Lumber prices are climbing while single-family starts fall for a third straight month. When price and demand move in opposite directions, the answer is on the supply side.
What moved
Southern Pine 2×12 rose 10.7% month over month. Southern Pine 2×6 was up 7.5%, standard SYP framing lumber more than 5%, and spruce studs nearly 6%. Truss pricing, which lags dimensional lumber, rose 8.8%. RoMac Building Supply’s Whole House Commodity Index, which prices the materials package for a 2,200-square-foot wood-frame home, rose 1.8% in July to $55,287 and is up 7.2% year over year.
That index is a Central Florida wholesale measure, not a national one, so the absolute number travels poorly. The directional signal on species-level pricing does not.
Three supply constraints stacking up
RoMac president Jake Trapp attributes the gains to supply rather than demand, and there are three distinct pressures behind that.
First, Canadian softwood now carries a combined 35.9% duty burden, which effectively prices a meaningful share of historical U.S. supply out of the market. Second, domestic sawmill capacity is down 6% year over year, a second consecutive quarterly decline. Mills that closed during the 2023 and 2024 demand slump have not reopened, and restarting a shuttered mill is a twelve-to-eighteen month decision that nobody makes on a soft starts number. Third, American logs are moving to China after it lifted a pest-control import ban, pulling raw fiber out of the domestic chain before it reaches a U.S. mill.
Any one of those is absorbable. All three at once, against reduced milling capacity, is how you get double-digit monthly moves on a single dimension.
It isn’t only lumber
Wire mesh posted the single largest increase in the index at 12.0%. Hot-rolled coil averaged about $1,109 per ton in June, and Nucor’s consumer spot price reached $1,130 per ton as of July 1. Architectural shingles rose 4.1% at wholesale, though the manufacturer picture is worse: Owens Corning, CertainTeed and Atlas each implemented 5 to 10% increases effective June 1 and a second round on July 1. Architectural metal roofing is up more than 25% since January, driven by 50% Section 232 tariffs on steel and aluminum.
For builders, the practical consequence is that escalation clauses written against a demand forecast are mispriced. Supply-side inflation doesn’t ease when your backlog softens. It eases when mills reopen or duties come down, and neither is on a schedule anyone can build into a GMP. Source: RoMac Building Supply.