Structural Survey and Dilapidations - tipperarycoco.ie · 1. Introduction 2. Scope 3. Description...
Transcript of Structural Survey and Dilapidations - tipperarycoco.ie · 1. Introduction 2. Scope 3. Description...
Emmet Place Carpark Nenagh
Structural Survey and Dilapidations
Mitchel Street
Nenagh
Co. Tipperary
EDPM Consulting Engineers
May 2019
Emmet Place Carpark Nenagh
Contents
1. Introduction
2. Scope
3. Description of Existing Structure
4. Schedule of Dilapidations
5. Demolitions
6. Proposed Works
7. Photographs
Appendix A – photograph reference
Appendix B – OSI historic mapping
Emmet Place Carpark Nenagh
1. Introduction
This report was prepared at the request of Roadplan Consulting Engineers. An inspection of the properties took place on the 8th of May 2019. Access to the properties was arranged through the County Council. The owner of the property known as the ‘House of Gifts’ was present during the inspection of that building and aided access to all areas. Also present was PJ Brett, Consulting Engineer acting on behalf of the owner of the ‘House of Gifts’ and MJ Walsh of Roadplan Consulting Engineers. Please note that this report is based on a visual inspection only and cannot take into account any items, which were covered up or inaccessible during the inspection. The report therefore, cannot be construed to guarantee a soundly constructed dwelling free from flaws and defects other than those noted. A reasonable attempt was made to access all parts of the building both internally and externally. Where details or materials were hidden, assessments were based on their likely condition according to the surrounding building details observed. Foundations have not been assessed by trial holes, but from observation of the condition of the walls and structure above them. The report does not guarantee the standards of the building elements. Specialist services tests have not been carried out, for example, water purity, heating and electrical systems, security systems, air tightness of external drains, radon gas. This report is for the benefit of the client only and no responsibility can be accepted to any third party without the written consent of the report writer. Left and right directions are taken facing the front of the building on Michael Street.
Emmet Place Carpark Nenagh
2. Scope
The scope of this report is as follows:
Inspect the building and describe the structures
Provide a schedule of dilapidations for the building known as the ‘House of Gifts’
Provide recommendations in relation to any demolitions
Provide recommendations on stability works to remaining structures The inspections and report were carried out and prepared under the following guidelines:
Appraisal of existing structures (2nd edition) Institution of Structural Engineers
Guide to Surveys and inspections of buildings and associated structures Institution of Structural Engineers
BRE Digest 251 Assessment of damage in low-rise buildings
Emmet Place Carpark Nenagh
3. Description of Existing Structures
There are a number of planning applications relating to the existing buildings to alter and extend same, these were lodged and granted in the early 2000’s and some are available to view on line. The open space to the rear has a withdrawn planning application (07520013), a drawing from the on line file indicates there were existing derelict structures on that site, which have since been demolished. Map 7.1 of the Nenagh Town and Environs Development Plan 2013 – 2019 shows the site within an Architectural Conservation Area. The structures subject of this report are not on the Protected Structures list (Appendix 5 Dev. Plan). OSI historic mapping shows buildings on site from 1837, and give no indication of what was built first. The deposition of the structures to each property is roughly similar. The external walls are masonry c.600 - 700mm thick in places with party walls similar. The ground floors are concrete and anecdotal information suggests there are no basements. The upper floors to all buildings are suspended timber floors. Internal walls are a mixture of timber partitions and masonry. The vast majority of internal surfaces are drylined and/or behind display units. Buildings number 15, 16 and 17 are the retail units known as the ‘House of Gifts’. These buildings have undergone significant structural alterations to open out retail space on ground and first floor areas. The exact deposition of the structure is not readily apparent but the ceiling downstand arrangement is indicative of steel beam inserts supporting the floors and structure over. There is also a knock through in the party wall between number 15 and 16 on the ground floor connecting the retail space. The deposition of the masonry construction is visible in some locations. A window reveal to the front wall of number 15 is exposed showing brick with rubble infill, the brick construction may only be to the reveal. The rear elevation of number 18 shows a random rubble type masonry of irregular units with no coursing, a view of the gable wall of number 17 in the attic shows similar construction. The structural arrangement is simple rectangular walls on plan with the party walls providing buttressing to the front and rear walls and visa-versa. The floors may act as horizontal diaphragms tying the external walls to the internal structure, it is unlikely they transfer load to flanking party walls, albeit in a limited manner. The front and rear walls, including the exposed gable to number 20, act as vertical cantilevers tied at floor and roof level. The majority of the roofs are duo-pitched and there was limited access to attic spaces. The attic space to number 15 is a store room and the structure was not apparent but most likely a cut timber roof. The attic over numbers 16 and 17 was accessible, the structure is cut timber with raised collars and hangers supporting the ceiling joists. The ceiling is coved at the front and rear. Access to the upper floors of number 18 was not possible as the first floor is in a state of poor repair and in the writers opinion unsafe for access. Parts of the second floor ceiling to number 19 have collapsed. No attic hatch was noted in number 20. The first floor of the rear section of number 20 accessed from Emmet Place is also not fully accessible, sections of the ceiling have collapsed. The extension to the rear of 16 and 17 has flat roofs at first floor and second floor level. The second floor extension is finished with pvc cladding to all sides.
