The Plywood Tariff Quietly Raising Deck-Repair Bills on Toronto Roof Jobs
When a roof comes off, the part nobody budgets for is what is underneath. Soft, rotted, or delaminated plywood decking has to be replaced before a single new shingle goes down, and in 2026 that replacement got more expensive for a reason most homeowners never see coming: lumber trade policy.
It is the classic hidden line item. The homeowner approved a number for “a new roof,” and then learns mid-job that the wood beneath the old shingles needs work, at a per-sheet rate that is higher than it would have been a couple of years ago.
The tariff hiding under the shingles
In October 2025, a 10% Section 232 tariff took effect on softwood timber and lumber, stacking on top of long-running antidumping and countervailing duties already weighing on the Canadian softwood trade.
Roof decking is plywood and oriented strand board, both made from exactly the softwood caught up in this dispute. When the lumber market gets squeezed and volatile, the sheet goods used to re-deck a roof get pricier and less predictable, and that flows straight into the per-sheet replacement rate on a roofing quote.
Why this shows up as a “surprise” charge
Most roofing quotes assume the existing deck is sound and price decking replacement as a conditional add-on, billed per sheet only if it turns out to be needed. The contractor cannot know how much is rotten until the old roof is off and the deck is exposed.
On older Toronto homes, it is frequently needed. Decades of small leaks around chimneys, valleys, and skylights soften the plywood in exactly the spots that matter, and the homeowner only learns the extent when the tear-off reveals it. With lumber costs elevated, that add-on is no longer trivial.
How to avoid being blindsided
Ask before the job, not during it. A good contractor will quote a clear per-sheet rate for decking replacement up front, and will inspect the deck, attic, flashing, and ventilation as part of the estimate, so the range of likely outcomes is on the table before you sign.
This is also a place where contractor honesty separates the field. A crew paid by the sheet to replace decking has an incentive to find more of it; a reputable firm documents what it replaces and shows you the damaged wood before it goes in the bin. Established firms protect their reputations more carefully than transient ones, which lowers the odds of an inflated decking bill.
The deck is the roof you never see
It is worth remembering why this matters beyond the invoice. The decking is the structural base the entire roof system fastens to. New shingles nailed over soft, delaminated plywood will not hold properly and will fail early, so skipping necessary decking work to save money is a false economy.
The decking is the part of a roof you never see and never think about, right up until it is the line item that moves your total, or the reason your new roof leaks in five years. Pricing it honestly before the work starts, and replacing what genuinely needs replacing, is the difference between a quote and a guess.
