Wood panel makers are shutting down mills as homebuilding slows, which could push building material prices up even in a weak market — bad news for builders and anyone planning a construction project.

• Louisiana-Pacific is idling its big OSB mill in Jasper, Texas, blaming weak demand.
• It is the third major block of North American OSB capacity pulled offline, after West Fraser shut mills in Alberta and Georgia.
• Housing starts are expected to fall to around 910,000 this year, with tariffs and a sharp drop in immigration cutting demand.
• Cutting supply faster than demand falls can create a bottleneck, and buyers who rush to stock up make the squeeze worse.
• Home prices are already down more than 8% nationally, close to the drop seen in the last housing crash.

Outlook: Expect OSB prices at building supply stores to rise over the next six months even as the housing market keeps cooling.