Causes of a WET Basement

Use and enjoyment of your basement space is threatened when it floods on a regular or semi-regular basis. For the unfortunate among us, more than one cause may be contributing to your own personal basement Nile. Here are places to check.

Believe it or not, this area of the house farthest away from the basement could be a cause of basement dampness or puddles. If there is a hole in an area of the shingles or at a connection to gutters, a chimney, or another plane of your roof, water can run under the support wood of the roof and find a wall to flow down. This roof leak flow may be visible inside or it may stay between the studs until it reaches your basement. Of course, your problem will be much bigger than just a basement flood, with possible mold inside walls and more. Let’s hope this is not a cause for you.

Good old gravity: water will respond to it and seek the lowest level. Therefore, if your bathtub, sink, dishwasher, upstairs laundry facilities, or garbage disposal is leaking, besides making a mess at the site of the problem, the water may travel along the pipes to find the basement. This is another yuck of a situation.

These are obvious suspects to check: the hot water heater, a clothes washer, a basement wet bar or refrigerator with icemaker. In the grand scheme of causes of basement wetness, these are the easier problems to address.

Other obvious sources for wetness in the basement are doors and windows. If you have what I call “Bilco doors,” a pair of wooden or metal doors which are at an angle to the house foundation and which cover a set of stairs going to a full-sized door directly into the basement, check these during rain to see if water is coming down the stairs. Also, check the seals around windows in the basement. These are another easier fix.

Now, you may need to go explore behind the walls if you have a finished basement. Pipes bring clean water into your home (whether well or public water is the source) and pipes take the dirty water out. Older homes can have iron or steel pipes with corrosion – even a pinpoint hole will cause a leak. Also, the fittings may be loose or leaky. Please do not assume that a sump pump is installed correctly. A few DIY creative homeowners have been known to create bizarre, incorrect sump pump configurations which do more harm than good. So, don’t unreservedly trust the prior owner who put in the pump.

The above causes involved water flow from one place or another. The next items on the list address groundwater. Most basements are not equipped to withstand sitting in permanent swamp conditions. As above, some causes are easier than others to correct.

Unfortunately, we're not done yet. There are more possible causes of basement wetness.

The fat pipe which takes your shower, toilet, sink, and washing machine water into the septic tank or sewer system can corrode, crack, or partially break. Sometimes this can result in water seeping into the ground before it reaches its destination. Eventually, the soil at the break becomes super-saturated. If this is close to your house foundation and basement, basement dampness can occur.

If any of your gutters have leaky holes or if they overflow and spill during a rainstorm or snow melt, that water soaks into the ground next to your basement. Also, if any of your downspouts leaks or just does not carry water far enough away from the house foundation, the water soaks into the ground where it falls. This can contribute to super-saturated soil and a wet basement.

Continuing the quest to find sources of supersaturated soil next to the basement, the slope of soil or mulch next to a house foundation should be an inclined plane leading down into the yard. If the soil surface actually slants down where it touches the house, rainwater will flow downhill and rest next to the basement wall. Not good.

Too much wetness in soil, from causes mentioned above or from an underground spring (especially annoying when your house sits on the top of a hill), is more than the normal basement is intended to bear. Water will push in where the floor and walls join or at the top of the walls or, truthfully, anywhere it finds a weak spot. This can be an expensive fix.

If your home has a wet basement, start exploring all these areas. However, unless you won the Powerball Lottery last week, consult with experts on how to prioritize the problems and start tackling them one at a time. Be strong. You can do it.

The author speaks from experience. She has a hard-knocks education in identifying and repairing a combination of causes contributing to basement water. However, like the Unsinkable Molly brown, she ain’t down yet.

Photo and text copyright 2012 Maren E. Morgan.