Tall Walls Slides

7/29/2019 Tall Walls Slides

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Renee Strand, P.E.

iLevelbyWe erhaeuser

July 2010NR

WoodWorks is a Registered Provider with the American Institute of

rc tects ontnu ng ucat on ystems. re t earne on

completion of this program will be reported to CES Records for AIA

members. Certificates of Completion for non-AIA members are

ava a e on request.

This ro ram is re istered with the AIA/CES for continuin

professional education. As such, it does not include content that may

be deemed or construed to be an approval or endorsement by the

AIA of an material of construction or an method or manner of

handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will be

.

Tall Wall A lications

Challenges

Products

es gn ons erat ons

Framing Details

Fire Assemblies

Innovative Solutions

Residential Construction

Foyers

Great Rooms


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Light-Framed Commercial

oo ons ruc on Schools

urc es

Retail

Multi-Family

Large Openings

Maintain in-plane shear path Maintaining Height to Width Ratio of Shear Walls

ut-o - ane e ection Protect finishes / keep building envelope in tacked

o u o Hinge points

Bracing

ualit of material

In-Plane Shear Transfer

Maximum Shear Wall

Dimension Ratios Table2305.3.4 (2006 IBC)

Wood Structural Panels

h

. : or ot er t an seismic

2:1 for seismic

3.5:1 for seismic if allowablew

shear multiplied by 2w/h

In-Plane Shear Transfer

Pre-fabricated Shear Walls

Allowable In-Plane

550 lbs to 1460 lbs

seismic control

605 lbs to 2445 lbswind control


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Excessive Deflection

-- --

Walls dont feel stiff Performance issues

Moisture intrusion

Exterior/Interior finish

cracks and pops

IBC Table 1604.3

-- --

Flexible Finishes: H/120 (2009 IBC H/180)

Brittle Finishes: H/240

The wind load is permitted to be taken as 0.70 times

the com onent and claddin loads for the ur ose

of determining deflection limits

IBC Section 2403.3

Mullions: L/175 up to "

. Plaster/Stucco Surfaces: H/360

Not Straight Bowing, twisting and warping

of solid-sawn lumber

Limited Material Len ths Hinge Point creates a structural weakness in

the wall


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Engineered Lumber Products

Code Evaluation Reports AC202 Acceptance Criteria for Wood-Based Studs

.

Ex.: 6.2 Data in accordance with the ICC-ES

Acceptance Criteria for Wood-based Studs (AC202),

.

Desi n ConsiderationsDesi n Considerations

Combined Loads Vertical Load

Vertical Load Roof/Snow and dead

atera oa

Wind load ( to wall plane)

Wind and Seismic // to wall lane Pressure

Deflection

rmWindD

eflectio

Unif

Vertical Load

Stud or Column

Uniform Wind Pressure

Top View of Wall Header

Buckling Height Limits Every column has a height limit to prevent buckling

Max height = 50d (d= depth in inches)

3(2x4) Max Height: 143(2x4) Max Height: 14

between blockingbetween blocking

x ax eg :x ax e g : --

7(2x8) Max Height: 307(2x8) Max Height: 30

Stud or column in a sheathed Stud or column in a sheathed

wall is braced against

buckling in this direction.

wall is not braced against

buckling in this direction.

National Design Specification (NDS)

Eqn 15.4-10

Eqn 3.7-1

E n 15.3-1 multi le C b K for built-u

columns


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no a onsCP

c = 0.9 for SCL and GLB

c = 0.8 for sawn lumber

no a onsCP

FcE = 0.822 Emin/(le/d)2

= - -min . . .

E = Eapparent

e = . to . Ke = 0.85 to 1.0 to determine le

Allowable Design Stresses

Design

StressesDFL#2 SP#2 ES11 ES12 LSL 24F LVL PSL

Fb psi 900 1250 1350 19501700to

24002250to

2900

Ex106 psi 1.6 1.6 1.6 1.9 1.3to1.6 1.6 1.5to2.0 2.0

Fv psi 95 90 200 200400to

410 190

250to290 290

Fc//psi 1350 16001350to

1550

1700to2300

1400to2175

16502350to

32002900

notations

e = eccentricity

1/6 of the wall thickness1/

6w

w


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Exposure B

Exposure C Exposure D


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Nailin

Spacing

Lateral and withdrawal valuesDependent on specific gravity of product

Specific gravity varies between face and edge

Hold-downs

Bolt values

screws

Multiple Resources for Fire-rated

assemblies

Solid Sawn IBC

G sum Association GA-600-2009

www.gypsum.org

American Wood Council Desi n for Code

Acceptance 3

www.awc.org

Finger-Jointed Stud

HRA mark required


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ELP

Check manufacturers code evaluation reportMay be a direct substitute in sawn lumber

assemblies

May be reduction to allowable design stresses

ay nee a t ona nsu at on

Fire Retardant Treatments

LSL, LVL, PSL check with the manufacturerMost dont allow voids warranty

Glue-laminated members check with manufacturer

Not recommended

Lumber

Allowed

Design Value Reductions 0.80 to 0.98 Galvanized or stainless steel fasteners reductions

apply 0.91 to 0.98

Tilt-up LSL wall

I-Joists as wall studs?

Advantages

Reduced ca acit for thermal brid in

Thicker walls / More insulation

Not code evaluated

-

Special detailing required


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Th k Yh k Yhank Youhank You

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