Tried wetting my forms the night before a big pour and it actually helped

Had a 20 yard driveway pour last month here in Phoenix where the sun was beating down and I kept getting edges drying out way too fast on me. An old finisher I know told me to hit the forms with a garden hose the night before so the wood would soak up moisture and not pull water out of the concrete. I was skeptical but figured what the heck and tried it on half the forms as a test. The wetted side stayed workable way longer during finishing while the dry side was already crusting up around the edges. Did any of you guys grow up learning this trick or did I just miss out on some basic knowledge?

2 comments

2 Comments

ellis.mia6d ago

That old finisher knew what he was talking about. Phoenix heat is no joke, I've seen edges set up like concrete cookies in ten minutes flat out there. Did you notice any difference in how the concrete stuck to the wetted forms versus the dry ones when you stripped them? I've always wondered if that extra moisture messes with the release or makes it stick more.

ray_hernandez6d ago

Think you're close but I gotta push back a little on that @ellis.mia. Wetted forms actually help in my experience, the water creates a thin barrier that stops the concrete from grabbing too hard. Dry forms suck up moisture from the mix itself and that's where you get sticking problems. I've stripped plenty of forms in Arizona summer where the release agent just cooked off before the pour even started. Ever tried using a fogger to keep the forms damp instead of just spraying them down?