10.8 8.6 1.92 1.63 1.54 1.44 1.49 1.16 0.93 10600 7000
© STANDARDS MALAYSIA 2015 - All rights reserved 23
Table 1. Wet grade stresses of timber (N/mm2)
moisture content 19 % (continued)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain
1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
52 Mempening 16.5 13.0 10.3 9.9 7.8 6.2 14.2 11.2 8.9 3.39 2.88 2.71 2.543)
2.24 1.74 1.40 16300 10600
53 Mempisang 13.0 10.2 8.1 7.8 6.1 4.9 10.2 8.1 6.4 1.25 1.06 1.00 0.94 1.49 1.16 0.93 12100 7300
54 Mengkulang 15.5 12.2 9.7 9.3 7.3 5.8 11.3 8.9 7.1 2.03 1.72 1.62 1.52 1.86
1.45 1.17 10600 6500
55 Meransi 21.2 16.7 13.2 12.7 10.0 7.9 17.0 13.3 10.6 3.95 3.36 3.16 2.96 2.53 1.96 1.58 12400 10000
56 Meranti bakau 16.1 12.7 10.0 9.7 7.6 6.0 12.4 9.8 7.7 1.83 1.55 1.46 1.37 1.63 1.27 1.02 14700 11000
57 Meranti, dark red 14.1 11.1 8.8 8.5 6.7 5.3 11.4 9.0 7.1 1.12 0.95 0.90 0.84 1.50 1.16 0.94 10100 9000
58 Meranti, light red 10.8 8.5 6.7 6.5 5.1 4.0 9.6 7.6 6.0 1.10 0.93 0.88 0.82 1.05 0.82 0.66 9300 6900
59 Meranti, white 14.8 11.7 9.2 8.9 7.0 5.5 13.4 10.6 8.4 1.28 1.09 1.02 0.96 1.21 0.95 0.76 10800 6100
60 Meranti, yellow 11.7 9.2 7.3 7.0 5.5 4.4 10.0 7.9 6.2 1.55 1.32 1.24 1.16 1.07 0.83 0.67 10500 7900
61 Merawan 22.9 18.0 14.3 13.7 10.8 8.6 20.3 16.0 12.7 2.72 2.31 2.18 2.04 1.74 1.35 1.093)
15000 10600
62 Merbatu 24.2 19.0 15.1 14.5 11.4 9.1 18.8 14.8 11.7 3.50 2.97 2.80 2.623)
2.32 1.80 1.45 18100 12900
63 Merbau 21.1 16.6 13.2 12.7 10.0 7.9 15.7 12.3 9.8 3.23 2.74 2.58 2.42 2.35 1.83 1.47 13900 8600
64 Merpauh 15.7 12.4 9.8 9.4 7.4 5.9 14.4 11.3 9.0 2.35 2.00 1.88 1.76 2.13 1.66 1.33 14200 9600
65 Mersawa 12.6 10.0 7.9 7.6 6.0 4.7 10.2 8.0 6.4 2.26 1.92 1.81 1.69 1.55 1.21 0.97 9200 4900
66 Mertas 24.8 19.5 15.5 14.9 11.7 9.3 20.1 15.9 12.5 3.50 2.97 2.80 2.623)
2.38 1.85
1.49 15700 12500
67 Nyalin 18.2 14.4 11.4 10.9 8.6 6.8 15.0 11.8 9.4 3.53 3.00 2.82 2.65 2.66 2.07 1.66 13000 8600
68 Nyatoh 13.7 10.8 8.6 8.2 6.5 5.2 11.8 9.3 7.4 1.99 1.69 1.59 1.49 1.73 1.35 1.08 10600 8200
24 © STANDARDS MALAYSIA 2015 - All rights reserved
Table 1. Wet grade stresses of timber (N/mm2)
moisture content 19 % (continued)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain
1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
69 Pauh kijang 22.2 17.5 13.93)
13.3 10.5 8.33)
25.1 19.8 15.7 2.60 2.21 2.08 1.953)
2.78 2.16 1.74 17200 11600
70 Pelajau 8.2 6.5 5.1 4.9 3.9 3.1 9.3 7.3 5.8 0.68 0.58 0.54 0.51 0.91 0.71 0.57 8600 4100
71 Penaga 29.2 23.0 18.2 17.5 13.8 10.9 28.9 22.8 18.1 6.68 5.68 5.34 5.01 3.42 2.66 2.14 17000 14300
72 Penarahan 12.6 9.9 7.9 7.6 5.9 4.7 11.2 8.8 7.0 2.842 2.41 2.27 1.423)
1.45 1.13 0.90 9400 7600
73 Penyau3)
23.4 18.4 14.6 14.0 11.0 8.8 25.2 19.8 15.7 6.05 5.14 4.84 4.54 2.21 1.72 1.38 17600 11800
74 Perah 19.7 15.5 12.33)
11.8 9.3 7.4 24.8 19.5 15.7 2.73 2.32 2.18 2.05 3.04 2.37 1.90 14800 10000
75 Perupok 17.5 13.8 10.9 10.5 8.3 6.5 13.8
10.8 8.6 2.00 1.70 1.60 1.50 1.54 1.19 0.96 11300 7700
76 Petai 11.0 8.7 6.9 6.6 5.2 4.1 9.1 7.2 5.7
1.35 1.15 1.08 1.01 1.37 1.07 0.86 9600 6700
77 Petaling 19.0 15.0 11.93)
11.4 9.0 7.13)
19.3 15.2 12.0 2.59 2.20 2.07 1.94 2.38 1.85 1.48 15000 101003)
78 Pulai 7.2 5.6 4.5 4.3 3.4 2.7 5.3 4.2 3.3 0.83 0.70 0.66 0.623)
1.07 0.83 0.67 6200 3400
79 Punah 19.3 15.2 12.1 11.6 9.1 7.3 15.0 11.8 9.4 2.64 2.24 2.11 1.98 2.24 1.74 1.40 13500 11700
80 Ramin 14.2 11.2 8.9 8.5 6.7 5.3 12.4 9.8 7.8 1.87 1.59 1.50 1.403)
1.49 1.16 0.93 14200 11000
81 Ranggu 20.8 16.4 13.0 12.5 9.8 7.8 19.4 15.3 12.1 3.34 2.84 2.67 2.50 2.39 1.86 1.49 15300 10700
82 Rengas 18.8 14.8 11.8 11.3 8.9 7.1 12.1 9.5 7.6 2.63 2.23 2.10 1.97 2.48 1.93 1.55 14000 11000
83 Resak 21.1 16.6 13.2 12.7 10.0 7.9 15.0 11.8 9.3 2.92 2.48 2.34 2.19 1.80 1.40 1.12 14400 8500
84 Rubberwood 12.6 9.9 7.9 7.6 5.9 4.7 9.1 7.2 5.7 2.21 1.88 1.77 1.66 2.20 1.71 1.38 8800 6200
85 Sengkuang3)
17.0 13.4 10.6 10.2 8.0 6.4 15.2 12.0 9.5 2.26 1.92 1.81 1.69 1.91 1.49 1.20 10400 7000
© STANDARDS MALAYSIA 2015 - All rights reserved 25
Table 1. Wet grade stresses of timber (N/mm2)
moisture content 19 % (concluded)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain
1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
86 Sepetir 11.0 8.6 6.8 6.6 5.2 4.1 9.4 7.4 5.9 1.92 1.63 1.54 1.44 1.92 1.49 1.20 11700 6800
87 Sesendok 10.8 8.6 6.8 6.5 5.2 4.1 9.1 7.2 5.7 0.99 0.84 0.79 0.74 1.28 1.00 0.80 8500 7100
88 Simpoh 16.5 13.0 10.3 9.9 7.8 6.2 18.2 14.3 11.4 2.87 2.44 2.30 2.15 1.61 1.25 1.01 14300 9400
89 Surian batu 21.0 16.5 13.1 12.6 9.9 7.9 16.7 13.2 10.4 5.06 4.30 4.05 3.79 2.77 2.16 1.73 12400 10800
90 Teak 16.2 12.8 10.1 9.7 7.7 6.1 12.8 10.1 8.0 2.99 2.54 2.39 2.24 2.56 1.99 1.60 9400 6100
91 Tembusu 14.2 11.2 8.9 8.5 6.7 5.3 14.8 11.7 9.3 3.20 2.72 2.56 2.403)
1.68 1.30 1.05 12600 6300
92 Terap 10.2 8.1 6.4 6.1 4.9 3.8 7.9 6.2 5.0 1.37 1.16 1.10 1.03 1.30 1.01 0.81 9900 5400
93 Terentang 6.6 5.2 4.2 4.0 3.1 2.5 5.3 4.2 3.3 0.62 0.53 0.50 0.46 0.99 0.77 0.62 5700 3000
94 Tualang 22.4 17.6 14.0 13.4 10.6 8.4 18.2 14.3 11.4 3.67 3.12 2.94 2.75 2.30 1.79 1.44 16400 10800
1) When there is no wane at the bearing area, the basic stress figures may be used for all grades.
2) Sel, Std and Com stand for select structural, standard structural and common building grades respectively as defined in the MS 1714:2003.
3) Figures are estimated due to data not fully available but can be safely used in design.
