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Damp Clay Soil Beneath My House – Should I Be Worried?

Clay soils are expansive and can cause serious damage to your home’s foundation. Here are some tips to prevent structural damage.

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Foundation settlement is a common foundation problem especially for homes in Denver, CO, built on damp clay soils. These issues are usually due to the expansive nature of clay soils. Here, we look at how wet clay soil under your home affects you and what measures to mitigate the effects of clay on your home. 

damp clay soil

Understanding Damp Clay Soil 

Clay soil is a soft type of soil material that contains the smallest particles of all soil types. Although tiny, these particles quickly absorb water and expand in size. This expansion puts pressure on your foundation walls, causing them to crack or bow inward making them prone to water damage. 

Just as efficiently as it expands, clay soil also shrinks as it dries up since the particles release water to evaporation. When clay soil contracts, it creates gaps between the foundation and the backfill. These gaps give way to water, allowing it to run and settle at the base of your foundation. This water can find its way into your basement or crawl space, making it prone to water damage, mold, and pest infestation. These damaging movements put your home at greater risk of foundation damage. 

Effects of Wet Clay Soil Under Your Home 

Whenever it rains, expansive clay soils become saturated with water. The soil becomes muddy and unable to bear the weight of your home. As a result, your home may settle into the ground resulting in the clay bowl effect. 

The clay bowl effect is a phenomenon that occurs due to the natural consequences of digging out a hole and backfilling it with soil when building a foundation. Backfill is the material that is put back into the hole dug during the construction of the foundation. When backfill material consists of more clay soils, the clay bowl effect may arise. Generally, clay soil is more porous and more absorbent than the hard-packed virgin soil around it. 

So, when it rains, the ground closer to and under your foundation becomes more saturated than the undisturbed soil surrounding it. With time, the soil surrounding your house starts to settle, creating a bowl-like effect. This alters the original slope of the house and affects drainage. 

How the Clay Bowl Effect Affects Your Property 

The change of slope causes water to pool around your foundation. This water slowly siphons into your basement or crawl space through gaps, cracks, and porous foundation walls. Also, this water leads to the formation of cracks due to the water in your soil exerting hydrostatic pressure against your walls. 

Mitigating the Effects of Clay Soil 

Damp clay soil is a powerful destabilizing force on residential structures. Left untreated, it can do immense damage to your home’s foundation, walls, and other important features. The following suggestions are essential to mitigating the effects of expansive soils on your foundation. 

Maintain constant moisture content: Expansive clay soils cause the most damage when there are substantial changes in the moisture content of the soil. Maintaining constant soil moisture levels in the clay soils around and beneath your foundation is an effective way to prevent or reduce the effect of damp clay movements on your structure. During the dry periods, you can control moisture balance by watering the soil using a sprinkler or soaker hose. 

Control runoff: When living in a house constructed on wet clay soils, you must make sure the drainage conditions around your home are monitored and maintained annually. Maintain the grading around the foundation to slope away from your home. This way, surface runoff always flows away from your home and does not stand or pool beside your foundation. 

Clean and maintain your gutters: Without functional gutters and drainage, rainwater pours and collects at the base of your foundation. Eventually, this water ends up in your basement or crawl space. If you already have gutters, make sure to keep them clean and free of debris so they won’t clog and overflow. Add downspout extensions where necessary so the gutters drain the rainwater at least four feet away from your foundation. 

If you are concerned that the damp clay soil under your home in Denver, CO, could destabilize your foundation, contact the professionals at Complete Basement Systems for a free foundation inspection. We will evaluate the nature of your foundation and the extent of damage and offer solutions to help stop further deterioration. 

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Palmer Lake, CO 80133

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Denver, CO 80216