Emmet Place Carpark Nenagh
The open space to the rear was viewed from the flat roof, there is significant vegetation within and along some of the boundaries. The gable wall of number 8 Emmet Place forms part of the north eastern boundary. The balance of the boundaries are random rubble and masonry walls, the road side boundary is currently timber hoarding. The OSI mapping date back to 1837 and indicates all the structures fronting onto Mitchel Street, along with structures in the open space. Subsequent maps give no indications as to what was built when. The front elevations show the roof of 16/17 higher than that of number 18, further the rear elevations on plan are not in line. This is indicative of the buildings constructed at different times.
Emmet Place Carpark Nenagh
4. Schedule of Dilapidations
This schedule of dilapidations relates to the structure, finishes and items such as second fix carpentry have not been taken into consideration. Dilapidations were noted at the following locations:
Front elevation number 15, horizontal and inclined cracks between and above first floor window reveals (photos13, 14 and 15).
Front elevation number 15, inclined crack off right reveal first floor window
Front elevation number 15, inclined crack under cill of left second floor window
Front elevation number 16, horizontal and inclined cracking between and above central first floor windows (photo 16).
Oversailing gable of number 17, bulging and cracking at the corner with the rear elevation. The crack has opened significantly causing small sections of render to fall away, the crack continues almost vertically down the gable wall (photo 21)
Rear elevation number 15, cracking above and below window heads (photos 23 and 24).
Vertical crack over ground floor access door to number 16 (photo 22)
Internal rear wall number 15, inclined cracking over flat roof access door (photos 31 and 32)
Internal front wall number 15, cracking over second floor window heads (photos 33 and 34)
Internal wall / party wall junction number 15, horizontal crack under ceiling level (photo 35), this is a block partition supported by a timber floor.
Internal rear wall number 15, significant cracking to stairwell from first to second floor (photos 36 to 41)
Internal rear wall number 17, inclined cracking under coving line (photo 42)
Attic room number 16/17, continuous crack along rear slope coving line (photo 43)
Attic room number 16/17, crack at coving and party wall over access stairs (photo 44)
Attic space number 16/17, dislodged masonry to oversailing gable (photo 45) Some of the cracking noted is most likely a result of structural alterations at ground and first floor levels. Many of the internal walls are drylined and/or have display units, there are most likely other dilapidations behind same that are not noted from a visual inspection. Access to the upper floors of number 18 was not possible on the day of the inspection as noted above. There are dilapidations to this and number 19 and 20, however as it is the intent to demolish these buildings, they were not noted. There was no access to the rear open space, the ground floor rear elevations to numbers 15, 16 and 17 were not inspected.
