My boss in Phoenix swore by a 3/8 inch joint for cinder block, but I had to learn the hard way.

He was a great guy, taught me a lot, but he was stuck on that 3/8 inch joint for everything. We were doing a big garden wall last fall, and he was out sick for a week. The specs for the job clearly called for a 1/2 inch mortar joint. I figured, what's an eighth of an inch, right? I did it his way to keep things moving. When the inspector came, he failed the whole first course because the joint was too thin. I had to tear out and re-lay about 40 blocks by myself. It was a long, quiet day. Now I always check the plans twice, no matter what anyone says. Has anyone else had a plan detail bite them because you went with 'the way we always do it'?

2 comments

2 Comments

the_patricia10d ago

You ever get a copy of the specs and physically highlight the joint size on your set? I started doing that after a similar mess, just a big yellow mark right on the page so my brain can't ignore it.

emeryking10d ago

That eighth of an inch really does matter for structural reasons. Mortar joints are sized in the plans for a specific load and bond. It's a tough lesson but checking the specs always pays off.