My basement floor patch keeps cracking after a few months

I used a concrete patch mix from the hardware store on a 2-foot wide hole in my basement floor about 4 months ago, and now there's a hairline crack running down the middle again. My neighbor said I probably didn't wet the edges enough before pouring it in. Anyone have a trick for making patches actually stay put in a damp basement?

2 comments

2 Comments

sam_thomas2d ago

Oh man, I hear you on that. I've patched basement floors more times than I care to count. Sounds like your neighbor was probably right about the edges not being wet enough, but the bigger issue might be the concrete mix itself. Standard bagged patch has too much sand and not enough binder for a damp basement floor. Try grabbing a bag of hydraulic cement instead, it actually expands a little as it sets and holds tight in wet spots. Scuff up the edges of your hole with a wire brush real good, soak the whole area with water until it stops soaking in, then mix your hydraulic cement pretty stiff. Tamp it down hard with a scrap of 2x4 to get rid of any air pockets. That stuff cures in like 10 minutes so work fast. The other thing nobody talks about is expansion joints. If that patch is close to the wall you might need a little gap there to let it move without cracking.

oscar7432d ago

Heard a contractor on a podcast saying the same thing about hydraulic cement and expansion gaps, that's probably your best bet. Sounds like @sam_thomas nailed it with the preparation steps too, so maybe try his method but leave a small gap near the wall next time.