Old foreman told me to wet the ground before pouring. I thought he was crazy.

My first year on a crew in Phoenix, this guy named Rico kept yelling at me to wet the dirt before we poured a slab. I figured it was just extra work and skipped it a few times. Then we had a 100 degree day and the concrete set up so fast the finish looked like a desert floor. Cracked in a week. Now I always spray it down first. Anyone else had a boss give you advice that seemed dumb but saved you?

3 comments

3 Comments

wright.leo19d ago

There's this old timers' saying I heard once, "dry dirt is concrete's enemy." Actually read it in some concrete handbook my dad had from the 80s. The science makes sense though. When you pour on dry ground it sucks the moisture right out of the bottom of the slab before it even has a chance to cure properly. That's why your finish went to crap. You need that water in the dirt so the concrete stays wet long enough to set hard all the way through. I swear half the stuff those guys know sounds like witchcraft until you see it work.

wren_mitchell19d ago

@wright.leo you ever seen what happens when someone tries to cheat by wetting the dirt right before the pour? Is that just as bad or does it actually help...

hannah_wells18d ago

Wait, did your slab really crack that fast? Man, that sucks. I feel for you. I had a similar thing happen with a retaining wall early on. My boss kept telling me to mist the forms before pouring and I thought he was just being extra. Ended up with a wall that looked like a sponge because the wood sucked all the moisture out. It's wild how those little tricks can make or break a job. I bet you never skip wetting the ground again after that nightmare.