Floor seepage (hydrostatic pressure)

Basement floor seepage or “ground water” is caused by hydrostatic pressure. It occurs when water accumulates under the home causing the water table to rise and put upward pressure on the basement floor. If you have floor seepage it will typically show itself seeping through the “cove joint” of your basement or crawlspace. The cove joint is the spot where the concrete basement floor meets the vertical foundation wall. Since the floor and the wall are poured at separate times there is a small void that water comes up through. This pressure can lead to a range of problems, including floor cracks and in rare occasions even structural damage. 

Causes of Basement Floor Hydrostatic Pressure

The primary cause of basement floor hydrostatic pressure is excess water around the foundation of a home. This excess water build up will run down the foundation wall underneath the home until it hits clay soil (The beginning of your homes water table.) Heavy rainfall, snow melt and spring thaws increase the amount of water around and under your home. Other factors such as poor yard drainage, and underground springs also contribute to water underneath your home. Once this water starts building up underneath your home it will eventually reach your basement concrete floor and begging pushing up against it. This pressure will force water up through any cracks or openings in the floor.

-Preventing and Repairing Basement & crawlspace ground seepage

WHAT CAN YOU DO?

There are a few basics homeowners should focus on to help reduce or alleviate the possibility of hydrostatic pressure.  Always make sure your gutters are clean and downspouts are extended a minimum of 6 feet from the foundation wall. These two practices ensure that you are keeping unnecessary water away from your foundation. Another focus for homeowners is the soil grading of their lot. Positive soil grading is important as a slope away from the home will keep water away from your foundation. If you have negative soil grading you should consider installation of a French drain which is a shallow trench along the wall, pitched to redirect water away from your home.

What can we do?

If the basics still do not solve your basement ground seepage you will need to get a drain tile system installed. A drain tile system is an interior drainage system which captures ground water and routes it to an 18×22 sump pit basin. Inside the fiberglass basin we install a ½ horsepower cast iron sump pump to eject the water outside your home. A drain tile system is installed underneath the concrete slab of your basement and runs along all exterior walls. The drain tiles are now the new low point for water to access before it is able to reach the concrete floor.

– DRAIN TILE INSTALLATION:

1. Breakout concrete along exterior walls approximately 8-10 inches from the foundation wall.
2. Next a 9 inch deep trench is created by digging out the existing clay and dirt.
3. After trenching, a pit will be dug out to place an 18×22 sump pit basin containing a ½ hp sump pump. The pump is connected to a 1 ½ inch pvc discharge line extending outside your home  to eject any ground water that enters the basin.
4. After the trench is sloped towards the sump pit basin a 4 inch perforated drain tile protected by a filter sock is installed in the trench and directed into the sides of the sump pit basin.
5. The Drain tile is then surrounded by pea gravel to keep any debris from entering the drain tile possibly causing a clog.
6. Drainage board is an optional feature typically only used on cinderblock foundations to capture any seepage coming through the wall.
7. Next, a new 3.5 – 4 inch concrete slab is poured on top of the trench and smoothed out with a hand troweled finish.

We have many customers that claim the drain tile system is a life changing addition to their home. If you pay for a home with a basement or crawlspace you should be able to use it however you would like. Our drain tile systems also carries a lifetime, unlimited transferable warranty. Having a good warranty is key when putting your house on the market giving the possible buyer peace of mind.