Having trouble with water in and around your basement probably is not high on your list of concerns. Yet, depending on where you live – it can and should be. If you have an especially large basement, and your area has a high water table, you can have what’s known as hydrostatic pressure pushing in on your house from the basement floor and the outer walls.
Now, when your house is first built, the architect and/or engineer will take that pressure into account in the design of the walls. Yet, while the floor and walls are strong enough to stand up to the water, they may not be sealed to prevent water from seeping into your basement.
First off, concrete and cinder block walls are rather porous; so water can trickle through and collect in your basement. The same is true of the flooring; usually it’s nothing more than a six inch to twelve inch slab of concrete.
So, one way of dealing with this seepage is to seal the walls and floor. If you go to a hardware store, they’ll have waterproof sealant that you put on with a roller – just like paint. Now, these sealants have their limits; if the water table is especially high and/or you have a very large basement, the water pressure (the hydrostatic pressure) can get high enough to push the water through the sealant.
If that happens, you’ll need a pump system to collect the water. In the case of the walls, you’ll need pipes places around the outside perimeter of the house. Ideally, you’ll want to dig down to the footer of the walls and create a trench at least a foot wide. In the bottom, put some gravel and a perforated pipe, which will run around the entire perimeter of the house.
Depending on the way the ground slopes around your house, you may be able to just run a drain pipe off to one side, and then let gravity take the water away from the house. If the ground is high all the way around your house, then you’ll need a pump to bring the water up from bottom of the trench, and pump it away.
In terms of water under the floor, ideally you want a bed of gravel under it, and then a perforated collection pipe at the low end of the floor. Once again, a pump is needed to remove the water and send it off. If you’re trying to drain water from under an old floor that you can install gravel and pipes under, you can create a sump. This is a small square hole – a couple feet across – and you dig it at the lowest point of the floor. Then you set a pump in the hole and fill it with gravel.
By using these various methods, you can help to dry out your basement and make it a splendid living space.