695 Prince Street – Truro, Nova Scotia
Engineering investigation and restoration of exterior
walls and roofs of the 1884 Truro Federal Building.
Owner and Client: Town of Truro
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.
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.