FLAT ROOFS – Lee Centre Drive, Scarborough
Lee Centre Drive, Scarborough
Flat roof waterproofing
Roof repair was required at one of the high-rise residential buildings that are connected with a shared facility. Both top and lower roof required waterproofing (total area of 4,400 SQF and 2,600 SQF, respectively).
Multiple leaks into the gym and common areas located underneath.
Localised EPDM membrane failures.
The application design proposed divided the project into two phases: top roof first and lower roof next. Each roof, in turn, had to be done in stages because of the gravel which had to be moved to the side to allow for membrane repair and waterproofing. The top roof was waterproofed in five days, and the lower roof was done in three.
Application specifications included work staging, gravel and insulation removal, existing EPDM membrane repair, application of a slow-setting cold-applied polyurea membrane, new insulation, and gravel.
The contractor was required to move half of the gravel to the other half of the roof and remove the insulation, exposing the EPDM membrane. In those locations where the membrane had cracked, or the entire area had failed, that part of the membrane had to be removed, and a non-woven polyester fleece had to be placed, overlapping the surrounding EPDM membrane. Using this fabric enhances the durability of the polyurea membrane which was to be applied next, with a roller, over the entire roof surface. Once the membrane cured, new 4” XPS Styrofoam insulation boards were to be installed, covered wit roofing filter fabric, and the gravel placed back. The process was to be repeated for the second half of the roof.