beth_hunt•16d agoProlific Poster

Saw a house foundation in Phoenix that had me scratching my head

I was down in Phoenix last week checking out a buddy's job site, and I noticed this new build foundation that had these huge control joints cut way too far apart, like 20 feet. The finisher told me it's fine because the rebar is heavy, but I always thought you gotta keep them closer to avoid random cracking. Is it better to trust the rebar or rely on proper joint spacing in hot climates? Has anyone else seen this debate play out on a pour?

2 comments

2 Comments

stella_lee16d ago

Gotta disagree with that finisher. I've seen plenty of Arizona pours where the sun just bakes the moisture right out. Heavy rebar helps with structural loads but doesn't stop shrinkage cracks from forming. 20 foot spacing is asking for a spiderweb look down the line. I'd cut them at 10 to 12 feet max in that heat. The rebar holds it together, sure, but the joints guide where it cracks.

seanperry16d ago

Stella's got the right read on this. The way I've seen it work in the desert is the rebar keeps the slab from falling apart, but those wide joints just let the cracks wander wherever they want. Stick with the 10 to 12 foot spacing and you'll have a way better looking floor five years from now.