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Hydrostatic Pressure and Effects of the Water Table


Wet basement walls, foundation cracks, flooding and water damage are common problems experienced by many homeowners. These problems are especially common in older residences that haven’t been properly serviced in several decades or are located high in the water table.

As homes age, the basement waterproofing systems in place become less effective and the block walls of your basement foundation begin to crack and degrade. The number one cause of this is moisture absorption and hydrostatic pressure surrounding the foundation walls.

Because older homes were often waterproofed using methods and materials that are now outdated and ineffective, you may find yourself having to excavate around your basement walls to reinstall more up-to-date systems. 

Basement Solutions provides just that with our professional experience and extensive waterproofing services.

What is Hydrostatic Pressure?

A majority of the basement and foundation water damages are caused by a something called hydrostatic pressure. It occurs as the soil around and under your home’s foundation becomes saturated with rain and groundwater. This creates an immense amount of pressure against the walls and floor as the water level rises. Consistent pressure has its effects slowly over the years and begins to show through cracks, leaks and bowing walls. The amount of rainfall in the Greater Philadelphia region and the east coast as a whole make it specifically prone to these problems.

Another side effect of hydrostatic pressure is the slow absorption of moisture into the porous blocks of your basement walls. Water moves from the soil into the pores of the walls and causes damage that will eventually make its way to the interior of the basement.

Although some polymer based coatings such as Block and Wall Liquid Rubber when applied to the outside of the wall will prevent absorption, the best way to stop this process is with the proper Basement Solutions waterproofing system.

Effects of a High Water Table

Structures that enter the ground should almost always be waterproofed.  Additionally, if the structure is located in a place with a high water table, waterproofing is not only necessary, but it must be performed by expert professionals. 

What exactly is the water table anyway? The water table is the boundary between the unsaturated zone and the saturated zone underground. Below the water table, groundwater fills any spaces between sediments and within rock. A number of factors can force the water table to go up or down.

Every time it rains, for example, water trickles down through layers of soil and raises its water table. Runoff from lakes, rivers, and streams also contribute, along with melting snow. The rock around the water table must be porous so that it can be saturated with water.

The level of a water table fluctuates depending upon environmental conditions as well. Seasonal dryness and tidal changes, as well as human interaction can also have an impact. A drought for example, can cause it to drop significantly, and heavy rains can cause it to raise.

Basement flooding and foundation issues often occur when the structure is located high in the water table.  The resulting increased hydrostatic pressure on the floor and walls of your basement make it susceptible to leaks and cracks.

Helpful Tips

Waterproof your basement floor and walls. There are many ways to do this and the approach depends on the needs of the space, but this is essential in keeping moisture out. We offer extensive solutions to fit your exact needs and desired cost.

Install a draining system.  This will provide some relief to the hydrostatic pressure building up around your foundation.  Drain systems can be both internal or external, but a combination of both is usually ideal. Yard drainage systems, french drains and interior/exterior drain tiles are just a few of the options.

Install a reliable (preferably high volume) sump-pump system with a battery back up. Sump-pumps are relatively inexpensive but can be very beneficial in the long-run, especially in areas that flood frequently.

Call a professional!  Have someone like ourselves evaluate your basement and discuss the issues with you. Attempting to make this issues DIY projects will only create further issues. The integrity of your foundation and the health of your family should come first!

Contact Us

With further questions or any of the previously mentioned issues, give us a call today at 610-495-9111 for a FREE INSPECTION or visit www.basements911.com for more detailed information on our services.