Table 2. Dry grade stresses of timber (N/mm2)
moisture content 19 %
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
1 Agoho 27.1 21.4 17.0 16.3 12.8 10.2 23.3 18.3 14.5 6.00 5.10 4.80 4.50 4.43 3.44 2.77 16000 10400
2 Alan bunga 3)
15.4 12.2 9.6 9.2 7.3 5.8 14.2 11.2 8.9 1.42 1.21 1.14 1.06 1.72 1.34 1.08 12300 8300
3 Ara 8.4 6.6 5.23)
5.0 4.0 3.13)
9.2 7.2 5.7 1.56 1.32 1.25 1.17 1.08 0.84 0.67 6700 45003)
4 Babai 14.7 11.6 9.2 8.8 7.0 5.5 13.1 10.3 8.2 2.13 1.81 1.70 1.60 1.89 1.47 1.18 10800 7200
5 Balau 33.6 26.5 21.0 20.2 15.9 12.6 28.5 22.5 17.8 4.67 3.97 3.74 3.50 2.94 2.28 1.84 19400 14200
6 Balau, red 20.2 15.9 12.6 12.1 9.5 7.6 17.8 14.0 11.1 2.82 2.40 2.26 2.11 2.33 1.81 1.46 14500 10400
7 Balek angin bopeng
15.8 12.5 9.9 9.5 7.5 5.9 19.1 15.0 11.9 3.82 3.25 3.06 2.86 2.81 2.21 1.75 15600 12000
MS
54
4 : P
AR
T 2
: 200
1
26 © STANDARDS MALAYSIA 2015 - All rights reserved
8 Batai 9.7 7.6 6.0 5.8 4.6 3.6 7.0 5.5 4.4 0.77 0.65 0.62 0.58 0.98 0.76 0.61 7300 4800
9 Bayur 13.7 10.8 8.6 8.2 6.5 5.2 10.2 8.1 6.4 1.64 1.39 1.31 1.23 1.19 0.92 0.74 7500 5700
10 Bekak 26.8 21.1 16.7 16.1 12.7 10.0 22.2 17.5 13.9 3.61 3.07 2.89 2.713)
3.26 2.54 2.04 16500 13100
11 Belian 3)
31.1 24.5 19.5 18.7 14.7 11.7 30.0 23.6 18.7 5.83 4.96 4.66 4.37 2.92 2.27 1.83 18800 12600
12 Berangan 16.8 13.2 10.5 10.1 7.9 6.3 16.8 13.2 10.5 3.34 2.84 2.67 2.50 1.68 1.31 1.05 12500 10700
13 Bintangor 15.9 12.5 9.9 9.5 7.5 5.9 14.1 11.2 8.8 1.68 1.43 1.34 1.26 2.13 1.66 1.33 14000 9600
14 Bitis 35.9 28.3 22.5 21.5 17.0 13.5 36.0 28.4 22.5 5.60 4.76 4.48 4.20 2.97 2.31 1.86 23000 19300
15 Brazil nut 19.0 14.9 11.9 11.4 8.9 7.1 12.8 10.1 8.0 3.40 2.89 2.72 2.55 2.64 2.06 1.65 10300 9100
16 Chengal 35.8 28.1 22.3 21.5 16.9 13.4 31.9 25.1 19.9 5.85 4.97 4.68 4.39 3.13 2.44 1.96 19000 14000
17 Damar Minyak 13.1 10.3 8.2 7.9 6.2 4.9 11.4 9.0 7.1 1.35 1.15 1.08 1.01 1.47 1.14 0.92 11700 7500
Table 2. Dry grade stresses of timber (N/mm2)
moisture content 19 % (continued)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
18 Dedali 17.6 13.9 11.0 10.6 8.3 6.6 14.8 11.7 9.3 2.35 2.00 1.88 1.76 1.73 1.34 1.08 11000 7600
19 Dedaru 32.3 25.5 20.2 19.4 15.3 12.1 26.7 21.0 16.7 3.82 3.25 3.05 2.86 3.14 2.48 1.96 18000 13100
20 Delek 22.8 17.9 14.2 13.7 10.7 8.5 18.1 14.2 11.3 4.15 3.53 3.32 3.11 2.23 1.73 1.39 17600 10900
21 Derum 18.2 14.4 11.4 10.9 8.6 6.8 17.7 13.9 11.0 4.37 3.71 3.50 3.283)
3.38 2.63 2.11 14800 11200
22 Durian 15.6 12.3 9.7 9.4 7.4 5.8 13.1 10.3 8.2 1.46 1.24 1.17 1.10 1.58 1.23 0.99 9200 7000
23 Geronggang 11.0 8.6 6.8 6.6 5.2 4.1 7.8 6.1 4.8 1.13 0.96 0.90 0.85 1.23 0.96 0.77 8100 6400
24 Gerutu 18.0 14.2 11.2 10.8 8.5 6.7 17.9 14.1 11.2 1.84 1.56 1.47 1.38 1.47 1.14 0.92 13600 10300
25 Giam 29.7 23.4 18.6 17.8 14.0 11.2 23.3 18.3 14.6 5.89 5.00 4.71 4.42 3.57 2.78 2.23 16000 9500
26 Jelutong 11.3 8.9 7.1 6.8 5.3 4.3 9.2 7.2 5.8 1.28 1.09 1.02 0.96 1.32 1.02 0.82 8000 5500
27 Jenitri 12.3 9.7 7.7 7.4 5.8 4.6 10.1 7.9 6.3 1.28 1.09 1.02 0.96 1.46 1.15 0.91 10000 7200
28 Jongkong 15.0 11.8 9.4 9.0 7.1 5.6 12.3 9.7 7.7 1.36 1.16 1.09 1.023)
0.91 1.48 1.19 10500 7000
29 Kapur 22.0 17.3 13.7 13.2 10.4 8.2 20.4 16.0 12.7 3.00 2.55 2.40 2.25 1.85 1.44 1.16 13700 9800
30 Kasah 11.3 8.9 7.0 6.8 5.3 4.2 9.6 7.6 6.0 1.68 1.43 1.34 1.27 1.76 1.37 1.10 9600 5700
31 Kasai 17.2 13.5 10.73)
10.3 8.1 6.43)
15.6 12.3 9.7 2.90 2.46 2.32 2.17 2.68 2.09 1.68 12800 8600
32 Kayu Kundur 14.6 11.5 9.1 8.8 6.9 5.5 13.5 10.6 8.5 2.68 2.27 2.15 2.01 1.98 1.53 1.23 13000 7900
33 Kedondong 15.8 12.4 9.8 9.5 7.4 5.9 14.5 11.4 9.1 1.74 1.48 1.39 1.30 1.76 1.37 1.10 11900 8700
34 Kekatong 33.4 26.3 20.8 20.0 15.8 12.5 26.3 20.7 16.4 4.60 3.91 3.68 3.45 3.17 2.47 1.98 18400 12700
Table 2. Dry grade stresses of timber (N/mm2)
Moisture content 19 % (continued)
12
© STANDARDS MALAYSIA 2015 - All rights reserved 27
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
35 Kelat
23.1 18.2 14.4 13.9 10.9 8.6 24.3 19.2 15.2 2.87 2.44 2.30 2.15 2.82 2.20 1.76 17300 10700
36 Keledang 15.9 12.5 9.9 9.5 7.5 5.9 12.9 10.1 8.0 2.24 1.90 1.79 1.683)
1.79 1.39 1.12 11900 7200
37 Kembang semangkok
24.1 19.0 15.0 14.5 11.4 9.0 22.2 17.5 13.9 2.73 2.32 2.18 2.053)
2.07 1.61 1.30 16500 13700
38 Kempas 23.3 18.3 14.6 14.0 11.0 8.8 24.9 19.6 15.6 4.16 3.54 3.33 3.12 2.53 1.97 1.58 17700 14000
39 Keranji 27.4 21.6 17.2 16.4 13.0 10.3 22.9 18.0 14.3 4.13 3.51 3.30 3.103)
2.43 1.89 1.52 19800 14700
40 Keruing 17.5 13.8 11.0 10.5 8.3 6.6 15.4 12.1 9.6 2.11 1.79 1.67 1.58 1.99 1.55 1.25 12000 7500
41 Keruntum 20.8 16.4 13.0 12.5 9.8 7.8 19.9 15.7 12.4 3.00 2.55 2.40 2.253)
1.99 1.55 1.24 15800 11200
42 Ketapang 17.8 14.0 11.1 10.7 8.4 6.7 13.6 10.7 8.5 1.91 1.62 1.53 1.43 1.95 1.52 1.22 10700 9300
43 Kulim 24.7 19.4 15.4 14.8 11.6 9.2 22.5 17.7 14.1 2.77 2.35 2.22 2.08 2.33 1.81 1.46 14300 11000
44 Kungkur 19.1 15.0 11.9 11.5 9.0 7.1 14.5 11.4 9.0 2.66 2.26 2.13 2.003)
2.09 1.62 1.31 10600 7300
45 Laran 9.9 7.8 6.2 5.9 4.7 3.7 9.6 7.6 6.0 1.30 1.10 1.04 0.973)
1.22 0.95 0.76 7600 4400
46 Machang 13.9 10.9 8.7 8.3 6.5 5.2 11.8 9.3 7.4 2.74 2.33 2.19 2.06 2.33 1.81 1.46 7300 6300
47 Malabera 20.3 16.0 12.7 12.2 9.6 7.6 16.2 12.7 10.1 3.79 3.22 3.03 2.84 1.94 1.53 1.21 13500 10400
48 Mata ulat 31.2 24.6 19.5 18.7 14.8 11.7 25.9 20.4 16.2 4.93 4.19 3.94 3.70 2.92 2.27 1.82 16800 15300
49 Medang 16.0 12.6 10.0 9.6 7.6 6.0 14.4 11.3 9.0 1.44 1.22 1.15 1.08 1.74 1.35 1.08 8000 7800
50 Melantai/Kawang 11.8 9.3 7.4 7.1 5.6 4.4 10.6 8.3 6.6 1.35 1.15 1.08 1.01 1.25 0.97 0.78 10900 6300
51 Melunak 14.7 11.6 9.2 8.8 7.0 5.5 15.7 12.3 9.8 2.15 1.83 1.72 1.61 1.87 1.46 1.17 11500 7600
Table 2. Dry grade stresses of timber (N/mm2)
moisture content 19 % (continued)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
Perpendicular to grain1)
Shear
parallel to grain
Modulus of elasticity for all
grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
52 Mempening 21.9 17.3 13.7 13.1 10.3 8.2 18.6 14.6 11.6 3.68 3.13 2.94 2.76 2.53 1.97 1.58 17500 11300
53 Mempisang 16.1 12.7 10.1 9.7 7.6 6.1 14.6 11.5 9.1 1.95 1.66 1.56 1.46 1.68 1.31 1.05 13100 7900
54 Mengkulang 17.8 14.0 11.1 10.7 8.4 6.7 13.4 10.6 8.4 2.47 2.10 1.98 1.85 2.20 1.71 1.37 10900 6700
