Engineering Investigation and Restoration of Exterior
Walls and Roofs of Old Post Office Building
(1884 Truro Federal Building) 695 Prince Street, Truro, Nova Scotia
Owner and Client: Town of Truro, Truro, Nova Scotia
Scope of Consulting Services Included the Following:
- Investigated exterior masonry walls and roofs.
- Reported to Owner/Client throughout the various phases of restoration construction.
- Prepared restoration design drawings and specifications for phased tendering.
- Provided project management services during restoration construction, including administration of the Contracts between the Owner and the Contractors throughout the various phases of the restoration construction.
- Provided on-site inspection and documentation during restoration construction and issued design details to restore concealed defects, etc.
- 2012-01: Front (South) elevation of the Old Post Office Building (Truro Federal Building).
Photograph taken while building was occupied as a school and prior to the Cowie restoration construction of the main three-storey building.
- 2012.02: South and West elevations.
The photograph was taken while the building was occupied as a school and prior to the Cowie restoration construction of the main three-storey building.
- 2012.03: Plaque describing history of the building.
Prior to the Cowie restoration, a band of sandstone between the first and second floors on the front elevation was covered with stucco (2012.01)
- 2012.04: Stone arch window opening of the third floor and upper portion of South gable end of the building.
The brickwork was cracked and bulged, and the stone arch was spreading.
- 2012.05: View along the South (front) gable wall.
Shows the wall bulged outward.
- 2012.06: Top portion of the South gable wall with diamond pointed cut sandstone units.
- 2012.07: East elevation of the building prior to the Cowie restoration while the building was occupied as a school.
- 2012.08: Example of past repair efforts to resolve roof water leaks.
Photo of copper sheet roofing and slate.
- 2012.09: Northeast corner of the North annex to the main three-storey building.
The building was occupied as a school.
- 2012.10: Back (North) elevation of the main three-storey building prior to the Cowie restoration.
The building was occupied as a school.
- 2012.11: Job sign at the commencement of the restoration construction.
At the commencement of the restoration construction, the building was occupied as a school.
- 2012.12: Access scaffolding extending across the front (South) elevation and along the East and West elevations of the main three-storey building.
- 2012.13: Outer wythe of brickwork removed around the third floor central stone masonry arch window of the South gable wall.
- 2012.14: Installed reinforcing steel for construction of the reinforced concrete wall beam to prevent further spreading of the arch and the outward bulging of the South gable wall.
- 2012.15: Reinforced concrete wall beam surrounding the South gable central arch.
- 2012.16: Reconstruction of the masonry wall of the South gable above the third floor central arch window.
- 2012.17: Reinstallation of diamond pointed cut sandstone units with reinforced concrete block masonry back-up wall at the top portion of the South gable wall.
- 2012.18: Third floor and attic portion of the West gable wall. The brickwork was cracked and bulged and the sandstone capstones were shifted.
- 2012.19: Sandstone capstones removed revealing deteriorated clay brick masonry wall construction.
- 2012.20: Additional capstones removed from the West gable wall revealing deteriorated clay brick masonry construction.
- 2012.21: Outer wythe of brickwork of West gable removed revealing the deteriorated condition of the remaining brickwork construction.
West gable wall above the third floor.
- 2012.22: Outer wythe of brickwork removed from West gable wall above third floor.
Lime/sand mortar had lost all bond strength, and brickwork had lost all structural integrity. Numerous bricks deteriorated from freeze-thaw action.
- 2012.23: Example of extensive wood rot within the roof framing in the valley area at the bearing wall support.
- 2012.24: Rebuilt timber framed construction shown in photo 2012.23.
- 2012.25: Reconstruction of the roof soffit at the third floor area of the South elevation.
- 2012.26: Reconstructed third-floor knee wall and roof framing.
- 2012.27: East and North elevations of the North annex to the main three-storey building while the building was occupied as a school. Viewing Southwest.
- 2012.28: Existing masonry wall construction along East wall of North annex (see photo 2012.27).
Lime/sand mortar had lost all bond strength - bricks had shifted, and clay bricks could be easily removed by hand.
- 2012.29: Outer wythes of clay bricks removed from East & North elevation of North annex.
Brickwork was extensively deteriorated, and timber roof construction rotten. Original timber roof sloped down from East to West.
- 2012.30: North elevation at Northeast corner of North annex.
Shows original (1884) roof sloping down from East to West.
- 2012.31: Wood rot within original (1884) timber roof construction (see photo 2012.30).
- 2012.32: Deteriorated brickwork throughout the North wall of the North annex. Shows the original timber lintel above the window opening.
- 2012.33: Deteriorated brickwork in Northwest corner of North annex. Inner wythes of brickwork were in advanced state of deterioration and beyond repair.
Outer wythes of brickwork were installed during the 1950's.
- 2012.34: South & East elevations of main 3-storey building with original masonry walls & roofs of 1884 North annex replaced with new steel-framed construction (Jan.2002).
Building vacant, but to be re-occupied by school upon completion of restoration.
- 2012.35: North & West elevations of the main building, w. North annex ext. walls demolished.
New steel-framed construction w. a flat roof covered remaining timber roof of North annex - to remain in place if school re-occupied building.
- 2012.36: North & East elevations of brick masonry chimney.
Extended in height,as revealed by colours of brickwork, it was cracked throughout and the mortar was in advanced deterioration from exfiltration of chimney flue gases. Chimney had no liner.
- 2012.37: Section of original (1884) chimney construction and ease in which bricks were removed.
Deterioration was beyond repair & chimney was demolished and replaced with brick masonry chimney w. insulated stainless steel flue.
- 2012.38: New brick masonry construction with 10-inch diameter insulated stainless steel flue.
