Wet Basement Drainage
Keeping Your Home's Feet Dry
How to dry out existing wet basements, fix foundation leaks, waterproof foundations, and keep new basements from ever getting wet.
Water, an unwelcome guest in any basement
Wet basements seem to be one of the major problems plaguing many homeowners according to most home repair forums. If you happen to be one of those folks blessed with an unwanted indoor swimming pool each spring, whether in a new or more "mature" house, rest assured that something can be done to solve, or at least, reduce your problem.
For over forty years I've been working with water in one way or another — finding it, getting rid of it, and keeping it from doing harm to something else. From providing earthwork for new homes in difficult sites to helping solve existing foundation related problems, controlling water has always been a high priority.
During these years the most curious situation I've seen occurred at a house just up the street from my own where the well went dry before the basement did! Don't let this sort of thing happen to you. Take advantage of my years of experience by purchasing and reading this article and putting its proven techniques to use yourself whether you are building new or remodeling an old farmhouse.
The flooded basement shown above shows the effect of a High Water Table. Although this basement did have an exterior perimeter drain, water was still finding its way up through cracks in the floor and next to the wall. I corrected the situation by adding drainage under part of the slab and tunneling under the wall's footing to connect the new interior drain to the exterior pipe already in place.
This document can be purchased for a nominal fee and downloaded as a PDF file, readable and printable through Acrobat Reader. Scroll to the bottom of the page to purchase now, or read the following introductory section before taking the plunge.
Before "digging" into this site, you can look at photos of several of my past jobs. Each photo has
to do with water showing up in places where it should not have for
one or more of several different reasons. Note that each photo depicts a problem that
has been solved, so be reassured that your problem likely can be as
well. Click here to view the photos or start reading the beginning of the article below...
Keeping Your Home's
Feet Dry
Every D-I-Y magazine runs articles in the Spring describing new miracle products that allegedly stop water from entering through a basement wall or floor. Some products may be effective at stopping surface water from coming through cracks or flaws in a wall, but I've always figured that trying to hold out groundwater is like trying to keep water from leaking through the seams of a boat. As long as any part of the boat is in the water, a certain amount is bound to leak in.
The big disadvantage of waiting until water enters the basement before pumping it out is that the resulting dampness can be both distasteful and dangerous, even if there is no noticeable standing water. Just as constantly wet feet would not make you comfortable or allow you to remain healthy for very long, neither can your house survive that condition for extended periods without damage.
FIRST THINGS FIRST... Before tackling a wet basement it is necessary to know the source of the water. Click here to see the Basement Drainage Checklist that you can use to review your own situation before going through the following Guide.
Determining the source...
A Troubleshooting Guide
There are essentially four ways that moisture can enter and collect in basements:
- Leaky plumbing supply or waste lines or fixtures.
- Surface (rain) water leaking through openings or flaws in the walls
- High groundwater table
- Condensation
A. Eliminate the possibility of leaks from any and all plumbing fixtures and piping inside the house and also the domestic (drinking) water supply line. This line can enter through the basement wall or through the floor and sometimes can run for some distance under a basement floor. A leaking water supply line will generally create a constant appearance of water, often near, but not limited to, where the water line enters the basement. Shutting off the supply line can usually stop water from leaking if it is from a public water supply. Observing increased electric use and/or running time of the well pump for a house with its own deep well water system (pump in well) can often provide a tip-off to a broken water supply line as can shutting off the pump to see if the leak stops. See Wrong Culprit See section: 1.1 PLUMBING LEAKS
B. If water appears during or immediately after a rain or snow melt event, especially if it is coming through the basement wall(s) well above the floor, it is likely that the problem is inadequate wall waterproofing, and poor surface drainage away from the house. Roof water likely concentrates next to the wall and finds its way through flaws. If the water stops coming in shortly after the rain or snow melting stops, this generally confirms the diagnosis of surface water entering. See section 1.2 SURFACE WATER ENTRANCES
C. If water appears through cracks in the basement floor and/or around its perimeter where the walls join the floor sometime after rainfall or snowmelt, and remains for some time, the problem is likely to be a high groundwater table [link to septic glossary]. In some places a high water table can persist for weeks, months, and occasionally year round, requiring the installation of a drainage system that actually lowers the water table under and around the house. Many times an adequate de-watering system may have been installed when the house was built or sometime afterward, but, because of carelessness or neglect, the system has failed to function simply because the outlet of the pipe has become plugged with leaves, roots or other debris. Occasionally, simply locating and unplugging the end of the pipe can be all that's necessary to effect a cure. See: 1.3 GROUNDWATER, THE RISING TIDE
D. Condensation often occurs in crawl spaces and basements with either dirt or concrete floors where there is inadequate ventilation, especially if the floor level is near the top of the water table and/or the soil is poorly drained clay or loam rather than sandy. It also occurs in basements of homes that are shut up for much of the year and occupied only when the hot, humid air of summer days is suddenly allowed into the inadequately ventilated basement. The moisture carried by the hot air condenses on cool concrete, stone, metal and even wood surfaces in extreme cases, and often remains trapped because there is not enough air movement during dryer days to evaporate the condensed moisture. This is a common occurrence in vacation homes, especially when they are in heavily wooded areas with little sun and air drainage.
Condensation can also be a by-product of either a high water table or surface water entering and being trapped in the basement, then evaporating and re-condensing onto any and all basement surfaces, eventually causing severe damage to the structure.
E. It is very possible that both surface and ground water is entering the basement which will require following the recommendations in both sections 3.1 and 3.2 (see outline below) for total success. In many cases it is also likely that extremely high levels of humidity have ensued from surface or ground water flooding, and it is possible that, by controlling the unwanted water, the excessive dampness may be eliminated. Be aware that every situation is very different and requires careful examination to determine the true cause of the problem so that the correct path to a solution can be chosen.