55 Meransi 24.2 19.0 15.1 14.5 11.4 9.1 19.5 15.4 12.2 4.68 3.98 3.74 3.51 2.53 1.96 1.58 12800 10300
56 Meranti bakau 18.2 14.3 11.4 10.9 8.6 6.8 14.1 11.1 8.8 2.06 1.75 1.65 1.54 1.80 1.40 1.13 15000 11200
57 Meranti, dark red 18.2 14.3 11.4 10.9 8.6 6.8 13.9 11.0 8.7 1.53 1.30 1.22 1.15 1.89 1.47 1.18 11200 10000
58 Meranti, light red 13.3 10.4 8.3 8.0 6.2 5.0 11.4 8.9 7.1 1.23 1.04 0.98 0.92 1.11 0.86 0.69 9800 7200
59 Meranti, white 17.1 13.5 10.7 10.3 8.1 6.4 15.7 12.3 9.8 1.62 1.38 1.30 1.21 1.55 1.20 0.97 11200 6300
60 Meranti, yellow 13.2 10.4 8.2 7.9 6.2 4.9 12.4 9.8 7.7 1.73 1.47 1.38 1.30 1.25 0.97 0.78 10800 8100
61 Merawan 25.1 19.8 15.7 15.1 11.9 9.4 23.0 18.1 14.4 2.95 2.51 2.36 2.21 1.91 1.48 1.19 15500 11000
13
14
28 © STANDARDS MALAYSIA 2015 - All rights reserved
62 Merbatu 29.0 22.8 18.1 17.4 13.7 10.9 23.8 18.8 14.9 4.07 3.46 3.25 3.05 2.51 1.95 1.57 19400 13800
63 Merbau 24.6 19.4 15.4 14.8 11.6 9.2 17.9 14.1 11.2 4.00 3.40 3.20 3.00 2.57 2.00 1.61 14800 9100
64 Merpauh 19.2 15.1 12.0 11.5 9.1 7.2 17.4 13.7 10.9 3.22 2.74 2.58 2.41 2.62 2.04 1.64 15400 10400
65 Mersawa 14.7 11.6 9.2 8.8 7.0 5.5 11.5 9.1 7.2 2.42 2.06 1.94 1.81 1.72 1.34 1.08 9700 5200
66 Mertas 28.5 22.4 17.8 17.1 13.4 10.7 23.4 18.5 14.7 3.82 3.25 3.05 2.863) 2.53 1.97 1.58 17300 13800
67 Nyalin 22.5 17.7 14.1 13.5 10.6 8.5 19.6 15.5 12.3 4.44 3.77 3.55 3.33 3.17 2.46 1.98 14300 9500
68 Nyatoh 16.2 12.3 10.1 9.7 7.7 6.1 14.5 11.4 9.0 2.08 1.77 1.66 1.56 1.99 1.55 1.25 11300 8700
Table 2. Dry grade stresses of timber (N/mm2)
moisture content 19 % (continued)
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
perpendicular to grain1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
69 Pauh kijang 25.0 19.7 15.603
)
15.0 11.8 9.43)
27.7 21.8 17.3 4.80 4.08 3.84 3.63)
3.35 2.60 2.09 18000 12100
70 Pelajau 9.1 7.2 5.7 5.5 4.3 3.4 10.3 8.1 6.4 0.77 0.65 0.62 0.58 0.98 0.76 0.61 8800 4200
71 Penaga 35.3 27.8 22.1 21.2 16.7 13.3 33.9 26.8 21.2 8.55 7.27 6.84 6.41 4.17 3.24 2.61 18800 15800
72 Penarahan 14.3 11.3 8.9 8.6 6.8 5.3 13.0 10.2 8.1 4.30 3.65 3.44 3.22 1.60 1.25 1.00 9600 77003)
73 Penyau 3)
26.9 21.2 16.8 16.1 12.7 10.1 27.0 21.3 16.9 6.74 5.73 5.39 5.05 2.80 2.18 1.75 18600 12500
74 Perah 21.8 17.2 13.6 13.1 10.3 8.2 27.0 21.3 16.9 2.99 2.54 2.39 2.24 3.31 2.58 2.07 15200 10300
75 Perupok 20.6 16.2 12.9 12.4 9.7 7.7 17.9 14.1 11.2 2.80 2.38 2.24 2.10 1.58 1.23 0.99 12200 8300
76 Petai 12.1 9.5 7.5 7.3 5.7 4.5 11.0 8.6 6.8 1.55 1.32 1.24 1.163)
1.37 1.07 0.86 10200 7100
77 Petaling 21.2 16.6 13.2 12.7 10.0 7.93)
22.4 17.6 14.0 2.61 2.22 2.09 1.96 2.38 1.85 1.48 15400 10400
78 Pulai 9.0 7.0 5.6 5.4 4.2 3.4 7.7 6.0 4.8 1.02 0.87 0.82 0.763)
1.10 0.86 0.69 6900 3800
79 Punah 25.4 20.0 15.8 15.2 12.0 9.5 21.5 16.9 13.4 3.58 3.04 2.86 2.68 2.44 1.90 1.52 15400 13300
80 Ramin 19.8 15.5 12.3 11.9 9.3 7.4 17.0 13.4 10.6 2.15 1.83 1.72 1.613)
1.73 1.35 1.08 15700 12100
81 Ranggu 25.2 19.8 15.7 15.1 11.9 9.4 22.9 18.0 14.3 3.65 3.10 2.92 2.74 2.47 1.92 1.54 16600 11600
82 Rengas 23.1 18.2 14.4 13.9 10.2 8.6 15.2 12.0 9.5 3.32 2.82 2.65 2.49 2.83 2.20 1.77 14600 11500
83 Resak 23.4 18.4 14.6 14.0 11.0 8.8 17.0 13.4 10.6 3.27 2.78 2.62 2.45 1.99 1.55 1.25 14600 8600
84 Rubberwood 13.9 11.0 8.7 8.3 6.6 5.2 10.8 8.5 6.7 2.68 2.28 2.14 2.01 2.57 2.00 1.61 9100 6400
85 Sengkuang 3)
19.8 15.6 12.4 11.9 9.4 7.4 18.3 14.4 11.4 2.59 2.20 2.07 1.94 2.36 1.84 1.48 12000 8100
Table 2. Dry grade stresses of timber (N/mm2)
moisture content 19 % (concluded)
15
© STANDARDS MALAYSIA 2015 - All rights reserved 29
Timber
Bending
parallel to grain
Tension
parallel to grain
Compression
parallel to grain
Compression
Perpendicular to grain1)
Shear
parallel to grain
Modulus of
elasticity for all grades
Sel Std Com2) Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
86 Sepetir 13.2 10.3 8.2 7.9 6.2 4.9 11.2 8.8 7.0 2.42 2.06 1.94 1.81 2.38 1.85 1.48 13000 7600
87 Sesendok 12.2 9.6 7.6 7.3 5.8 4.6 10.9 8.5 6.8 1.11 0.94 0.89 0.83 1.37 1.06 0.85 8600 7200
88 Simpoh 18.1 14.2 11.3 10.9 8.5 6.8 20.8 16.4 13.0 3.14 2.67 2.51 2.35 1.70 1.33 1.06 14400 9500
89 Surian batu 23.8 18.7 14.8 14.3 11.2 8.9 21.6 17.0 13.5 6.13 5.20 4.90 4.60 3.70 2.91 2.31 14300 11900
90 Teak 17.9 14.1 11.2 10.7 8.5 6.7 14.9 11.7 9.3 3.12 2.65 2.50 2.34 2.56 1.99 1.60 10300 6300
91 Tembusu 17.3 13.6 10.8 10.4 8.2 6.5 16.5 13.0 10.3 3.75 3.19 3.00 2.813) 1.68 1.30 1.05 13600 6800
92 Terap 11.4 8.9 7.1 6.8 5.3 4.3 8.8 6.9 5.5 1.68 1.43 1.34 1.26 1.76 1.37 1.10 10100 5500
93 Terentang 8.2 6.5 5.1 4.9 3.9 3.1 6.9 5.4 4.3 0.95 0.80 0.76 0.71 1.20 0.93 0.75 6600 3400
94 Tualang 25.7 20.2 16.1 15.4 12.1 9.7 20.4 16.1 12.8 4.00 3.40 3.20 3.00 3.08 2.40 1.93 17500 11500
1) When there is no wane at the bearing area, the basic stress figures may be used for all grades.
2) Sel, Std and Com stand for select structural, standard structural and common building grades respectively as defined in the MS 1714:2003.
3) Figures are estimated due to data not fully available but can be safely used in design.
Table 3. Strength groups of timber
S.G. 1 S.G.2 S.G. 3 S.G. 4 S.G. 5 S.G. 6 S.G. 7
A) Naturally Durable
Balau Belian Bekak Giam Teak
Bitis Mata ulat Delek Malabera Tembusu
Chengal Kekatong Keranji Merbau
Penaga Resak
B) Requiring Treatment
Dedaru Agoho Berangan Alan bunga Bayur Ara
Kempas Balau, red Dedali Babai Damar Minyak Batai
Merbatu Kelat Derum Balek angin bopeng Durian Geronggang
Mertas Kembang semangkok
Kapur Bintangor Jelutong Laran
Kulim Kasai Brazil nut Jenitri Pelajau
Pauh kijang Keruntum Gerutu Jongkong Pulai
Penyau Mempening Kayu kundur Kasah Sesendok
Perah Meransi Kedondong Machang Terentang
Petaling Meranti bakau Keledang Medang
Ranggu Merawan Keruing Melantai/Kawang
Durian batu Merpauh Ketapang Meranti, light red
Tualang Nyalin Kungkur Meranti, yellow
Perupok Melunak Mersawa
16
30 © STANDARDS MALAYSIA 2015 - All rights reserved
Punah Mempisang Terap
Rengas Mengkulang
Simpoh Meranti, dark red
Meranti, white
Nyatoh
Penarahan
Petai Ramin
Rubberwood
Sengkuang
Sepetir
NOTES: 1. For naturally durable timbers, sapwood should be excluded. If sapwood is included, preservative treatment is necessary as defined in MS 360:2006. 2. For timber requiring treatment, they should be amenable to preservative treatment.
