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Water Infiltration (part 1)

As we all enjoy the changing color of the leaves in the Fall, some homeowners begin to dread the rain that also arrives with the season change.  Water infiltrating the home becomes a problem all homeowners start to fear.

There are four common sources of water entering a home:

       • Surface water running down foundation walls;

       • Groundwater in water-saturated soils being pushed into the basement by hydrostatic pressure;

       • Storm sewer water from the municipal storm sewer system backing up into the home's existing  

         perimeter foundation drain and leaking into the basement;

       • Sanitary sewer water from a clog in your home’s sewer line, the municipal sewer line, or the combined municipal storm/sanitary sewer system backing up into the home's drain system, causing sewer water to come up through sink drains and floor drains on lower levels.

Given that this problem is a costly and important issue to any homeowner, one article will not do it justice. For this article I will discuss the first 2 points, Surface Water and Subsurface Groundwater.

Surface Water

If this is the first instance of water problems in your basement, the first thing to check for is surface water draining down next to the foundations. Water coming in at one location or only at the exterior foundation wall indicates surface water problems. Things to look for:

Overflowing Gutters: Leaves

Keeping gutters clean of debris should be a part of every homeowner's routine maintenance program. Depending on the surrounding trees, gutter cleaning may be required a few times a year. Products are also available to prevent leaves from getting into the gutters in the first place.

Overflowing Gutters: Downspouts

Do a self-check (your gutters must be cleaned out first). After at least 15 minutes of heavy rain, check your gutters. If you see any water overflowing, you have a problem. Any water overflowing out of the gutters is running down next to the house foundations. Even if the water is not getting into the basement, it could be eroding soil from under the house footings, which can lead to cracking of walls and ceilings.

Downspout Distance

Downspouts should extend 6-10 feet from your home. While many homeowners do not like downspouts extending out this far, 6 feet is the minimum distance needed to discharge water coming off your roof to ensure the water is far enough away from the house.

Pavement Slope

Sometimes paving settles over time and water flow can change direction toward the house. If this is the case, the paving should be removed and replaced so it slopes away from the home.


Sealant around pavement that abuts the house sometimes cracks over time due to age or incorrect installation. If the sealant is cracked, it must be removed and replaced with new sealant.

Landscape Slope

Does your yard or the land around your home slope away from your home? It should. This is called positive grading. And land that slopes towards your home is called negative grading. Look for any depressions in the ground next to the home foundation walls. If any are found, fill them in with dirt so the water drains away from the house. Use a clay-type soil that sheds water instead of sandy soil that allows water to soak into the ground. Make sure that at least eight inches is kept between the top of the earth and any wood or stucco on the house. If there are large hills nearby sloping toward your home, and you think they may be causing the problem, this could also be a Swale that diverts water around your home.  A civil engineer may be required to analyze the situation and determine the appropriate solutions.

Subsurface Groundwater

If no surface water sources are found, then the source of the water is likely subsurface groundwater under hydrostatic pressure. Unfortunately, subsurface groundwater problems are more difficult and more expensive to fix than surface groundwater problems. When the groundwater levels outside the basement rise above the level of the floor, the basement acts like a boat in a pond. If a boat is sitting in water, water will leak in through any open cracks or holes. It works the same way with a basement. Hydrostatic pressure can push water through hairline cracks. Symptoms of this are water coming up through cracks in the basement concrete floor or water coming in at multiple locations. If you have an older house within town and the house has a basement with no sump pump, it is likely the perimeter foundation drain system connects directly into the city storm sewer system. If the level of the basement is below the street level, there is the potential of storm water backing up in the city storm sewer system and being pushed into the perimeter foundation drain system. This can saturate the soils around the house at the basement level with storm water under hydrostatic pressure, causing water to leak in.

Each source has its own particularities and requires its own course of action.

I Recommend consulting a contractor or plumber.

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