100 Bentley Street
The client preferred a system based on the previous membrane that would provide reliable longevity to the roof and class A fire protection, so we chose a 4 ply built-up roof consisting of 1 ply #15 perforated felt paper plus 3 plies of type 4 glass felt paper, an asphalt flood coat and ⅜” pea gravel to meet those needs.
As pictured below, this roof had abandoned equipment throughout the warehouse area. The Markham building was vacant when we commenced our work. The previous tenant was in the printing business utilizing equipment for large screen and digital printing with numerous roof penetrations for exhaust. This necessitated significant patching of the steel deck throughout the warehouse areas. We coordinated the disconnection, craning off and removal of numerous redundant HVAC equipment including a large make-up air unit and a large HVAC unit and related gas piping with the client’s HVAC and craning contractors.
We also addressed another issue that dated back to the original construction. The top of the parapet walls were both 12” to 14” wide and dead flat. This situation caused leaks at the metal locks around the perimeter as evidenced by the caulking sealant we found liberally applied to numerous joints on the metal copings. This issue also allowed water to runoff over the outside walls staining the light coloured precast panels. We supplied and installed sloped wood blocking to the inside of the roof to correct this problem.
Here we see a flat top of parapet surface that has standing water. In the image below, the parapet walls have been sloped in order to avoid this problem and maintain the integrity of this 4 ply built-up roof system.
After the repair, the parapet walls have been sloped in order to avoid ponding water and maintain the integrity of this roofing system.
Many clients are unaware of the importance of both eliminating redundant roof penetrations and sloping the top of the parapet walls as part of a roof replacement project.
Type of Project: Full Roof Replacement
Roof area: 49,280 square feet.
Deck Type: Steel
Roof Membrane (field area): 1 ply #15 perforated organic felt paper plus 3 plies type 4 glass felt paper mopped in hot asphalt, asphalt flood coat and ⅜” pea gravel
Flashing Membrane (perimeter and roof upturns): 2-ply SBS modified bitumen
Insulation: 1.5″ ISO mechanically fastened to the steel deck substrate, 0.5″ perlite insulation applied in hot asphalt
Vapour retardant: reinforced kraft paper applied in adhesive
Contact Elite Roofing for your next roofing project!
If you’re experiencing ponding water issues or have a recent vacancy and want a roof assessment to provide an estimate to restore the roof to base building condition, and want to know more about how we can help, visit our contact page. We’re available through live chat during working hours and by email 24/7. That’s the Elite Advantage.