© STANDARDS MALAYSIA 2015 - All rights reserved 31
Table 4. Wet and dry grade stresses for various strength groups of timber (Stresses and moduli expressed in N/mm
2)
Strength groups
Condition 1)
Bending
parallel to grain Tension
parallel to grain Compression
parallel to grain Compression
perpendicular to grain2)
Shear parallel to
grain Modulus of elasticity
for all grades
Sel Std Com3)
Sel Std Com Sel Std Com Basic Sel Std Com Sel Std Com Mean Minimum
SG 1 Wet 29.2 23.0 18.2 17.5 13.8 10.9 26.8 21.1 16.8 4.59 3.90 3.67 3.44 2.54 1.98 1.59 17000 13300
Dry 33.6 26.5 21.0 20.2 15.9 12.6 28.5 22.5 17.8 4.67 3.97 3.74 3.50 2.94 2.28 1.84 18800 14000
SG 2 Wet 20.7 16.3 13.0 12.4 9.8 7.8 18.8 14.8 11.7 3.50 2.97 2.80 2.62 2.24 1.74 1.40 15700 11700 Dry 23.3 18.3 14.6 14.0 11.0 8.8 23.4 18.5 14.7 3.82 3.25 3.05 2.86 2.51 1.95 1.57 16800 12600
SG 3 Wet 18.1 14.2 11.3 10.9 8.5 6.8 15.3 12.0 9.5 2.38 2.02 1.90 1.78 1.84 1.43 1.15 13300 9800 Dry 20.2 15.9 12.6 12.1 9.5 7.6 17.8 14.1 11.1 2.61 2.22 2.09 1.96 2.07 1.61 1.30 14300 10300
SG 4 Wet 14.2 11.2 8.8 8.5 6.7 5.3 12.1 9.5 7.6 1.83 1.55 1.46 1.37 1.53 1.19 0.96 10700 7400 Dry 16.8 13.2 10.5 10.1 7.9 6.3 14.1 11.1 8.8 2.06 1.75 1.65 1.54 1.58 1.23 0.99 11000 7600
SG 5 Wet 11.0 8.6 6.8 6.6 5.2 4.1 9.1 7.2 5.7 1.12 0.95 0.90 0.84 1.21 0.95 0.76 8800 6100 Dry 12.1 9.5 7.5 7.3 5.7 4.5 10.8 8.5 6.7 1.42 1.21 1.14 1.06 1.37 1.07 0.86 9100 6300
SG 6 Wet 9.4 7.4 5.9 5.6 4.4 3.5 7.9 6.2 5.0 1.02 0.87 0.82 0.76 1.05 0.82 0.66 6700 4900 Dry 11.3 8.9 7.1 6.8 5.3 4.3 8.8 6.9 5.5 1.28 1.09 1.02 0.96 1.11 0.86 0.69 7300 5200
SG 7 Wet 6.6 5.2 4.2 4.0 3.1 2.5 5.3 4.2 3.3 0.62 0.53 0.50 0.46 0.91 0.71 0.57 5700 3000 Dry 8.2 6.5 5.1 4.9 3.9 3.1 6.9 5.4 4.3 0.77 0.65 0.62 0.58 0.98 0.76 0.61 6600 3400
1)
Moisture content for Wet 19 %, for dry 19 %. 2)
When there is no wane at the bearing area, the basic stress figures may be used for all grades. 3)
Sel, Std and Com stand for select structural, standard structural and common building grades respectively as defined in MS 1714:2003.
9. Permissible stresses
9.1 General
Permissible stresses in timber are governed by the particular conditions of service and loading.
9.2 Load inclined to grain
Where the direction of the load is inclined to the grain by an angle , the permissible compression
stress for the inclined surface is given by the equation:
32 © STANDARDS MALAYSIA 2015 - All rights reserved
where c,adm,ll and c,adm, are the grade compression stresses parallel and perpendicular to the grain
respectively, modified as appropriate, for moisture content (Tables 1 and 2) and / or duration of load
(see Clause 10).
9.3 Additional properties
In the absence of specific test data, values which are one-third of those for shear parallel to the grain
(see Table 1 and 2) should be use for tension perpendicular to the grain, torsional shear and rolling
shear.
For modulus of elasticity perpendicular to grain, a value of one-twentieth (i.e. 0.05) of permissible
modulus of elasticity (see Table 1 and 2) should be used.
For shear modulus, a value of one-sixteenth (i.e. 0.0625) of permissible modulus of elasticity (see Table 1 and 2) should be used.
10. Duration of loading The stresses given in Tables 1, 2 and 4 apply to long term loading. Table 5 gives the modification
factor K1 by which these should be multiplied for various duration of loading. When advantage is taken
of this clause to use a modification factor K1, greater than unity, the design should be checked to
ensure that the permissible stresses are not exceeded for any other condition of loading that might be
relevant. This modification factor is applicable to all strength properties but is not applicable to moduli
of elasticity or to shear moduli.
NOTE. For domestic floors, the possible concentrated loading condition is given in MS 544, Part 11, Section1: Domestic Floor
Joists may be superimposed on the dead load and both treated as of medium term duration.
Table 5. Modification factor K1 for duration of loading
Duration of loading Value of K1
Long term (e.g. dead + permanent imposed 1)
)
Medium term (dead + temporary imposed)
Short term (e.g. dead + imposed + wind
2))
1.00
1.25
1.50
NOTES: 1)
For uniformly distributed imposed floor loads K1 = 1 except for type 2 and
type 3 buildings. Refer UBBL: 1984 where, for corridors, hallways, landings and stairways only, K1 may be assumed to be 1.5.
© STANDARDS MALAYSIA 2015 - All rights reserved 33
2) For wind, short term category applies to 3s gust as defined in MS 1553:2002.
11. Load-sharing systems In a load-sharing system which consists of four or more members such as rafters, joists, trusses or
wall studs, spaced a maximum of 610 mm centre to centre, and which has adequate provision for the
lateral distribution of loads by means of purlins, binders, boarding, battens, etc., the following
permissible stresses and moduli of elasticity appropriate to the strength class or species and grade
should apply.
a) The appropriate grade stresses should be multiplied by the load sharing modification factor K2
which has a value of 1.1.
b) The mean modulus of elasticity should be used to calculate deflections and displacements
under both dead and imposed load unless the imposed load is for an area intended for
mechanical plant and equipment, or for storage, or for floors subject to vibrations, e.g.
gymnasia and ballrooms, in which case the minimum modulus of elasticity should be used.
Special provisions for built-up beams, trimmer joists and lintels, and laminated beams, are given in 12.10, 12.11 and MS 544-3:2001 respectively.
The provisions of this clause do not extend to the calculation of modification factor K8 given in Table
10 and Annex B for load-sharing columns.
12 Flexural members
12.1 General
Permissible stresses for timber flexural members are governed by the particular conditions of loading
as given in Clauses 10 and by the additional factors given in this clause. They should be taken as the
product of the grade stress given in Clause 8 and the appropriate modification factors.
12.2 Length and position of bearing
The grade stresses for compression perpendicular to the grain apply to bearings of any length at the
ends of a member, and bearings 150 mm or more in length at any position.
34 © STANDARDS MALAYSIA 2015 - All rights reserved
For bearings less than 150 mm long located 75 mm or more from the end of a member, as shown in
Figure 1 the grade stress should be multiplied by the modification factor K3 given in Table 6.
NOTES: 1. At any bearing on the side grain of timber, the permissible stress in compression perpendicular to the grain is dependent on the length and position of the bearing.
2. No allowance need be made for the difference in intensity of the bearing stress due to rotation of a beam at the supports.
75 mm or Bearing less than
more 150 mm
Figure 1. Position of end bearing
© STANDARDS MALAYSIA 2015 - All rights reserved 35
Table 6. Modification factor K3 for bearing stress
Length of
bearing 1)
(mm)
10
15
25
40
50
75
100
150 or
more
Value of K3
1.74
1.67
1.53
1.33
1.20
1.14
1.10
1.00
1) Interpolation is permitted
12.3 Effective span
The span of flexural members should be taken as the distance between the centres of bearings.
Where members extend over bearings which are longer than is necessary, the spans may be
measured between the centres of bearings of a length which could be adequate according to this part
of MS 544: Part 2. Where advantage is taken of this clause, due attention should be paid to the
eccentricity of the load on the supporting structure.
12.4 Shear at notched ends
Square cornered notches at the ends of a flexural member cause a stress concentration, which
should be allowed for as follows.
The shear strength should be calculated by using the effective depth, he (see Figure 2) and a
permissible stress equal to the grade stresses multiplied by the factor K4
where,
a) for a notch on the top edge (see Figure 2(a))
for a ≤
for a
b) for a notch on the underside (see Figure 2 (b)),
36 © STANDARDS MALAYSIA 2015 - All rights reserved
The effective depth, he should be not less than 0.6 h. (0.5 in BS5268 2002)
where,
h is the total depth of the beam (mm);
a is as shown in Figure 2 (mm).
a
h he
a) Beam with notch on the top edge
he h
b) Beam with notch on the underside.