Emmet Place Carpark Nenagh
5. Demolitions
It is the writers understanding that number 18, 19 and 20 are to be demolished, this includes the out buildings and structures behind number 18. These outbuildings are in a courtyard type arrangement with number 17 on two sides. Some of the structures in this area are in a very poor state and should be demolished with extreme caution (photos 17 and 18). They partially bound a small open yard which supports and oil tank and provides access to a boiler house (photo 22). There is also an access door on the ground floor of number 17 to this small yard, the proposed works may create a security issue for this yard and door. The buildings have frontage onto Mitchel Street with a 2m wide footpath. This presents an opportunity to provide hoarding and dust screens during demolition. Number 20 has dual frontage onto Emmet Place, but with no footpath. Demolition works may require a road closure. Documents from the on line planning search show there were structures in the open space, this is supported by the historic OSI maps. Any foundations or rising walls from same should be completely grubbed out to avoid ‘hard spots’ on the proposed parking area. Further, where foundations from previous structures run into the property boundaries and adjacent buildings, they should be carefully removed so as not to cause damage to the latter. The vegetation on the site boundaries should be carefully removed (photo 9). Where necessary, masonry joints may require remedial works as vegetation removal will damage same. Further, the vegetation oversails onto adjacent properties and access for local remedial works maybe required. All demolitions work should be carried out in accordance with BS 6187 : 2011 Code of Practice for Demolition, any Local Authority requirements and Health and Safety requirements. It is recommended that the demolition works and site clearance should be done by a component demolition contractor and should be specified and tendered separately from the main body of the work. The design of temporary works, including those required during demolition, would be the Demolitions Contractors responsibility. Particular attention would be brought to the temporary propping of the exposed party wall of number 17, the deposition of the permanent works will have to be taken into consideration for the design of this propping.
Emmet Place Carpark Nenagh
6. Proposed Works
From a visual inspection, it was not established if the front and rear walls of number 18 are bonded into or butted against the party wall of number 17, however the comments in section 3 should be considered. It is recommended that some pre-works opening up are done at these junctions to determine the exact deposition of the construction as this will aid the approach to the demolition and remedial works. The rear barge of the left party wall of number 17 has been structurally compromised and requires attention (photo 21). The masonry could be stitched and in places locally replaced. Similarly at the ridge the masonry is in a poor structural condition (photo 45) and should be locally rebuilt. The discolouration of the bricks suggests there was a chimney stack. It is highly likely that over time the stability of the left party wall of number 17 has become dependent upon the structure of number 18, with the front and rear walls providing buttressing to same. The intent is to demolish number 18 and some form of structure is required to maintain the integrity of the party wall. The length of the party wall is c.8m and the height from ground to eaves is 6.7m with an additional 3m to ridge. From the topographical survey, the average thickness is 720mm, slightly thicker on the ground floor. This gives a slenderness ratio of 11 which is quite stocky. There is a stairwell from ground to first floor on the number 17 side and it is highly unlikely that the wall is tied into the second floor and is not tied at roof level. After demolition, some form of buttressing is required, this could take the form of short returns off the party (now gable) wall. These should be full height but can reduce in thickness. They should be tied into the existing gable. The newly exposed gable will require weathering during and after the works. Along with temporary support works, a temporary Monarflex membrane should be applied to the exposed surface to protect the wall against the elements. The front and rear slope barges will require attention as the existing flashing is very poorly executed. New lead flashing should be applied and dressed onto the gable. This will require the removal of roof tiles immediately adjacent to the barge. The new construction should be weather tight and prevent the ingress of moisture. As noted above, lead flashing is required at the barge, flashing will also be required at all horizontal surfaces , i.e the top of all tapers. The exposed masonry should be plastered with a waterproof sand/cement render. The proposed levels to the carpark area should be above the foundation levels of the boundaries. This approach will negate the requirement for any underpinning of delicate structures.
