Preserving our past Commissioner’s House verandah restoration maintains the original aesthetic and conserves its historic value
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ommissioner’s House dominates the Dockyard skyline and since it was built two hundred years ago, has become an icon of the West End. However, with its location exposed to the harsh Bermuda elements, the building requires constant care and conservation. Most recently, the dark red columns, hand railing and concrete floor of the wrap around verandah have all been repaired or replaced. “The reason the floor needed rebuilding”, says Michael Tatem of contractor Crisson Construction, “was that the existing verandah was a precast system of concreate slabs that were laid in between steel beams. They were 34
about four inches thick and were prestressed. When they manufacture these in the factory, they have reinforcing wire running through the slab. And then they cut the slab to the size you want, and the wire that’s prestressed in slab is exposed at the end.” “What should have happened when the building was restored in the 1990’s”, explains Tatem, “is the end of the slab needed to be sealed where the rebar sticks out, otherwise it rusts.” Although a four-inch topping slab was put over the pre-cast slab, over a period of time, rainwater ingressed through that slab into the precast slabs and rusted the rebars that were prestressed.
When rebar rusts, it expands and the concrete falls away. This was happening at Commissioner’s House, it was becoming unsafe, and big pieces were dropping away. Tatem says the four-inch slabs were jackhammered off the top, and then the pre-cast slabs were removed, all the way around the verandah. “Once all the concrete was removed, the supporting steel beams were exposed. We then removed the rubber membrane from the steel beams and had them sandblasted. The handrails and columns were sandblasted at the same time. Then a 3-part paint system was used — primer, rust proofing and topcoat.” On inspection of the exposed steel beams, Crisson Construction found that some of the connections were not supported properly. Tatum points out that “the engineer had to redesign some of those connections. Each one of those BUILDINGBERMUDA2023
