Builder buddies

My builder buddies dropped by the other day. They used to regularly drop in for blue eggs and, while here, comsume copious quantities of tea. I told them about the brick arches I wanted to build for my new secluded garden. I said that when I lay bricks I get cement all over the front of the bricks and spend hours sponging it off. Cut a long story short. They're coming round one evening next week to give me a crash course on brick-laying. Bless them. They said you supply the bricks and you supply the beer!!! We'll supply the expertise!!
Err? Yes? How good will that expertise be? If they're both pissed??