That tip about wetting the subgrade before pouring saved my hide today

Old timer named Jerry told me last month to always dampen the subgrade if it's hot out, and I thought he was just being fussy. Hit a 90 degree day on a driveway in Phoenix and the concrete set up in like 20 minutes before I could get a good finish on it. Anyone else run into this kind of heat-related panic?

2 comments

2 Comments

alicecooper3d ago

Well now, I've got to respectfully disagree with that tip. Wetting the subgrade in Phoenix heat is asking for trouble if you ask me. I poured a patio in Mesa last July and made that exact mistake, ended up with a muddy mess that took forever to get the moisture out of the mix once it hit the ground. The water just sits there and creates a weak bond at the bottom, especially if you've got any clay in the soil like we do out here. I've had better luck just working faster with a retarder added to the truck and keeping a mist on the surface while finishing. Jerry means well, but that trick doesn't play the same way in the desert.

amymason2d ago

That's exactly what I found too. I started using a retarder and just misting the surface after a bad experience with a muddy base that caused the whole slab to dust up on me.