How to Fix a Basement Crack
LESLIE: Next up, we have a call from Kelly in Wisconsin who has a basement issue. That sounds interesting.
What’s going on?
KELLY: Well I got a block basement and I know I’m not in the proper soil condition for that but that’s how the house came. Halfway up from the basement to the ceiling of the basement, I’ve got a crack in it.
LESLIE: So is it concrete block from floor to ceiling?
KELLY: Yes it is.
TOM: And is the crack horizontal?
KELLY: You mean cross-ways? Yes.
TOM: Cross-ways, yes; horizontal, not up and down. OK. And how big is the crack? Does it go end to end? Is it only in the middle of the wall? Is it more open in the center of the basement than towards the ends?
KELLY: It’s more open in the center than on the corners there.
TOM: OK, Kelly. I know exactly what’s causing this problem. It’s frost heave. What you’re experiencing is the soil outside of that basement wall is getting too wet. And as it gets wet and it freezes, it expands and puts horizontal pressure on that block wall. And that’s why you see the crack. It’s probably, in most cases, a couple of blocks below the soil line and it’s going to get worse over the seasons. It happens very slowly; kind of a ratcheting effect. Every winter it gets a little worse and a little worse and a little worse.
I want you to improve the drainage conditions outside your house. So I want you to add some dirt around the foundation perimeter so that the soil slopes away from the wall. I want you to make sure that that drops about six inches over four feet, so you have a nice slope, and add some mulch or some grass seed on top of that.
LESLIE: Also make sure that your downspouts are depositing the water at least three to six feet away from the foundation. You don’t want it going right back into the dirt right in your foundation.
TOM: I think you’ve caught this early enough where if you get the drainage conditions repaired, you’ll take the pressure off that wall and it won’t get any worse.
KELLY: OK, thank you.
TOM: You’re very welcome.
This is The Money Pit Home Improvement Radio Show. The number is 1-888-MONEY-PIT.