Prevent Basement Flooding with Good Drainage
LESLIE: Mike in Maryland’s dealing with moisture in the basement. What’s going on?
MIKE: Well actually I’m having a problem with water coming in and I don’t know if it’s – we have Bilco doors in the back and whenever it rains we have a sump pump which pumps the water out but it seems like we’re getting a lot more water than – and it’s an unfinished basement. About a third of it’s unfinished and that’s where it seems to be coming in. And I’m at my wit’s end because I was told to put some kind of a sealer on the floor and on the walls and I did that but it doesn’t seem to be working.
TOM: Mike, I hate to tell you but no matter how much of that sealer you put on your basement, your house is not going to float.
MIKE: (chuckling) Darn, well …
TOM: So what you need to do here …
MIKE: … I guess we’re stuck in the neighborhood we’re in then.
TOM: Your problem – yeah, you’re not going to sail down to a new lot. Your problem is gravity, alright? So let’s deal with that.
First of all, the fact that you’re getting water in your basement after a rainfall is actually very good news because that means that the source of this is not a rising water table; hence, you really don’t need that sump pump if we can get this drainage problem fixed.
TOM: And drainage is the problem. So I’m going to tell you how to do your own wet basement inspection here from the 20 years I spent doing these sorts of things as a home inspector. I want you to go outside first and I want you to look at the ground right around the foundation perimeter. In a perfect situation you’re going to want to see soil that’s sloping away from the wall. I’d love to see it drop about six inches over four feet. I’d also like to make sure that there’s no top soil; no mulch; no stone; no river rock, you know, trapped by a brick edging; or anything like that that’s going to impede water flow away from the foundation walls.
LESLIE: From getting away.
MIKE: Oh, OK.
TOM: The second thing – and this is even more important than the grading. This is like 75 percent in terms of the importance scale – is your gutter system. You have to have a gutter system. The gutters have to be clean. The downspouts have to extend water not right to that corner of the foundation but out four, five, six feet away.
TOM: If you’ve got a wet basement the water has to get pushed out well away from the first few feet of the foundation. The reason …
LESLIE: And you have to make sure you have sufficient downspouts; enough of them.
TOM: That’s right. You need one downspout for every 600 to 800 square feet of roof surface.
MIKE: Now, I know in the front of the house where it’s finished they had – because the house is over 25 years old. They had the tubing that goes out of the front spouts through the front of our yard that they dug a trench and it goes into the gutter or the (INAUDIBLE) trench in the front but in the back that’s not the case.
TOM: Well, is the water coming in the back or the front?
MIKE: In the back.
TOM: Alright. OK.
MIKE: So it’s in the unfinished part of the back of the house.
TOM: Well, where do the downspouts discharge for that area?
MIKE: Just up – almost up against the house. I think (INAUDIBLE) …
LESLIE: (overlapping voices) That’s the problem.
TOM: (overlapping voices) Well, there you go. Well, there you go. See? We solved it. You’re going to go – listen …
LESLIE: You have no idea how much of a difference this is going to make.
TOM: Mike, this is going to be huge.
Here’s what I want you to do just – you’re going to – just to entertain us. I want you to go out to the home center and pick up a couple of links of downspout and hook it up to the end of that discharge. I don’t care if it’s eight or ten feet out. Just drop it out there so all the water now runs away from the foundation …
TOM: … and then watch what happens.
LESLIE: And pray for rain.
TOM: Pray for rain. (Leslie chuckles) You’re going to eliminate this problem. This is so obvious and so easy to fix you’re going to kick yourself when you see how quickly it remedies itself.
MIKE: Well, what I’m kicking myself now, after speaking to you guys, is the two plumbers that I’ve had out here, they have talked to me about raising the level of the sump pump surround and …
TOM: If you call a plumber you’re going to get a plumbing solution.
MIKE: Response, right.
TOM: You understand what I mean? This is what these guys work with all the time so they’re going to give you something – it’s not that they’re being dishonest with you. [It’s just that] (ph) their area of comfort is how to maybe improve the work of the sump pump. You know, my area here is trying to keep that water out to begin with …
TOM: … and when a house floods because of a rainfall it’s always drainage. You should be looking up not down.
MIKE: Well, thank you very much.
TOM: You’re welcome, Mike. Thanks so much for calling us at 888-MONEY-PIT.