I'll bite, why would the tariff help the Canadians?
What this has really done is make Canadian producers far more cost-efficient in markets where the U.S. tariff doesn't apply -- which means everywhere else in the world outside the U.S. With production costs that are 30% lower in Canada, U.S. mills can't even compete with Canadian producers in the global market.
So the end result of the tariff is that you've got lumber mills shut down all over Oregon and Washington, and U.S. consumers paying prices for lumber that are 30% higher than they should be.
This is why import tariffs are almost always utterly senseless.