President Trump’s push for tariffs on Canada – and his subsequent delays and exemptions – are frustrating efforts to import lumber from the country and putting the building supply market on edge. The back-and-forth over whether tariffs will be imposed or not has businesses unable to trust price stability, and risks backing up the supply chain for US homebuilders. The reluctance to pay a tariff, which could be changed or cancelled any day, “freezes these markets up,” according to Don Magruder, who runs a building material company based in Florida. …Andy Rielly, president of Rielly Lumber in British Columbia, said he’s been in talks with long-term customers on how to divvy up the extra costs, but not everyone has been able to strike deals. …The US’s National Association of Home Builders chairman Buddy Hughes said tariffs risk worsening housing affordability. …The US Lumber Coalition said that lumber prices are only a fraction of homebuilding costs.