Figure 2. Notched beams
12.5 Form factor
Grade bending stresses apply to solid timber members of rectangular cross section. For other shapes of cross section, the grade bending stresses should be multiplied by the modification factor K5 where,
K5 = 1.18 for solid circular sections; and
K5 = 1.41 for solid square sections loaded on a diagonal.
© STANDARDS MALAYSIA 2015 - All rights reserved 37
12.6 Depth factor
The grade bending stresses given in Tables 1, 2 and 4, apply to material having a depth, h, up to 300
mm.
For depths of beams greater than 300 mm, the grade bending stresses should be multiplied by the
depth modification factor K6 where:
(h2
+ 92300)
K6 = 0.81 for solid and glued laminated beams. (h
2 + 56800)
12.7 Deflection and stiffness
The dimensions of flexural member should be such as to restrict deflection within limits appropriate to
the type of structure, having regard to the possibility of damage to surfacing materials, ceilings,
partitions and finishing, and to the functional needs as well as aesthetic requirements.
In addition to the deflection due to bending, the shear deflection may be significant and should be
taken into account.
For most general purposes, this recommendation may be assumed to be satisfied if the deflection of
the member when fully loaded does not exceed 0.003 of the span. For domestic floor joists, the
deflection under full load should not exceed the lesser of 0.003 times the span or 14 mm, whichever is
lesser.
NOTE. The 14 mm deflection limitation is to avoid undue vibration under moving or impact loading.
Subject to consideration being given to the effect of excessive deformation, members may be
precambered to account for the deflection under full dead or permanent load, and in this case the
deflection under live or intermittent load should not exceed 0.003 of the span.
The deflection of solid timber members acting alone should be calculated using the minimum modulus
of elasticity for the strength group or species and grade.
The deflections of load-sharing systems, built-up beams, trimmer joists and lintels should be
calculated using the provisions of Clauses 11, 12.10 and 12.11 respectively.
12.8 Lateral support
The depth to breadth ratio of solid and laminated beams of rectangular section should be checked to ensure that there is no risk of buckling under design load. Alternatively, the recommendations of Table 7 should be followed.
38 © STANDARDS MALAYSIA 2015 - All rights reserved
Table 7. Maximum depth to breadth ratios (solid and laminated members)
Degree of lateral support Maximum depth
to breadth ratio
No lateral support 2
Ends held in position 3
Ends held in position and member held in line as by purlins or tie rods
at centres not more than 30 times breadth of the member
4
Ends held in position and compression edge held in line, as by direct
connection of sheathing, deck or joists
5
Ends held in position and compression edge held in line, as by direct
connection of sheathing, deck or joists, together with adequate bridging
or blocking spaced at intervals not exceeding 6 times the depth.
6
Ends held in position and both edges held firmly in line 7
12.9 Notched or drilled beams
In calculating the strength of notched or drilled beams, allowance should be made for the notches or
holes, the effective depth being taken as the minimum depth of the net section.
The effect of notches and holes need not be calculated in simply supported floor and roof-joist not
more than 250 mm deep where:
a) notches not exceeding 0.125 of the depth of a joist are located between 0.07 and 0.25 of the
span from the support; and
b) holes drilled at the neutral axis with diameter not exceeding 0.25 of the depth of a joist and
not less than three diameters (centre to centre) apart are located between 0.25 and 0.4 of the span from the support.
12.10 Built - up beams
Built-up beams should be checked to ensure that there is no risk of buckling under design load.
In built-up members with thin webs, web stiffeners should be provided to ensure the strength and
stability of the member at all points of concentrated load, or elsewhere as may be necessary.
The lateral stability should be determined by calculation, or by consideration of the compression
flange as a column which tends to deflect sideways between points of lateral support, or in
accordance with one of the following:
a) if the ratio of the second moments of area of the cross section about the neutral axis to the
second moment of area about the axis perpendicular to the neutral axis does not exceed 5 :
1, no lateral support is required;
b) if the ratio of the second moments of area is between 5 : 1 and 10 : 1, the ends of the beam
should be held in position at the bottom flange at the supports;
© STANDARDS MALAYSIA 2015 - All rights reserved 39
c) if the ratio of the second moments of area is between 10 : 1 and 20 : 1, the beam should be
held in line at the ends;
d) if the ratio of the second moments of area is between 20 : 1 and 30 : 1, one edge should be
held in line;
e) if the ratio of the second moments of area is between 30 : 1 and 40 : 1, the beam should be
restrained by bridging or other bracing at intervals of not more than 2.4 m; and
f) if the ratio of the second moments of area is greater than 40 : 1, the compression flanges
should be fully restrained.
The modification factors K17, K18 and K19 given in Table 7 of MS 544 : Part 3: 2001: Code Of Practice
For Structural Use Of Timber: Part 3 : Permissible Stress Design Of Glued Laminated Timber may be
used for the flanges of glued built-up beams such as box and I-beams. The number of pieces of
timber in each flange should be taken as the number of laminations, irrespective of their orientation, to
determine the value of the stress modification factor K17, K18, and K19 for that flange.
The total number of pieces of timber in both flanges should be taken as the number of laminations to
determine the value of K18 that is to be applied to the minimum modulus of elasticity for deflection
calculations.
In addition to the deflection of a built-up beam due to bending, the shear deflection may be significant
and should be taken into account.
12.11 Trimmer joists and lintels
For trimmer joists and lintels comprising two or more pieces connected together in parallel and acting
together to support the loads, the grade stresses in bending and shear parallel to the grain, and in
compression perpendicular to the grain should be multiplied by the load-sharing stress modification
factor K2, which has a value of 1.1.
The minimum modulus of elasticity modified by the factor K7 given in Table 8 should be used for the
calculation of deflection.
Table 8. Modification factor K7 used to modify the minimum
modulus of elasticity for trimmer joists and lintels
Number of pieces Values of K7 Values of K,
1 1.00
2 1.06
3 1.08
4 or more 1.10
40 © STANDARDS MALAYSIA 2015 - All rights reserved
13 Compression members 13.1 General
The limitations on bow in most stress grading rules are inadequate for the selection of material for
columns. Particular attention should therefore be paid to the straightness of columns, e.g. by limiting
bow to approximately 1/300 of the length.
Permissible stresses for timber members subjected to compression in the direction of the grain are
governed by the particular conditions of loading given in Clauses 10 and 11 and by the additional
factors given in this clause.
13.2 Size factors
The grade compression stresses given in Tables 1, 2 and 4 apply to all solid timber members graded
in accordance with MS 1714: 2003. 13.3 Effective length
The effective length of a compression member should be derived from either:
a) Table 9 for the particular end conditions; or
b) the deflected form of the compression member as affected by any restraint and/or fixing
moment(s), the effective length being the distance between adjacent points of zero bending
between which the member is in single curvature.
Table 9. Effective length of compression members
End conditions Effective length
Actual length L
Restrained at both ends in position and in direction 0.7
Restrained at both ends in position and one end in
direction
0.85
Restrained at both ends in position but not in
direction
1.0
Restrained at one end in position and at the other
end in direction but not in position
1.5
Restrained at one end in position and in direction
and free at the other end
2.0
© STANDARDS MALAYSIA 2015 - All rights reserved 41
13.4 Slenderness ratio
The slenderness ratio, of compression members should be calculated as the effective length, Le
divided by the radius of gyration, i.
The slenderness ratio should not exceed 180 for:
a) any compression member carrying dead and imposed loads other than loads resulting from
wind; and
b) any compression member, however loaded, which by its deformation will adversely affect the
stress in another member carrying dead and imposed loads other than wind.
The slenderness ratio should not exceed 250 for:
a) any member normally subject to tension or combined tension and bending arising from dead
and imposed loads, but subject to a reversal of axial stress solely from the effect of wind; and
b) any compression member carrying self weight and wind loads only (e.g. wind bracing).
13.5 Members subject to axial compression (without bending)
For compression members with slenderness ratios of less than 5, without undue eccentricity of
loading, the permissible stress should be taken as the grade compression parallel to the grain stress
modified as appropriate for duration of load and load sharing (Clauses 10 and 11).
For compression members with slenderness ratios equal to or greater than 5, the permissible stress
should be calculated as the product of the grade compression parallel to the grain stress, modified as
appropriate for size, moisture content, duration of load and load sharing, and the modification factor,
K8 given in Table 10 or calculated using the equation in Annex B.
The value of modulus of elasticity used to enter Table 10 or the equation in Annex B for both
compression members acting alone and compression members in load-sharing systems should be
the minimum modulus of elasticity. For members comprising two or more pieces connected together
in parallel and acting together to support the loads, the minimum modulus of elasticity should be
modified by K7 ( see Table 8 ) or K18 (see Table 7 of MS 544: Part 3: 2001) for horizontally laminated
members, the modified mean modulus of elasticity should be used (see Clauses 4 and 8 of MS 544 :
Part 3: 2001). The compression parallel to the grain stress c used to enter Table 10 or the equation in
Appendix B should be the grade stress modified only for duration of loading, and size where
applicable.
When checking that the permissible stresses of a compression member are not exceeded,
consideration should be given to all relevant loading conditions, since in the expression E/ c,ll , used to
enter Table 10 or the equation in Annex B, the modulus of elasticity is constant for all load duration,
whereas the compression stress should be modified for duration of loading (Clause 10).