- 2012.39: Reinforced concrete chimney cap on the brick masonry chimney.
Shows the insulated stainless steel flue extending through the chimney cap.
- 2012.40: New chimney construction.
- 2012.41: Central North/South sloped roof w. new sheet copper cap & flashings installed on roof edge.
Original slate shingles removed, roof deck restored & covered w. waterproofing membrane and ready for instalation of new slate shingles.
- 2012.42: Example of instalation of new slate shingles.
- 2012.43: Original North elevation louvre to vent attic.
The wood had deteriorated beyond economical repair.
- 2012.44: New wood louvre made to match the existing wood louvre shown in photo 2012.43.
- 2012.45: New sheet copper caps, sheet copper flashings & new slate shingles.
New copper work and slate shingles installed by Heather & Little Ltd. of Toronto.
- 2012.46: New slate shingles & new copper caps and flashings.
- 2012.47: Top of East gable at intersection w. East/West roof ridge w. new sheet copper caps and flashings.
- 2012.48: New sheet copper on walls and roof of the dormer and new slate shingles.
- 2012.49: Example of new copper gutter, new slate shingles & new electric heat tracing.
- 2012.50: New copper gutter showing instalation of copper mesh screening to prevent the entry of leaves, etc.
- 2012.51: New wood fascia & new copper gutters.
- 2012.52: Example of underside of vented soffit (see photo 2012.51).
- 2012.54: East & North
- 2012.56: Typical example of large notches cut in the timber floor joists to permit installation of heating pipes.
- 2012.58: Shows the installation of a new steel shelf angle for support of the restored timber floor joists.
- 2012.59: Example of strengthened timber floor construction supported along exterior wall by new steel shelf angles anchored to the new continuous reinforced concrete spandrel beam.
Scope of Restoration Design Included the Following:
(A) Three-Storey Main Building:
1. Restoration of Exterior Brick Masonry Walls with Dimension Sandstone Elements:
- Demolished approximately 40 percent of the brick masonry wall construction and replaced with new brick masonry wall construction to match the appearance of the original masonry wall construction. Portions of the inner wythe of the wall construction were strengthened by reinforced masonry and reinforced concrete.
- Removed and reinstalled cut stone elements.
- Repaired and anchored cut stone elements.
- Repointed and replaced brick masonry to match original 1884 construction.
- Installed new stainless steel restoration ties for connection of brick masonry wythes.
- Anchored the exterior masonry walls to the timber roof framing, third floor timber framing, and second floor timber framing.
- Installed a continuous reinforced concrete spandrel beam within the exterior masonry walls. The spandrel beam extended around the perimeter of the second floor and third floor. The reinforced concrete spandrel beam provided tensile strength to the masonry walls to prevent further spreading as well as a new support for the restored timber floor joists.
- Removed defective timber construction (rotten, split and severely distorted) and replaced with new timber framing.
- Strengthened the existing timber framing and connections.
- Removed the existing slate shingles and replaced with new slate shingles.
- Replaced and/or restored portions of the timber roof deck and installed a new waterproofing membrane.
- Removed existing defective gutters and replaced with new copper gutters, new collector boxes and new rainwater leaders.
3. Timber Floor Framing:
- Attic Floor: New timber framing installed to enable the central portion of the attic floor to safely support a live load of 100 lbs/ft2 when used as a mechanical room for support of the new HVAC equipment.
- Second Floor and Third Floor: Strengthened existing timber floor joists and, where necessary, installed new timber floor joists. The bearing ends located at the exterior walls are supported by a continuous steel shelf angle anchored to the new continuous reinforced concrete spandrel beam.
4. New Windows:
- Stipulated lump-sum tenders were called for the installation of new windows throughout the main three-storey building. The new windows were installed and all deficiencies corrected by Spring 2003.
(B) North Annex:
Portions of the North annex were of the original 1884 construction. Subsequent to the initial construction, the Federal Government of Canada and the Town of Truro added portions to the building as well as modified portions of the 1884 construction.
The original 1884 construction of the North annex consisted of two wings extending from the North face of the building with each wing having a pitched roof. Subsequent to the initial construction, the courtyard/loading area between the two North wings of the North annex was infilled with new construction changing the North annex to rectangular shape in plan with flat roofs.
Cowie investigated the exterior masonry walls and roofs. The Cowie investigation revealed the exterior brick masonry walls were in an advanced state of deterioration and beyond repair. Portions of the 1884 timber roof construction and the 1884 timber floor construction were rotten. Sections of the modified roof construction were also found to be rotten. During the Cowie restoration, the exterior brick masonry walls, portions of the timber roof construction, and a portion of the first floor timber framing were demolished.
Restoration Construction of North Annex:
New Steel Frame Over Existing Roof Construction For School Occupancy:
- A new steel frame with flat roof was installed over the existing timber-framed construction. The steel columns located within the interior of the North annex were relocated to maintain the original layout of the school occupancy, and the steel framing within the exterior wall construction was located to maintain the same window locations for reoccupancy by the school.
- After construction of the one-storey steel framed flat roof of the North annex, it was decided the school would not be reoccupying the building and the building was to be renovated for office occupancy.
Preparation of Design Drawings & Specifications for Town of Truro Office Occupancy:
- Cowie Engineering prepared restoration design drawings and specifications to restore the interior of the main three-storey building, including installation of a new elevator plus a new two-storey North annex. The space planning for the building was for office occupancy by the Town of Truro. Tenders were called for stipulated lump-sum pricing. The Town of Truro did not accept the tendered prices and did not wish to reduce the scope of the restoration construction and re-tender in the hope of obtaining lower lump-sum stipulated prices.