Client: Shell C-Station
Location: Ajax, Ontario
Project Scope: Complete removal of an existing ballasted EPDM roofing system and installation of a new fully adhered SBS modified bitumen roofing system, including tapered insulation, coverboard, flashings, and rooftop safety guardrails.
PROJECT OVERVIEW
The Shell C-Station in Ajax had been experiencing ongoing roof leaks caused by the aging ballasted EPDM roofing system. The existing river rock ballast, EPDM membrane, and insulation had reached the end of their service life and were no longer providing reliable waterproofing.
After evaluating the roof assembly, a full roof replacement was recommended. The project involved removing the existing roofing system down to the metal deck and installing a new high-performance modified bitumen system designed to improve drainage, durability, and long-term reliability for this active commercial property.
WORK COMPLETED
Our team completed a full tear-off and replacement, including:
- Removed the existing river rock ballast, EPDM membrane, and insulation down to the metal deck
- Installed a DensDeck board adhered with low-rise foam for added durability and protection
- Installed a fully tapered poly-iso insulation system adhered with low-rise foam to improve drainage
- Installed a composite coverboard to provide a strong and stable base for the roofing membrane
- Installed SBS modified bitumen base membrane across the roof surface
- Installed a self-adhered granulated SBS cap membrane in the roof field and at flashings
- All modified bitumen membranes supplied by the manufacturer Polyglass
- Installed a new ballasted guardrail system around the HVAC unit for safe rooftop access
- Reinstalled the existing hatch guard safety rail system
New Roofing System Installed
- DensDeck cover board adhered with low-rise foam
- Fully tapered polyisocyanurate (poly-iso) insulation system for improved drainage
- Composite coverboard to reinforce the roofing assembly
- SBS modified bitumen base membrane (Polyglass)
- Self-adhered granulated SBS modified bitumen cap membrane (Polyglass)
- New ballasted rooftop guardrail system around HVAC equipment
- Reinstalled hatch guard safety rail system
The new SBS modified bitumen system provides enhanced durability, improved drainage performance, and long-term waterproofing reliability compared to the original ballasted EPDM assembly.
Project Challenges & Solutions
- Ballasted Roof Removal: The existing river rock ballast had to be carefully removed and cleared from the roof before demolition could begin.
- Active Commercial Site: Work was completed while the gas station and convenience store remained operational, requiring careful coordination and site safety management.
- Rooftop Equipment Protection: HVAC equipment and rooftop mechanical systems required protection and coordination during installation of the new roofing system.
- Rooftop Safety Improvements: A new ballasted guardrail system was installed around the HVAC unit to improve safe access for future maintenance.
PROJECT OUTCOME
The completed roof replacement resolved the ongoing leak issues and provided the building with a durable, modern roofing system. The new tapered insulation improves drainage, while the SBS modified bitumen membrane provides reliable long-term waterproofing.
With upgraded materials, improved roof safety systems, and a properly sloped insulation system, the Shell C-Station now benefits from a high-performance roof designed to withstand years of weather exposure and daily commercial use.