30 © STANDARDS MALAYSIA 2015 - All rights reserved
Table 10. Modification factor K8 for compression members
Value of K8
Values of slenderness ratio (= Le/i )
E/ c,ll < 5 5 10 20 30 40 50 60 70 80 90 100 120 140 160 180 200 220 240 250
Equivalent Le/b (for rectangular sections)
< 1.4 1.4 2.9 5.8 8.7 11.6 14.5 17.3 20.2 23.1 26 28.9 34.7 40.5 46.2 52 57.8 63.6 69.4 72.3
400 1.000 0.975 0.951 0.896 0.827 0.735 0.621 0.506 0.408 0.330 0.271 0.225 0.162 0.121 0.094 0.075 0.061 0.051 0.043 0.040
500 1.000 0.975 0.951 0.899 0.837 0.759 0.664 0.562 0.466 0.385 0.320 0.269 0.195 0.148 0.115 0.092 0.076 0.063 0.053 0.049
600 1.000 0.975 0.951 0.901 0.843 0.774 0.692 0.601 0.511 0.430 0.363 0.307 0.226 0.172 0.135 0.109 0.089 0.074 0.063 0.058
700 1.000 0.975 0.951 0.902 0.848 0.784 0.711 0.629 0.545 0.467 0.399 0.341 0.254 0.195 0.154 0.124 0.102 0.085 0.072 0.067
800 1.000 0.975 0.952 0.903 0.851 0.792 0.724 0.649 0.572 0.497 0.430 0.371 0.280 0.217 0.172 0.139 0.115 0.096 0.082 0.076
900 1.000 0.976 0.952 0.904 0.853 0.797 0.734 0.665 0.593 0.522 0.456 0.397 0.304 0.237 0.188 0.153 0.127 0.106 0.091 0.084
1000 1.000 0.976 0.952 0.904 0.855 0.801 0.742 0.677 0.609 0.542 0.478 0.420 0.325 0.255 0.204 0.167 0.138 0.116 0.099 0.092
1100 1.000 0.976 0.952 0.905 0.856 0.804 0.748 0.687 0.623 0.599 0.497 0.440 0.344 0.272 0.219 0.179 0.149 0.126 0.107 0.100
1200 1.000 0.976 0.952 0.905 0.857 0.807 0.753 0.695 0.634 0.573 0.513 0.457 0.362 0.288 0.233 0.192 0.160 0.135 0.116 0.107
1300 1.000 0.976 0.952 0.905 0.858 0.809 0.757 0.757 0.643 0.584 0.527 0.472 0.378 0.303 0.247 0.203 0.170 0.144 0.123 0.115
1400 1.000 0.976 0.952 0.906 0.859 0.811 0.760 0.760 0.651 0.595 0.539 0.486 0.392 0.317 0.259 0.214 0.180 0.153 0.131 0.122
1500 1.000 0.976 0.952 0.906 0.860 0.813 0.763 0.763 0.658 0.603 0.550 0.498 0.405 0.330 0.271 0.225 0.189 0.161 0.138 0.129
1600 1.000 0.976 0.952 0.906 0.861 0.814 0.766 0.766 0.664 0.611 0.559 0.508 0.417 0.342 0.282 0.235 0.198 0.169 0.145 0.135
1700 1.000 0.976 0.952 0.906 0.861 0.815 0.768 0.768 0.669 0.618 0.567 0.518 0.428 0.353 0.292 0.245 0.207 0.177 0.152 0.142
1800 1.000 0.976 0.952 0.906 0.862 0.816 0.770 0.770 0.673 0.624 0.574 0.526 0.438 0.363 0.302 0.254 0.215 0.184 0.159 0.148
1900 1.000 0.975 0.952 0.907 0.862 0.817 0.772 0.772 0.677 0.629 0.581 0.534 0.447 0.373 0.312 0.262 0.223 0.191 0.165 0.154
2000 1.000 0.976 0.952 0.907 0.863 0.818 0.773 0.773 0.681 0.634 0.587 0.541 0.455 0.382 0.320 0.271 0.230 0.198 0.172 0.160
MS
54
4 : P
AR
T 2
: 200
1
© STANDARDS MALAYSIA 2015 - All rights reserved 31
13.6 Members subject to axial compression and bending
A member restrained at both ends, in position but not in direction, and subject to bending and axial
compression should be so proportioned that:
where,
is the applied bending stress;
is the permissible bending stress;
is the applied compression stress
is the permissible compression stress (including ; and
is the Euler critical stress where E is the modulus of elasticity given in 13.5.
The effective length of a member subject to axial compression and bending should be that given in 13.3b.
For members in load-sharing systems (see Clause 10), the permissible bending stress, m,adm,II and
the permissible compression stress c,adm,II, should be multiplied by the load-sharing stress modification factor K2, which has a value of 1.1, or K17 or K18 ,of MS 544 : Part 3: 2001: 2001 as applicable. The dimensions of compression members subject to bending should be such as to restrict deflection within limits appropriate to the type of structure. 13.7 Notching and drilling
When it is necessary to notch or drill a compression member, allowance for the notches or holes should be made in the design. NOTE. The effect of holes need not be calculated where circular holes with diameters not exceeding 25 % of the width of the member are positioned on the neutral axis at between 25 % and 40 % of the actual length from the end or from a support.
13.8 Spaced columns A spaced column is composed of two or more equal shafts, spaced apart by end and intermediate packing blocks, which are glued, bolted, screwed, nailed or connectored in position in accordance with Clause 13.9 and MS 544 - 5: 2001. The clear space between individual shafts (in which packings are inserted), should not be greater than three times the thickness of the shaft, measured in the same plane.
32 © STANDARDS MALAYSIA 2015 - All rights reserved
13.9 Packs for spaced columns 13.9.1 End packs
13.9.1.1 Mechanical connections End packings should be of a length sufficient to accommodate the nails, screws or connectors required to transmit, between the abutting face of the packing and one adjacent shaft, a shear force equal to:
where, A is the total section area of the column; b is the thickness of the shaft;
c,a,II is the applied compression stress;
n is the number of shafts; and a is the distance between the centres of adjacent shafts. In addition, the length of the packing measured along the axis of the column should be not less than six times the thickness of the individual shafts. 13.9.1.2 Glued connections End packings should be of a length sufficient to provide the glue area required to transmit a shear force between the abutting face of the packing and one adjacent shaft, calculated as given for end packings mechanically connected. In addition, the length of the packing measured along the axis of the column should be not less than six times the thickness of the individual shaft. Shop fabrication of spaced columns employing glued packings may be carried out using suitable clamps, or clamping pressure may be obtained by screwing or bolting between column shafts and the packings. In the latter case, at least four screws or bolts should be provided per packing and these should be so spaced as to obtain an even pressure over the area of the packing. 13.9.2 Intermediate packs Intermediate packings should be not less than 230 mm long, measured along the axis of column, and should be designed to transmit, between the abutting face of the packing and one adjacent shaft, a shear force of not less than one half of the corresponding shear force for the end packing (see 13.9.1.1). Where the length of the column does not exceed 30 times the thickness of the shaft, only one intermediate packing need be provided. In any event, sufficient packings should be provided to ensure that the greater slenderness ratio ( Le/i ) of the local portion of an individual shaft between packings is limited to either 70, or to 0.7 times the slenderness ratio of the whole column, whichever is the lesser. For the purpose of calculating the slenderness ratio of the local portion of an individual shaft, the
© STANDARDS MALAYSIA 2015 - All rights reserved 33
effective length (Le ) should be taken as the length between the centroids of the groups of mechanical connectors or glue areas in adjacent packings. 13.10 Permissible stresses for spaced columns For the purpose of calculating the permissible stress on a spaced column, the radii of gyration should be calculated about the axes X-X and Y-Y as indicated in Figure 3.
The effective length of the column, for buckling about the axes X-X and Y-Y, should be assessed in accordance with the requirement of Table 9.
Figure 3. Axes in spaced columns
The permissible load should then be taken as the least of the following: a) that for a solid column (whose area is that of the area of timber) bending about axis X-X; b) that for a solid column whose area is that of one member of the built-up column, and whose
effective length is equal to the spacing of the packing pieces, multiplied by the number of shafts; and
c) that for a column bending about the Y-Y axis whose geometrical properties of cross-section
are those of the built-up column, but whose effective length is multiplied by the modification factor K9 given in Table 11 .
Table 11. Modification factor K9 for the effective length of spaced columns
Method of connection
Value of K9
Ratio of space to thickness of the thinner member
0 1 2 3
Nailed 1.8 2.6 3.1 3.5 Screwed or bolted 1.7 2.4 2.8 3.1 Connectored 1.4 1.8 2.2 2.4 Glued 1.1 1.1 1.3 1.4
X X
Y
X
Y b b
34 © STANDARDS MALAYSIA 2015 - All rights reserved
13.11 Compression members in triangulated frameworks Compression members in triangulated frameworks such as trusses and girders (but excluding trussed rafters designed in accordance with MS 544-11:XXXX,Section 4) should be designed in accordance with the previous clauses subject to the following. a) With continuous compression members, the effective length for the purpose of determining
the slenderness ratio may be taken as between 0.85 and 1.0 (depending upon the degree of fixity and the distribution of load between node points) times the distance between the node points of the framework for buckling in the plane of the framework and times the actual distance between effective lateral restraints for buckling perpendicular to the plane of the framework. With roof trusses, purlins or tiling battens may be taken as providing effective lateral restraints provided they are adequately fastened to the top chord and are carried back to effective bracing or other support.
With roofs employing rafters adequately fastened to a continuous restraint, e.g. a boarded covering, it can be taken that effective lateral restraint is provided along the whole length of the rafter.
b) With non-continuous compression members, such as web members in a framework, the
effective length for buckling depends on the type of connection at the ends of the members and may be calculated using the appropriate end fixity (see Table 9).
Where a single bolt or connector at the end of a compression member permits rotation of the member, its effective length should be taken as the actual distance between bolts or connectors.
Where a web member fastened by glued gusset plates is partially restrained at both ends in position and direction, the effective lengths for buckling in and out of the plane of the truss should be taken as 0.9 times the actual distance between the points of intersection of the lines passing through the centroids of the members connected.
c) The recommendations in the first sentences of 13.9.1.1 and 13.9.2 do not apply to spaced
compression members in triangulated frameworks. Intermediate packings should be not less than 200 mm long and should be fixed in such a manner as to transmit a tensile force parallel to axis X-X, between the individual members, of not less than 2.5 % of the total axial force in the spaced compression member.
