Curtain Drain Solution for Flooded Basement
LESLIE: Lee in Arkansas is dealing with a basement situation. What’s going on?LEE: My question is I want a French drain around the house. How deep does a French drain need to be? Do I have to go down to below the level of the basement or can I just run an average trench which goes down about three feet?
TOM: So you have extended downspouts and you have grading and you’re still getting water?
LEE: Yes, sir. The property behind me is on a hill, so I’m getting the runoff from that hill which fills up the drainage – a small little ditch they have running off into the wet-weather creek.
TOM: (overlapping voices) OK. OK.
LEE: But, over time, it just – the whole ground, the water in my backyard, just gets saturated.
TOM: I see.
LEE: And it lasts that way for about a week after a heavy rain.
TOM: OK. So the solution here may not be a French drain right up against the foundation because I don’t think that’s the best place to collect the water. But what you might do is create what’s called a curtain drain between your house and this hill.
Now, a curtain drain is a trench that’s essentially about 12 to 18-inches wide and deep that is filled with stone and then you have a perforated, solid, PVC pipe embedded and encased in more stone all the way around it. And then, when you’re done, the last layer is filter cloth and then some soil and then grass. So when you’re done, you don’t see it; it’s completely underground. But what happens is as the water runs down the hill, it falls into this trench, comes up into the pipe and then you run the pipe out somewhere to daylight where you can drain the water. Typically, when you have a hill and you need to intercept water, that’s the way you do it.
If you let the water come against your house, yeah, you could intercept it there; but by the same token, you’re saturating the soil, which makes the house unstable. So I’d rather see you try to collect it farther away from the foundation for that reason. Does that make sense?
LEE: Absolutely and I was going to do that. I was also going to out six feet around my house, all the way around my house, and French drain it and have that going into the wet-weather creek as well.
TOM: Well, let’s do this one step at a time, Lee. Let’s not do everything at once.
TOM: I would put the curtain drain in first and try to collect that water coming off the neighbor’s property. And you know, measure it; see how it goes. Wait a year and then you can always put the next set of drains in after that. But big project, so …
LEE: (overlapping voices) OK. And I’m pretty handy. I think this is something I can do myself. I had a quote for over $10,000.
TOM: Yeah, it’s pretty simple. Just make sure that you get a ¼-inch-per-foot slope on the pipe so that the water will eventually run off and out.
LEE: OK, excellent advice as always. Thank you very much.
TOM: Alright, Lee. Good luck with that project. Thanks so much for calling us at 1-888-MONEY-PIT.