When you live in places like New York or one of the New England states, you’re almost certain to have a basement. For many people, it can be a great living space, but living in a place with cold weather does present some unique issues for making a finished basement.
Depending on where you live, you may have a high water table. Where this becomes an issue is in winter, when you can get what is known as freeze/thaw damage. Water is a rather unique molecule; as it freezes, it expands – unlike most other liquids. So, if you have a high water table, and a finished basement, any water under the floor or next to the walls can freeze, expand, and rupture your lovely flooring and walls!
This is not something you want to find out about after putting down beautiful hardwood floors. So, before starting a renovation project in your basement, find out where your water table is. You can do this a number of ways. The first is to check with your local government, sometimes they’ll have an engineering department – or even the water department – that will know about the water table.
Other sources of information are the USGS (United States Geological Survey), and the US Department of Agriculture; both have soil maps and charts. Very often these will indicate how the water table in a community varies over time. Typically, every area has a dry season and a wet season, and you need to look at the worst-case scenario – the highest level.
Once you have that information, find out the finished floor elevation of your home. Again, this is something you can easily find from the floor plans or the building department of your community. If you have a survey of the home, often times its elevation will be noted.
Sometimes it has the abbreviation: FFE, for Finished Floor Elevation. If you take that number and subtract about ten or twelve feet, you can determine where your basement is located. After that, it’s a simple matter to compare the water table elevation to your basement elevation, and then you’ll know if there’s a potential problem.
If in fact you have a problem, a simple means of solving it is the installation of a sump pump. Typically, you dig a low area in one corner of the basement, whichever is the lowest point of your home, and install a small electric pump. The pump’s outfall pipe should run to outside of your house, or into a nearby drain. This will effectively draw down the water table and prevent any freeze/thaw damage to your basement.