14 Tension members 14.1 General Permissible stresses for timber tension members are governed by the particular conditions of loading as given in Clauses 10 and 11 and by the additional factors given in this clause. They should be determined as the product of the grade stress and the appropriate modification factors.
© STANDARDS MALAYSIA 2015 - All rights reserved 35
14.2 Width factor The grade tension stresses given in Tables 1 and 2 apply to solid timber having a width (i.e. the greater transverse dimension), h, of 300 mm. For other widths of members, the grade tension stresses should be multiplied by the width modification factor, K10, where: K10 = 1.17 for solid timber members having a width of 72 mm or less; and K10 = (300/h)
0.11 for solid and glued laminated members having a width greater than 72 mm
13.3 Members subject to axial tension and bending Members subject to both bending and axial tension should be so proportioned that :
where,
is the applied bending stress;
is the permissible bending stress;
is the applied tension stress; and
is the permissible tension stress
© STANDARDS MALAYSIA 2015 - All rights reserved 41
Annex A (normative)
Sizes and geometrical properties of Malaysian structural timbers
Table A1. Common Commercial Timber Sizes
Shape Nominal Size (mm x mm)1
Minimum timber sizes (mm)
Fullsawn Baresawn Dressed Timber
Square 25 x 25 (1” x 1”)
50 x 50 (2” x 2”)
75 x 75 (3” x 3”)
100 x 100 (4” x 4”)
125 x 125 (5” x 5”)
150 x 150 (6” x 6”)
28 x 28
55 x 56
80 x 81
106 x 106
131 x 131
159 x 159
25 x 25
50 x 50
75 x 75
100 x 100
125 x 125
150 x 150
20 x 20
45 x 45
70 x 70
90 x 90
115 x 115
140 x 140
Rectangle 25 x 50 (1” x 2”)
25 x 75 (1” x 3”)
25 x 100 (1” x 4”)
25 x 125 (1” x 5”)
25 x 150 (1” x 6”)
25 x 175 (1” x 7”)
25 x 200 (1” x 8”)
28 x 56
28 x 81
28 x 106
28 x 131
28 x 159
28 x 184
28 x 212
25 x 50
25 x 75
25 x 100
25 x 125
25 x 150
25 x 175
25 x 200
20 x 45
20 x 70
20 x 90
20 x 115
20 x 140
20 x 165
20 x 190
38 x 50 (1½” x 2”)
38 x 75 (1½” x 3”)
38 x 100 (1½” x 4”)
38 x 125 (1½” x 5”)
38 x 150 (1½” x 6”)
38 x 175 (1½” x 7”)
38 x 200 (1½” x 8”)
41 x 56
41 x 81
41 x 106
41 x 131
41 x 159
41 x 184
41 x 212
38 x 50
38 x 75
38 x 100
38 x 125
38 x 150
38 x 175
38 x 200
33 x 45
33 x 70
33 x 90
33 x 115
33 x 140
33 x 165
33 x 190
50 x 75 (2” x 3”)
50 x 100 (2” x 4”)
50 x 125 (2” x 5”)
50 x 150 (2” x 6”)
50 x 175 (2” x 7”)
50 x 200 (2” x 8”)
55 x 81
55 x 106
55 x 131
55 x 159
55 x 184
55 x 212
50 x 75
50 x 100
50 x 125
50 x 150
50 x 175
50 x 200
45 x 70
45 x 90
45 x 115
45 x 140
45 x 165
45 x 190
63 x 100 (2½” x 4”)
63 x 125 (2½” x 5”)
63 x 150 (2½” x 6”)
63 x 175 (2½” x 7”)
63 x 200 (2½” x 8”)
68 x 106
68 x 131
68 x 159
68 x 184
68 x 212
63 x 100
63 x 125
63 x 163
63 x 175
63 x 200
58 x 90
58 x 115
58 x 140
58 x 165
58 x 190
75 x 100 (3” x 4”)
75 x 125 (3” x 5”)
75 x 150 (3” x 6”)
80 x 106
80 x 131
80 x 159
75 x 100
75 x 125
75 x 175
70 x 90
70 x 115
70 x 140
NOTE. Any size of above 150 mm shall be checked for availability
42 © STANDARDS MALAYSIA 2015 - All rights reserved
y
x x
y
Table A2. Geometrical properties of sawn timber at wet condition
Nominal size
Area Second moment of area Section modulus Radius of gyration
X-X Y-Y X-X Y-Y X-X Y-Y
mm x mm mm2 (x10
4)mm
4 (x10
4)mm
4 (x10
4)mm
3 (x10
4)mm
3 mm mm
25 x 25 625 3.2552 3.2552 0.2604 0.2604 7.22 7.22
25 x 38 950 11.4317 4.9479 0.6016 0.3958 10.97 7.22
25 x 50 1250 26.0417 6.5104 1.0417 0.5208 14.43 7.22
25 x 63 1575 52.0931 8.2031 1.6538 0.6563 18.19 7.22
25 x 75 1875 87.8906 9.7656 2.3438 0.7813 21.65 7.22
25 x 100 2500 208.3333 13.0208 4.1667 1.0417 28.87 7.22
25 x 125 3125 406.9010 16.2760 6.5104 1.3021 36.08 7.22
25 x 150 3750 703.1250 19.5313 9.375 1.5625 43.30 7.22
25 x 175 4375 1116.5365 22.7865 12.7604 1.8229 50.52 7.22
25 x 200 5000 1666.6667 26.0417 16.6667 2.0833 57.74 7.22
38 x 38 1444 17.3761 17.3761 0.9145 0.9145 10.97 10.97
38 x 50 1900 39.5833 22.8633 1.5833 1.2033 14.43 10.97
38 x 63 2394 79.1816 28.8078 2.5137 1.5162 18.19 10.97
38 x 75 2850 133.5938 34.2950 3.5625 1.8050 21.65 10.97
38 x 100 3800 316.6667 45.7267 6.3333 2.4067 28.87 10.97
38 x 125 4750 618.4896 57.1583 9.8958 3.0083 36.08 10.97
38 x 150 5700 1068.7500 68.5900 14.2500 3.6100 43.30 10.97
38 x 175 6650 1697.1354 80.0217 19.3958 4.2117 50.52 10.97
38 x 200 7600 2533.3333 91.4533 25.3333 4.8133 57.74 10.97
50 x 50 2500 52.0833 52.0833 2.0833 2.0833 14.43 14.43
50 x 63 3150 104.1863 65.6250 3.3075 2.6250 18.19 14.43
50 x 75 3750 175.7813 78.1250 4.6875 3.1250 21.65 14.43
50 x 100 5000 416.6667 104.1667 8.3333 4.1667 28.87 14.43
50 x 125 6250 813.8021 130.2083 13.0208 5.2083 36.08 14.43
50 x 150 7500 1406.2500 156.2500 18.7500 6.2500 43.30 14.43
50 x 175 8750 2233.0729 182.2917 25.5208 7.2917 50.52 14.43
50 x 200 10000 3333.3333 208.3333 33.3333 8.3333 57.74 14.43
63 x 63 3969 131.2747 131.2747 4.1675 4.1675 18.19 18.19
63 x 75 4725 221.4844 156.2794 5.9063 4.9613 21.65 18.19
63 x 100 6300 525.0000 208.3725 10.5000 6.6150 28.87 18.19
63 x 125 7875 1025.3906 260.4656 16.4063 8.2688 36.08 18.19
63 x 150 9450 1771.8750 312.5586 23.6250 9.9225 43.30 18.19
© STANDARDS MALAYSIA 2015 - All rights reserved 43
63 x 175 11025 2813.6719 364.6519 32.1563 11.5765 50.52 18.19
63 x 200 12600 4200.0000 416.7450 42.0000 13.2300 57.74 18.19
75 x 75 5625 263.6719 263.6719 7.0313 7.0313 21.65 21.65
75 x 100 7500 625.0000 351.5625 12.5000 9.3750 28.87 21.65
75 x 125 9375 1220.7031 439.4531 19.5313 11.7188 36.08 21.65
75 x 150 11250 2109.3750 527.3438 28.1250 14.0625 43.30 21.65
75 x 175 13125 3349.6094 615.2344 38.2813 16.4063 50.52 21.65
75 x 200 15000 5000.0000 703.1250 50.0000 18.7500 57.74 21.65
100 x 100 10000 833.3333 833.3333 16.6667 16.6667 28.87 28.87
100 x 125 12500 1627.6042 1041.6667 26.0417 20.8333 36.08 28.87
100 x 150 15000 2812.5000 1250.0000 37.5000 25.0000 43.30 28.87
100 x 175 17500 4466.1458 1458.3333 51.0417 29.1667 50.52 28.87
100 x 200 20000 6666.6667 1666.6667 66.6667 33.3333 57.74 28.87
125 x 125 15625 2034.5052 2034.5052 32.5521 32.5521 36.08 36.08
125 x 150 18750 3515.6250 2441.4063 46.8750 39.0625 43.30 36.08
125 x 175 21875 5582.6823 2848.3073 63.8021 45.5729 50.52 36.08
125 x 200 25000 8333.3333 3255.2083 83.3333 52.0833 57.74 36.08
150 x 150 22500 4218.7500 4218.7500 56.2500 56.2500 43.30 43.30
150 x 175 26250 6699.2188 4921.8750 76.5625 65.6250 50.52 43.30
150 x 200 30000 10000.0000 5625.0000 100.0000 75.0000 57.74 43.30
175 x 175 30625 7815.7552 7815.7552 89.3229 89.3229 50.52 50.52
175 x 200 35000 11666.6667 8932.2917 116.6667 102.0833 57.74 50.52
200 x 200 40000 13333.3333 13333.3333 133.3333 13.33333 57.74 57.74
NOTE. Any size above 150 mm shall be checked for availability.
