Hot take: I was wrong about using a 3/8 inch joint for everything

For the longest time I thought a thicker joint was just stronger, period. Then I saw a whole wall on a job in Tacoma start to crack along the mortar lines after a single winter. The foreman, this old timer named Ray, pointed out that the thicker mortar didn't let the brick expand and contract right. Now I stick to 3/8 for most stuff but go down to a 1/4 inch joint for softer brick in wet climates. Anyone else adjust their joint size based on the brick type and location?

3 comments

3 Comments

the_angela1mo ago

Wait, so how do you figure out which brick counts as "soft" enough to need the smaller joint? Is it just by feel, or is there an actual test you do before you start laying?

ellis.nina1mo ago

My buddy learned the hard way on a job with reclaimed bricks. He thought they felt solid, but his first mortar line just sucked all the moisture out and set in about ninety seconds. The whole batch went off like concrete. After that, he started doing a quick water test - if a brick drinks a sprinkle on its face almost instantly, it gets the fat mix.

elliotw3715d ago

Oh man, the water test is everything. You just flick a few drops on the brick face. If it vanishes in a couple seconds, that thing is thirsty and you need the wetter mix. If it just sits there beading up, you're good with a standard joint. It's way more reliable than just poking it.