The U.S. Department of Commerce imposed tariffs of approximately 21 percent on imported softwood lumber from Canada in 2018, which is "remaking" the global supply chain for lumber. The NAHB tells MarketWatch that the tariffs are making it cheaper for American buyers to import lumber from overseas, rather than buying and shipping lumber from Canada. Canada's share of total softwood imports has fallen 8 percent from 2016 to 2018, while Norway's import share has grown from 0.00 percent in 2016 to 0.03 percent in 2018.
It’s not a literal wall, but actions taken by the Trump administration are blocking off the flow of imported lumber from Mexico to the U.S., raising prices for home builders and, some industry groups argue, holding back more robust activity in the housing market. (It’s also nudging up the share of consumption that goes to domestic producers, but not by much – from 67 percent in 2016 to 69 percent in 2018.)