Water Coming Up Through Basement Floor
LESLIE: Jim in Pennsylvania is on the line with moisture. What’s going on over at your money pit?
JIM: OK. I live in an old home that has a wrap-around porch. The only wall that’s exposed is – that goes out to the end of the porch is our backyard. My backyard slopes very gently downhill. It’s been landscaped with several swales and I never have standing water in my yard. I have no drainage that goes out the back or anything.
As a matter of fact, I’ve lived here for 30, 40 years and I’ve never had water in my basement until 5 years ago when we had a tropical storm come up the coast, come inland and dump almost 20 inches of rain right on us. But two years ago, I had the same thing happen. This one dumped about 10 inches of rain.
OK. Water both times that I had to get out of there – out of my basement, which is finished. But anyhow, my walls – even during those storms, my exposed walls and other walls are completely dry and the water is coming up through, it looks like, the back side starting towards the middle of the back wall, through the floor. It must – I’m thinking it’s groundwater.
TOM: It’s not. It’s clearly not. And I know that with absolute certainty because it’s tied in with the precipitation. Whenever you have heavy rain and you get any type of leakage, it’s always drainage. It starts from the top, works its way down. It just happens to be showing up under the floor.
That can very easily happen because water can accumulate outside the foundation wall. Sometimes it goes into the walls and leaks through the walls. Sometimes it goes around the walls and pushes up through the floor. I’ve seen geysers show up in the middle of basement floors because somebody had a blocked gutter on the other side of the house. Water does strange things. But this is a drainage problem; that’s all it is. So you need to look at your drainage very, very carefully.
Now, you mentioned that you had a swale and I hope that swale is still working for you. If that swale is not working just by the swale itself, you may have to install a curtain drain at the bottom of that swale, to collect the excess water and run it around your house and then dump it out to a place that’s lower on the lot.
The other basic things that you could look at – and the very easiest thing is to look at – is your gutters. You need to have at least 1 downspout for every 400 to 600 square feet of roof surface. And those downspouts need to be extended 4 to 6 feet from the house, minimum. Minimum. Not just out a foot into a splash block but 4 to 6 feet away. I say that because whenever you have a water problem, we’ve got to move that water away from that first 4 foot or so of soil that’s around the foundation perimeter.
So, clean gutters are really important, downspout discharge is really important and then, finally, the slope of the soil at the foundation perimeter is important. But if you manage and maintain and improve the drainage conditions around the foundation perimeter, you won’t have enough water to push up around those walls and into the floor.
JIM: OK, OK. So a sump pump wouldn’t work.
TOM: No. I mean a sump pump will take the water out once it gets there but it doesn’t deal with stopping it from getting there in the first place.
JIM: The initial problem.
TOM: Right. And by the way, putting a sump pump in doesn’t do anything to improve the structural integrity of the foundation because, again, that water has to go around that foundation to get to where the pump is.
So, deal with the drainage, keep that soil as dry as possible and you’ll make the whole thing go away.
JIM: OK. Thank you.