The roof substrate — also known as the roof decking or sheathing — is the base layer that supports your shingles, membranes, or flat roofing material. If the substrate is rotten, warped, or weakened by leaks, no surface repair will last long. That’s where we come in.
We inspect and replace damaged roof substrates using high-quality plywood or OSB, ensuring the structure below your roof covering is strong, level, and ready to perform. Our team looks for signs of water damage, soft spots, mold, or sagging — and we fix it right, not fast.
Whether you’re upgrading an old roof, recovering storm damage, or dealing with years of wear and tear, we’ll rebuild the foundation properly before installing the new system. No shortcuts. No patch jobs. Just durable repairs you can rely on for decades.
When it comes to roofing, surface-level fixes won’t last if the base layer is compromised. At Evian Roofing & Masonry, we do the job right from the ground up — removing damaged decking, reinforcing framing if needed, and installing clean, solid substrate to meet Ontario Building Code.
Our crew handles residential and commercial projects, working on everything from pitched asphalt shingle roofs to low-slope and flat membrane systems. We ensure every new roof we build has the structural integrity it needs to protect your home or business for years to come.
If your roof is sagging, leaking, or has a history of patch jobs, you likely need substrate repairs. We’ll inspect it, give you a clear breakdown, and get to work — with no delays or surprises.
Built From the Ground Up
We repair roofs properly — starting with the structural layers. No shortcuts. Just work that lasts.
Experienced Tradesmen
Our crew has over a decade of roofing and carpentry experience — we know what to look for and how to fix it.
Straight Talk & Fair Pricing
We give clear explanations and detailed quotes, so you know exactly what’s being done and why.
Trusted Locals
Toronto-based, fully insured, and proud to serve our neighbours across the GTA with integrity and care.





