How to Repair Sinkholes
LESLIE: Now we’ve got Bill in Tennessee on the line who needs help with some sinkholes. Bill, tell us what’s going on.
BILL: I’ve got a patio in the backyard and at the end of my patio, I’ve got two huge sinkholes and then another sinkhole at the corner of my house. And this has been going on for about a year, year-and-a-half. They’re about 5 feet deep and, I don’t know, the circumference of about a manhole cover.
And just wanted to know what’s the cheapest and best way to take care of it where it doesn’t keep on happening. My patio is actually cracking where it’s sinking down a little bit.
TOM: So over the course of a year, these holes have revealed themselves?
BILL: For about the last year-and-a-half is when they started happening.
TOM: So very slowly but surely. And how old is this house?
BILL: About 15 years old.
TOM: Well, I mean it could be the result of loose fill that was put in these areas around the house when the home was finished – created, when it was done.
TOM: It could be the result of that. It could also be the result of some decaying material, like old trees or things like that that are in there.
Do you have any concern about it continuing to happen or do you think it’s pretty much done?
BILL: It’s pretty much done, it looks like, and …
TOM: So what I would do is I would fill those areas with clean fill dirt and that’s the most inexpensive dirt that you can buy. And then you want to tamp it down really well. So you put a little bit in, you tamp it, you put some more in, you tamp it. And then you finish it off with topsoil. And because it’s a sunken area, I would almost overfill it a little bit, because it’s going to settle down flat.
BILL: And what if it – like a year from now, it starts happening again?
TOM: Yeah, well, if that’s the case and it starts happening again, then at that point I would have to recommend that you got an engineer in to take a look at it, to see if we could figure out what was going on with the soils. You may need to do some borings around there to try to determine what’s in the ground and why it’s sinking.
BILL: OK. Well, that sounds great.
TOM: Alright. Well, good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.