Why do you think CLAC was formed?
Ask the people on the left coast that can still remember the leaky condo roof scandal.
They had protectionist measures in so only BC union members got the work,mostly 115a(operating engineers)because the work could only go union clac was formed and they undercut all the big unions jobs on the coast and did some major damage.
CLAC also put marine pipeline out of bussiness in Alberta undercutting the wages and because they were a union,they got the work.

So CLAC is a union that competes with other unions? Interesting. They usually back each other don't they?