Inman

Keeping water out of the basement

Q: When it rains, I have a problem in my basement. After the earth is saturated, water enters through the foundation. I have an attached house and live on a hill. We have two bedrooms and a bath in the basement. The water flows under the floor, which is elevated about 4 inches. I haven’t had any mold problems because I put towels against the foundation wall to soak up the water. But sometimes I don’t get it all and it travels down the sloping floor to the drain in the middle of the garage. It looks as if the previous owners have tried a patch or two with little success. Any ideas?

A: There are a couple of ways to stem the floodwaters, but there is no easy fix. Both solutions require a significant investment of time and money.

We believe that installation of a French drain around the outside of the foundation is the best choice. If done properly it will direct groundwater outside of the house where it belongs.

Another, less desirable solution is to install a sump pump inside the basement to direct water to the outside.

We surmise by the description of your house that it is built into the side of the hill. That means that in order to install a French drain, you must excavate a trench directing the water to the street. The trench should be at least as deep as the bottom of the foundation.

Install drain tiles in the bottom of the trench and backfill the trench with gravel. This will allow water from the saturated earth to percolate through the gravel into the drain tile and empty into a catch basin or the street.

You’ll probably have to excavate a trench at least 10 feet deep at the deepest point. That is a lot of dirt to move and involves more work and expense than you might want to undertake.

If you do decide to go this route, we recommend that you undertake the project during the summer.

When the foundation and basement walls are exposed, apply a good moisture barrier on the concrete walls.

If you install a sump pump inside the basement, you would need to dig a trench around the interior perimeter of the basement, install drain tile on the bottom, backfill with gravel and discharge the pipe into a sump. A sump is merely a hole in the ground that acts as a catch basin for the water.

Place a sump pump in the catch basin and run a discharge line from the sump pump outside. Make sure the water discharges away from the house’s foundation.

Water will still seep through the basement walls, but if you opt for this choice it will be directed out of the house as quickly as possible.

You might be tempted to forgo the sump pump and discharge an interior drainage system into the garage drain. We do not recommend this.

The condition of the old garage drain is unknown, and it is always best to direct water away from the house.

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