Why Do Basements Start Leaking Water?

Why Do Basements Start Leaking Water?

With all this rain, it’s definitely on the minds of homeowners who are dealing with a wet basement! Especially since you need to add a water rider to your insurance policy in order to get coverage for water damage inside the home because of a storm.

WHY DO BASEMENTS START LEAKING WATER?

Heavy rainstorms or a lot of melting snow can raise the groundwater level. This means for every inch of rain, a 1,500 sq. ft. roof sheds almost 1,000 gallons of water! This is a large amount of water.  Often, rain gutters and downspouts get clogged from fallen leaves and materials that wildlife leaves behind. New constructions have a problem with what is referred to as “reverse grading,” which usually occurs a few years after construction. This means the fill dirt around the foundation settles and directs rainwater right to the foundation.

As the runoff seeps through the soft topsoil around the house, it pushes against the walls and stops at the undisturbed ground just beneath the footings. Footing drains may break as the house settles, or silt up. If the soil is clay, water then starts rising in the disturbed soil around the foundation like inside a pool.

Hydrostatic Pressure – When condensation accumulates around the foundation, hydrostatic pressure builds up and causes the basement to leak. Clay-rich soils do not drain well and hold rainwater right against the foundation walls. Water pushes its way inside through any cracks or joints and the pores in concrete. Rising groundwater is sometimes the problem or even an underground spring. Houses settle and underground water flows change. New construction down the street may shift groundwater flows and cause basement leaks in your house.

Settling Cracks – As your home settles, concrete develops stress cracks that leak water. Exterior waterproofing disintegrates or separates due to the “alkali attack.” When water gets to embedded steel, it rusts, expands and cracks the concrete.

Efflorescence Signifies Water Seepage – Water penetrates into the pores in concrete, dissolves alkalis, and enlarges the pores. As concrete ages, it becomes more and more porous. Initially, the seeping water evaporates, leaving on the surface salts and lime. This “white deposit” or efflorescence is a telltale sign of capillary water seepage.

Plastic Barriers Do Not Last – Concrete slabs, although much thinner than basement walls get even less waterproofing protection. The plastic “vapor barrier” soon disintegrates due to the lime in concrete and over time, the layer of gravel (“drainage pad”) silts up. Then, the concrete starts pulling in groundwater by capillary action.

WHY EXTERIOR WATERPROOFING DOES NOT LAST

Tar Waterproofing Is Brittle – Tar waterproofing has no “give” and cracks as the concrete constantly contracts and expands, and as the house settles. Similarly, tar paper or pargeting (a layer of mortar) on block walls are inelastic and crack.

Concrete is “very strongly alkaline” (pH above 9). Water carries dissolved alkalis to its surface, where they attack any waterproofing coating by saponification (“alkali attack”) and even the concrete itself. Alkaline soils in some regions speed up this process and can “eat” away inches of concrete over several years.

All waterproofing coatings gradually break down or separate, even flexible elastomeric liquid membranes. Elastomeric sheet membranes separate as the alkalis attack the primer and taped joints — they are guaranteed for only 5 to 10 years.

In the end, the concrete is on its own! It may continue to do a good job for several years but water will gradually activate alkalis, leach out the concrete, and enlarge the pores, making water seepage inevitable. Water is the root problem — in perfectly dry conditions, concrete and waterproofing would last forever.

Stop water migration by internally sealing the pores and to neutralize the alkalis in concrete surface to protect the concrete and any waterproofing coating against alkali attack.

This can be done by Summit Environmental Solutions!

A proactive step that can be taken is regular maintenance on the sump pump. It is also a great idea to have a backup power source for the sump pump. Adding a second sump pump to the home is a great idea if you are dealing with water in the basement.

If you have a buried basement, keeping a dehumidifier running is practically a necessity. Moisture and dampness can be avoided by doing this, especially if your home is built on a piece of land with a high water table.

Inspect the basement foundation and the concrete floor for cracks and difference in color. If the concrete looks darker in color or feels cooler than usual it could mean water is seeping up through the floor. If there is a basement window, to prevent water from coming in, ensure there is a waterproofing system in place. Don’t forget waterproofing basement walls is important too. Summit Environmental Solutions has interior drainage systems to help stop water.

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