How Escalating Tariffs and Canadian Mill Closures Are Reshaping U.S. Lumber Supply
The U.S. homebuilding industry is facing a lumber supply disruption that has been building quietly for years — and is now arriving all at once. Canadian softwood lumber, which has historically supplied roughly 25–30% of U.S. demand, is being squeezed out of the market by a combination of sharply escalating tariff rates, weakening mill economics north of the border, and a structural inelasticity in the lumber supply chain that makes rapid recovery nearly impossible.
This is not a temporary fluctuation. What is unfolding in 2025 represents a structural shift in where American builders will source framing lumber — and at what price — for years to come.
The Tariff Escalation: A Timeline
Canadian SPF (spruce-pine-fir) lumber has been subject to U.S. countervailing and anti-dumping duties under the Softwood Lumber Agreement framework for decades. But the rate increases seen in 2025 are unprecedented in their pace and scale:
| 2025 | |
|---|---|
| Jan - July duty rate | 14% |
| Aug - Sept duty rate | 35% |
| Oct. - going forward | 45% |
The cost comparison below shows exactly how the math breaks down by company-specific duty rate. As the numbers make clear, the economics of sourcing Canadian SPF have fundamentally changed:
| USA Cost | RL Print (FOB mill) | |
|---|---|---|
| 0% Duty | $425 | $425 |
| 36.5% (WFG) | $425 | $580 |
| 44.5% (IFP & All Others) | $425 | $614 |
| 57.6% (CFP) | $425 | $670 |
The cost math is stark. A Canadian mill selling lumber at $425/MBF FOB faces a U.S. landed cost of $580–$670 depending on duty rate — a 36–57% premium before transportation or dealer margin. At those levels, Canadian SPF economics simply do not work, and mills are responding by idling or closing entirely.
The broader consequence is a lumber supply that is becoming structurally smaller — and far less able to respond when U.S. housing demand eventually rebounds. The lumber industry is notoriously inelastic: building a new sawmill takes years and hundreds of millions of dollars. Only two companies worldwide (Bid and SLR) supply the essential equipment. And lumber represents just 50% of a log’s value — the other half (chips, sawdust, hog fuel) requires separate offtake agreements with pulp mills and paper mills that must also be in place before a new sawmill can be viable.
The Outlook: Covid-Era Pricing Is Coming
The projected trajectory of Canadian lumber shipments to the U.S. tells the story clearly:
| Year | CDN Shipments to U.S. | Notes |
|---|---|---|
| 2024 | 11.8 billion fbm | Baseline year |
| 2025 | 10.1 billion fbm | Assuming balance of year at Aug–Sept avg. |
| 2026 | 8.6 billion fbm | Assuming continuation at current pace |
Even in a flat demand environment, a supply reduction of this magnitude will create significant pricing pressure. Any increase in U.S. housing starts will amplify shortages dramatically. As Kip Fotheringham notes: with a flat demand market in 2026 or any increase in demand, Covid-type pricing is inevitable.
What This Means for Builders
For homebuilders and their procurement teams, this is a present-tense supply chain risk that requires active management now:
- Diversify your lumber sourcing. U.S. domestic mills (Southeast, Pacific Northwest, South) are the most logical alternative, though capacity is constrained and pricing has already moved.
- Lock in pricing where possible. Forward contracts and longer-term supply agreements with distributors provide cost predictability. The window to lock favorable pricing before a demand rebound may be short.
- Re-examine your framing specifications. Engineered lumber products — LVL, I-joists, LSL — offer substitution flexibility and may provide more supply stability than commodity SPF.
- Build tariff escalation clauses into contracts. Any construction contract without explicit materials escalation language leaves significant risk on the builder’s side. This is a lesson from 2020–2021 that should not have to be relearned.
- Communicate proactively with buyers. Buyers who understand market dynamics are better equipped to make decisions and less likely to walk when prices adjust.
The fate of Canadian lumber is largely decided by forces outside the industry’s control — trade policy, mill economics, and tariff structures that show no sign of easing. What remains within builders’ control is how quickly and decisively they adapt their sourcing, contracting, and pricing strategies.
References
- Fotheringham, K. (2025, October 30). The Fate of Canadian Lumber. So-lu-tions.com.
- U.S. Department of Commerce. Softwood Lumber from Canada: Countervailing Duty and Antidumping Duty Orders. Federal Register, 2025 updates.
- Random Lengths. (2025). Framing Lumber Market Report. randomlengths.com
- Forest Economic Advisors. (2025). North American Lumber Outlook. Mill capacity and shipment projections.
- National Association of Home Builders. (2025). Lumber and Panel Products Price Report. nahb.org
About the Author: Kip Fotheringham
Kip brings deep expertise in lumber supply chains, Canadian trade policy, and procurement strategy for U.S. homebuilders. Let’s have a conversation about proactive sourcing strategies that will protect your margins as the lumber market tightens.