Emmet Place Carpark Nenagh
7. Photographs
1. Building elevations to Michael Street 2. As per photo 1
3. Building elevations to Emmet Street 4. As per photo 3
5. Part rear building elevations 6. As per photo 5
Emmet Place Carpark Nenagh
7. Gable of building to NE boundary 8. Part view of the rear open space
9. Part view of SE boundary to open space 10. As per photo 8
11. Front elevation no’s 18 and 19 12. Front elevation no’s 16 and 17 part ‘House of Gifts’
Emmet Place Carpark Nenagh
13. Part front elevation no. 15 part ‘House of Gifts’ 14. As per photo 13
15. Detail of front elevation of no. 15 16. Detail of elevation of no’s 16 and 17
17. Rear area of no. 18 18. As per photo 17
Emmet Place Carpark Nenagh
19. Part rear elevation no. 18 20. Part rear elevation no’s 19 and 20
21. Bulging and cracking rear corner of no. 17 22. Vertical crack ground floor wall no. 16.
23. Part rear elevation no. 15. , note the infilled window 24. As per photo 23
Emmet Place Carpark Nenagh
25. Part view rear extension no. 16 26. Part view ground floor House of Gifts no. 16 and 17
27. Ground floor ope from no’s 16 to 15 28. Ground floor no. 15
29. Part view first floor no. 16 30. As per photo 29
Emmet Place Carpark Nenagh
31. Second floor rear wall no. 15 32. As per photo 31
33. Second floor front wall no. 15 34. Detail of the window head photo 33
35. Party wall / internal wall junction no. 15 36. Rear wall of no. 15 stairwell second floor, inside photo 23
Emmet Place Carpark Nenagh
37. Rear wall no. 15 half landing 38. Cracking to party wall no. 15/16
39. Rear wall no. 15 40. Head detail of photo 36
41 Internal second floor wall 42. Rear wall attic to no’s 16/17
Emmet Place Carpark Nenagh
43. Coving line rear pitch no. 17 44. Wall / ceiling junction party wall no. 17
45. Oversailing gable no. 16 46. Attic over no. 16
47. Part view first floor no. 18
Emmet Place Carpark Nenagh
Appendix A – Photograph Reference
54.553
54.502
54.488
54.502
54.528
54.578
54.530
54.545
54.603
54.68
4
54.681
54.452
54.405
54.429
54.443
54.470
54.495
54.510
54.471
54.425
54.454
54.480
54.523
54.554
54.555
54.866
54.873
54.918
54.855
54.845
54.855
54.878
54.901
54.913
54.929
54.942
54.963
54.865
54.8
82
54.938
54.957
54.996
55.033
55.065
55.081
55.119 55.027 55.026 55.095
55.122
55.083
55.0
70
55.0
74
54.9
96
54.9
42
54.971
54.914
54.917
54.935
54.965
54.969
54.943
54.967
55.014
55.045
AJ54.946
AJ54.869
AJ54.917
MH55.084
55.00
55.00
55.00
55.0
0
55.00
55.00
55.00
55.00
55.00
55.00
55.00
55.00
55.00
55.00
55.00
55.00
54.75
54.75
54.75
54.75
54.75
54.50
54.50
54.5
0
54.50
54.50
54.50
54.5
0
54.50
54.5
0
54.5
0
54.50
54.5
0
54.5
0
54.5
0
54.5
0
54.5
0
54.50
54.5
0
54.5
0
54.2
5
54.2
5
54.50
54.50
54.5
0
54.50
54.50
54.50
Concrete
path
Concrete
path
Concrete
path
Concrete path
59.3
38
61.947
62.031
61.141
BD
BD
Roof lvl:
61.63
Eaves lvl:
61.16Eaves lvl:
61.16
Eaves lvl:
61.13
Eaves lvl:
61.03
Eaves lvl:
61.12
Eaves lvl:
61.07
Eaves lvl:
63.50
Eaves lvl:
61.32
Eaves lvl:
63.27
Eaves lvl:
63.22
Eaves lvl:
61.93
Eaves lvl:
62.65
Eaves lvl:
61.39
Eaves lvl:
61.38
Eaves lvl:
58.49
Eaves lvl:
59.35
Eaves lvl:
59.35
Eaves lvl:
61.38
Eaves lvl:
61.12
Eaves lvl:
60.14
Eaves lvl:
60.13
Eaves lvl:
60.21
Eaves lvl:
60.21
Eaves lvl:
59.97
Eaves lvl:
