U.S. lumber producers praise Commerce Dept. action but Canada blasts it and threatens litigation.

Executive order also seeks to promote "Hire American" policy, by tightening up on H-1B visa program for skilled workers.

Repairs to 17,000 lane-miles could start in 2018

Tall mass-timber frames are coming into favor not only because wood is a renewable structural material but also because timber structures are typically faster, safer and simpler to build, compared to steel and concrete construction.