Question on concrete

[Steven J Corpstein]

I poured a small wall, 12" high x 8' long x 4" thick, how long before I pull the forms off? I used bagged Ready Mix with the gravel and sand in it and the temp today here is 65*.

[Duan Packard]

Forms can come off in as little as 4hrs if no stress or traffic.
Best wait 24hrs

Duan

[Jim Benante]

The longer you leave them on the slower the concrete will cure and the slower concrete cures the stronger it is. I'd leave them on for a couple days, but you can take them off as soon as the concrete sets up.

[Ben Grunow]

Concrete reaches more than 80% of its design strength in 24 hours and 100% in 28 days, dont ask why but that is the truth.

24 hours is a safe bet. Wet the concrete if possible to prolong the cure and help avoid cracking over time. The water softens things a little and slow the cure to allow the concrete to shrink more evenly and crack less.

[Russ Filtz]

I would keep it wet/moist for at least a week. A wall may not be as critical as a slab though. The slower you cure concrete, the stronger it gets. If you don't keep it wet you can get fast drying at the surface which can promote surface cracks.

[Robert Mickley]

One of the tricks learned from jack of all trades brother.After it cures 4 or 5 hours, keep the exposed parts covered with wet straw. We kept his driveway wet for two or three weeks his drive way has been in 30+ years and it was poured out of hot concrete he brought home from work when he was driving a mixer. the only damage in it is right at the road. Of course years of backing loaded semis in on it did that. other than that its crack free

[Jim O'Dell]

Think of cuiring concrete just like drying fresh cut wood. There is moisture all the way through the concrete, it dries first from the outside, the as it cures the moiture in the middle dries. That's when the insignificant surface cracking apears. Concrete is actually porous, and the moisture dries out slowly. Keeping the surface wet for a while slows down the difference in surface to inside drying, so that the cracks are fewer. The surface cracks we are talking about here are different than the cracking that happens from the ground shifting. The former is no problem, the latter is bigger problem. Jim.