59.67
Eaves lvl:
58.86
Ridge lvl:
63.97
Ridge lvl:
63.68
Ridge lvl:
64.04
Ridge lvl:
64.18
Ridge lvl:
64.22
Ridge lvl:
65.61
Ridge lvl:
66.51
Ridge lvl:
66.46
Ridge lvl:
66.28
Ridge lvl:
64.36
Ridge lvl:
64.09
Ridge lvl:
64.22
Ridge lvl:
64.28
Ridge lvl:
64.19
Ridge lvl:
62.01
Ridge lvl:
61.08
Ridge lvl:
60.62
Ridge lvl:
61.56
Ridge lvl:
62.23
Roof lvl:
57.81
Blocked doorw
ay
Mitchel S
treet (R497)
Emm
et Place
Pedestrian
access under
building
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
TE
LE
CO
M
60.3
83
Roof lvl:
58.11
Roof lvl:
58.46
Stone building ruins (taped)
Roof lvl:
61.76
Yard (t
aped)
Ridge lvl:
61.39
Eaves lvl:
59.03
Eaves lvl:
59.24
Ridge lvl:
61.62
Stone building
Stone wall
Stone wallStone wall
Stone wall
Stone wall
Stone wall
Plastered wall
Stone p
ath
(under c
onstructi
on)
Cobble path
Cobble path
Cobble
path
Cobble path
Cobble path
Cobble path
Cobble path
Cobble path
Cobble path
Area of dense overgrowth
Building lines surveyed
at first floor level
shown in Green
Building lines surveyed
at first floor level
shown in Green
Timber hoarding
Timber hoarding
Sheahan's Hom
evalue Hard
ware
Old concrete fe
eders / tro
ughs
S01
E/X: 586489.495
N/Y: 679202.918
Ht/Z: 55.085m
S02
E/X: 586520.689
N/Y: 679231.098
Ht/Z: 54.610m
Combined sewer line?
Ø450mm Concrete
MH
CL:55.16m
IL: 53.90m
Com
bin
ed se
wer lin
e?
Ø450
mm
Concre
te
Com
bin
ed s
ew
er lin
e?
?Ø
375
mm
Concre
te
IL:
53.9
3m
Ø100mm
uPVC
1
23
4
5
6
7
8
9
10
11
12
13
14
15
16
Photograph number and direction Overall Site Plan
54.767
54.744
54.772
54.722
56.344TOW:55.040
55.26055.438
55.613
54.93655.123
55.30355.503
55.69655.894
56.07756.275
56.165
55.963
55.767
55.564
55.370
55.180
54.993
55.76956.897
55.72256.782
55.44557.064
55.64657.214
55.59657.059
55.79956.572
56.5
74
55.80655.998
56.19056.382
55.16455.350
55.52355.709
55.87856.065
56.24056.415
56.59056.765
56.94057.115
57.29057.465
56.874
56.7
24
N
S
EW
N
S
EW
26
27
28
Ground Floor Plan
57.174
57.024
57.62557.780
57.93758.127
58.27858.456
58.63458.828
56.359
58.242
58.06557.867
57.67056.365
56.564
58.15759.696
58.16459.698
58.14859.619
58.13559.625
58.12059.690
58.10059.676
57.54158.712
58.30459.334
57.49658.678
59.54259.839
57.91758.606
55.35055.523
55.70955.878
56.06556.240
57.84358.004
58.17058.343
58.751
57.85258.032
58.21258.392
58.572
57.660
57.324
56.874
56.7
24
56.5
74
59.54460.475
56.41556.590
56.76556.940
57.11557.290
57.46554.936
55.12355.303
55.50355.696
55.89456.07756.275
57.88059.180
57.155
56.985
56.815
56.645
56.460
58.22759.127
56.749
56.934
57.119
57.304
N
S
EW
N
S
EW
17
18
19
20
21
22
23
24
25
29
30
31
32
47
First Floor Plan
Emmet Place Carpark Nenagh
58.502
58.6
97
58.920
59.085
59.276
59.476
59.697
59.909
60.346
61.183
61.31160.34261.097
60.27161.180
61.246
60.34261.097
60.36161.333
58.03558.204
58.38358.563
58.73858.918
59.095
60.150
59.981
59.272
61.180
61.180
61.18060.27161.246
61.18359.881
59.695
59.50859.318
59.14358.951
58.751
58.572
58.03258.212
58.392
57.838
59.44259.612
59.787
60.38061.135
60.38061.135
60.38061.135
60.38061.135
N
S
EW
N
S
EW
3334
35
36
37
3841
42
43
44
Second Floor Plan
Photograph number and direction at each floor level
Emmet Place Carpark Nenagh
Appendix B – OSI Historic Mapping
1837 – 1842 map 1888 – 1913 map