basement cracks

January 18, 2008 1:29 PM

anyone have experience dealing with basement cracks?

I have some cracks on the wall of my basement, just on one side. The wall has been painted over with sealer many times over the years. It is a block wall. The one main crack was there when i bought the place, the inspector said it was ok, and that as long as the wall didn't bow out over an inch or so, i'd be OK. I think it bows maybe 1/4-1/2" now at the worst, where the big crack is. that crack is maybe 5 mm wide. I get no water in my basement, except a bit coming up from the floor when it rains for like a month straight.

Anyway, there are some other hairline cracks, which really seem to be cracks in the thick layer of sealer. I can't tell if they're new or not, but i think they are. I was just wondering how concerned i might be about the cracking down there...There are hairline stair steps, and horizontal, then of course the big one. I suppose the big issue is whether the wall is moving right (or how much it is moving)? If it is stable then I don't want to screw with it. I only paid $50k for the house, and it has been great so far, had it 14 mos. No problems. So, i don't want to put much money into serious and expensive foundation repairs! Planning on selling the place in a few years or renting it out. Anyway, what should i look for? Are these cracks a big problem? I put some sealer in the cracks, or over them, and that should help me see if they're opening up more over time....

Pics here, here here here here here

posted by Salvatorparadise to home & garden (8 comments total)

None of those look bad at all to me. Lots of older buildings have worse. Something like this is what you want. More than a simple "provide insulation" foam filler, less than full-blown foundation repair.
posted by TeatimeGrommit at 1:33 PM on January 18

They don't look that bad to me either, BUT, if you have seepage around the cracks it may be worse than it looks. If you see water anywhere near the cracks, get help. There is a saving grace even if there is water and that is that the cracks seem pretty high up, almost at ground level, which means the job of channeling water away on the outside will be easier.
posted by Pollomacho at 1:42 PM on January 18

my gutters are all rockin, and the grading away from the house is good...so that will help, and I plan to keep that stuff in top form
posted by Salvatorparadise at 1:48 PM on January 18

also, pollo, the crack is actually at ground level, or there abouts...my house is built up a few feet off the ground, so that crack is about where ground level is...
posted by Salvatorparadise at 1:54 PM on January 18

That's what it looked like. No water, no worries. Keep an eye on them during a downpour.

Just a thought, you could drill throught the crack and into the cavity in the cinderblock and fill that with spray-in expansion foam if you want a quick-fix type seal.
posted by Pollomacho at 2:17 PM on January 18

Get some crack monitors (or make your own) from a civil engineer and monitor the cracks monthly. If you see substantial and/or rapid movement, act.

"Act" means hire a civil engineer to look at the structure and evaluate it. For $300-500, you can get a quick analysis to see if you need to do something and what.

Usual culprit is drainage or water leaking. Site-specific factors must be considered, as a crack, in an of itself is evidence of adjustment, not necessarily imminent failure.

Homemade crack monitor is a piece of tape on each side of the crack, with a line drawn across both with a ruler. Only measures one axis of movement, though. A real one is a plastic thingie that indicates movement with calibrated displacements in multiple axes.
posted by FauxScot at 2:21 PM on January 18

Sealing the cracks with something waterproof should help limit further damage, but it's best to seal from the *outside* when possible. I mention this since you've said that the cracks are about ground level so you should be able to access from the outside.
posted by TeatimeGrommit at 3:16 PM on January 18

Don't laugh- when I was a kid, we had a pretty heinous crack+leak. Dad tried everything, including digging out around the area outside and sealing it that way. Nothing worked. He then mixed up some Bondo car dent repairer stuff, and it never leaked or cracked again.
posted by gjc at 8:22 PM on January 18