44 © STANDARDS MALAYSIA 2015 - All rights reserved
y
x x
y
Table A3.Geometrical properties of sawn timber at 19% moisture content
Nominal size
Area Second moment of area Section modulus Radius of gyration
X-X Y-Y X-X Y-Y X-X Y-Y
mm x mm Mm2 (x10
4)mm
4 (x10
4)mm
4 (x10
4)mm
3 (x10
4)mm
3 mm mm
25 x 25 625 3.2552 3.2552 0.2604 0.2604 7.22 7.22
25 x 38 950 11.4317 4.9479 0.6016 0.3958 10.97 7.22
25 x 50 1250 26.0417 6.5104 1.0417 0.5208 14.43 7.22
25 x 63 1575 52.0931 8.2031 1.6538 0.6563 18.19 7.22
25 x 75 1875 87.8906 9.7656 2.3438 0.7813 21.65 7.22
25 x 100 2500 208.3333 13.0208 4.1667 1.0417 28.87 7.22
25 x 125 3125 406.9010 16.2760 6.5104 1.3021 36.08 7.22
25 x 150 3750 703.1250 19.5313 9.375 1.5625 43.30 7.22
25 x 175 4375 1116.5365 22.7865 12.7604 1.8229 50.52 7.22
25 x 200 5000 1666.6667 26.0417 16.6667 2.0833 57.74 7.22
38 x 38 1444 17.3761 17.3761 0.9145 0.9145 10.97 10.97
38 x 50 1900 39.5833 22.8633 1.5833 1.2033 14.43 10.97
38 x 63 2394 79.1816 28.8078 2.5137 1.5162 18.19 10.97
38 x 75 2850 133.5938 34.2950 3.5625 1.8050 21.65 10.97
38 x 100 3800 316.6667 45.7267 6.3333 2.4067 28.87 10.97
38 x 125 4750 618.4896 57.1583 9.8958 3.0083 36.08 10.97
38 x 150 5700 1068.7500 68.5900 14.2500 3.6100 43.30 10.97
38 x 175 6650 1697.1354 80.0217 19.3958 4.2117 50.52 10.97
38 x 200 7600 2533.3333 91.4533 25.3333 4.8133 57.74 10.97
50 x 50 2500 52.0833 52.0833 2.0833 2.0833 14.43 14.43
50 x 63 3150 104.1863 65.6250 3.3075 2.6250 18.19 14.43
50 x 75 3750 175.7813 78.1250 4.6875 3.1250 21.65 14.43
50 x 100 5000 416.6667 104.1667 8.3333 4.1667 28.87 14.43
50 x 125 6250 813.8021 130.2083 13.0208 5.2083 36.08 14.43
50 x 150 7500 1406.2500 156.2500 18.7500 6.2500 43.30 14.43
50 x 175 8750 2233.0729 182.2917 25.5208 7.2917 50.52 14.43
50 x 200 10000 3333.3333 208.3333 33.3333 8.3333 57.74 14.43
63 x 63 3969 131.2747 131.2747 4.1675 4.1675 18.19 18.19
63 x 75 4725 221.4844 156.2794 5.9063 4.9613 21.65 18.19
63 x 100 6300 525.0000 208.3725 10.5000 6.6150 28.87 18.19
63 x 125 7875 1025.3906 260.4656 16.4063 8.2688 36.08 18.19
63 x 150 9450 1771.8750 312.5586 23.6250 9.9225 43.30 18.19
63 x 175 11025 2813.6719 364.6519 32.1563 11.5765 50.52 18.19
© STANDARDS MALAYSIA 2015 - All rights reserved 45
63 x 200 12600 4200.0000 416.7450 42.0000 13.2300 57.74 18.19
75 x 75 5625 263.6719 263.6719 7.0313 7.0313 21.65 21.65
75 x 100 7500 625.0000 351.5625 12.5000 9.3750 28.87 21.65
75 x 125 9375 1220.7031 439.4531 19.5313 11.7188 36.08 21.65
75 x 150 11250 2109.3750 527.3438 28.1250 14.0625 43.30 21.65
75 x 175 13125 3349.6094 615.2344 38.2813 16.4063 50.52 21.65
75 x 200 15000 5000.0000 703.1250 50.0000 18.7500 57.74 21.65
100 x 100 10000 833.3333 833.3333 16.6667 16.6667 28.87 28.87
100 x 125 12500 1627.6042 1041.6667 26.0417 20.8333 36.08 28.87
100 x 150 15000 2812.5000 1250.0000 37.5000 25.0000 43.30 28.87
100 x 175 17500 4466.1458 1458.3333 51.0417 29.1667 50.52 28.87
100 x 200 20000 6666.6667 1666.6667 66.6667 33.3333 57.74 28.87
125 x 125 15625 2034.5052 2034.5052 32.5521 32.5521 36.08 36.08
125 x 150 18750 3515.6250 2441.4063 46.8750 39.0625 43.30 36.08
125 x 175 21875 5582.6823 2848.3073 63.8021 45.5729 50.52 36.08
125 x 200 25000 8333.3333 3255.2083 83.3333 52.0833 57.74 36.08
150 x 150 22500 4218.7500 4218.7500 56.2500 56.2500 43.30 43.30
150 x 175 26250 6699.2188 4921.8750 76.5625 65.6250 50.52 43.30
150 x 200 30000 10000.0000 5625.0000 100.0000 75.0000 57.74 43.30
175 x 175 30625 7815.7552 7815.7552 89.3229 89.3229 50.52 50.52
175 x 200 35000 11666.6667 8932.2917 116.6667 102.0833 57.74 50.52
200 x 200 40000 13333.3333 13333.3333 133.3333 13.33333 57.74 57.74
NOTE. Any size above 150 mm shall be checked for availability.
46 © STANDARDS MALAYSIA 2015 - All rights reserved
Annex B (Normative)
Modification factor for compression members
The value of the modification factor K8 for compression members with slenderness ratios
equal to or greater than 5 is given by the equation :
1 (1+ )2 E 1 (1+ )
2E
2
2 E
1/2
K8 = + - + -
2 2N2
c 2 2N2
c N2
c
where,
c is the compression parallel to the grain stress for the particular conditions of loading
(see 12.5);
E is the appropriate modulus of elasticity for the particular exposure condition (see
12.5);
is the slenderness ratio , i.e. the effective column length divided by the radius of
gyration (Le/i);
is the eccentricity factor (taken as 0.005 in deriving the values given in Table 10);
and
N is the reduction factor used to derive grade compression stresses and moduli of
elasticity and, in this case, has the value 1.5.
For the specific purposes of calculating K8, the minimum value of E (modified if applicable by
K7 or K18 of MS 544 : Part 3, see 8.5) should be used and c should not include any
allowance, for load sharing.
For compression members acting alone, the permissible stress is :
c, adm = K8 c
For compression members in load-sharing systems (see Clause 10), the permissible stress is:
c, adm = 1.1K8 c
© STANDARDS MALAYSIA 2015 - All rights reserved 47
Bibliography [1] BS EN 384: 1995, Structural Timber – Determination of characteristic values of mechanical properties and density [2] BS 6100, Glossary of building and civil engineering terms [3] AS 1720.1-1998, Timber structures code - Part 1: Design methods [4] AS 1720-1975, Timber engineering code [5] Malaysian Grading Rules for Sawn Hardwood Timber 1984 (Ed), MTIB. [6] Timber Design Handbook. Malayan Forest Records No. 42. 1997, FRIM.
48 © STANDARDS MALAYSIA 2015 - All rights reserved
Acknowledgements Members of Technical Committee on Timber structures Prof Dr Zakiah Ahmad (Chairman) University Teknologi Mara Ms Syafinaz Abd Rashad (Secretary) Malaysian Timber Industry Board Mr Mohd Idrus Din Construction Industry Development Board Malaysia Dr Tan Yu Eng Forest Research Institute Malaysia Ir Lai Sze Ching Institute of Engineers Malaysia Ar. Chris Yap Seng Chye Malaysian Institute of Architects Ms Hamidah Abdullah Malaysian Timber Council Mr Muhammad Shaiful Nordin Malaysian Timber Industry Board Ir. Ahmad Redza bin Ghulam Rasool Ministry of Urban Wellbeing, Housing & Local
Government Mr Ng Wun Pin Multinail Asia Sdn Bhd Ir Azman Jamrus Public Works Department Mr Nicholas Andrew Lissem Sarawak Timber Industry Development Corporation Mr Lee Leh Yew Timber Exporters’ Association of Malaysia Assoc Prof Dr H’ng Paik San Assoc Prof Dr Badorul Hisham Abu Bakar
Universiti Putra Malaysia Universiti Sains Malaysia
Assoc Prof Dr Abd Latif Saleh Universiti Teknologi Malaysia Assoc Prof Dr Mohd Ariff Jamaluddin Universiti Teknologi Mara Assoc Prof Dr David Yeoh Eng Chuan Universiti Tun Hussein Onn Malaysia Mr Mohd Nor Zamri Mat Amin Wood Industry Skills Development Centre Members of Working Groups on MS 544 Part 1
Assoc. Prof. Dr Zakiah Ahmad (Chairman) Universiti Teknologi MARA Ms Syafinaz Abd Rashad (Secretary) Malaysian Timber Industry Board Dr. Mohd Omar Mohd Khaidzir Forest Research Institute Malaysia Mohammad Shaiful Nordin Malaysian Timber Industry Board Mr Ng Wun Pin Multinail Asia Sdn Bhd Ir Azman Jamrus/ Public Works Department Ms Mimi Suriyani Ismail Mr Nicholas Andrew Lissem Sarawak Timber Industry Development Corporation Prof Dr. Badorul Hisham Abu Bakar Universiti Sains Malaysia Assoc. Prof. Dr Abd Latif Saleh Universiti Teknologi Malaysia Assoc. Prof. Dr Mohd Ariff Jamaludin Universiti Teknologi MARA Dr David Yeoh Eng Chuan Universiti Tun Hussein Onn Malaysia