Is Your Yard Trying To Wreck Your Home?

How moisture affects your home’s foundation.

Your home sits on many different layers of soil, each with its own properties, including moisture content. These layers developed over a long time — billions of years, in fact. While some were carried there and deposited by water, wind or glaciers, the top layer was likely formed by the company that developed the land for your neighborhood. They removed soil from hills and put it into valleys to create a flat area ready to be built upon. This is known as fill soil.

Here’s the thing: Over time, soil, whether made by humans or nature, can become unstable. Drought can cause the soil to shrink and voids to form. Fill soil that was poorly compacted initially can compress over time. And lastly, large amounts of moisture can cause soil to soften or expand.

This is particularly true regarding the soil closest to your home. This is known as the “active zone” because it represents the soil most affected by moisture as the season or climate changes. Depending on the area of the country in which you live, the active zone may vary from a few feet to more than 30 feet below grade, and it typically extends as far as 10 feet away from your foundation. So, if the soil in this area becomes saturated with water from heavy rains or snow melt, your home’s foundation can sink or even fail. 

A structure’s foundation can sink and settle when the soil beneath it can no longer support it. If the soil under your home becomes saturated with water, it can soften and become unstable. (Think about stepping into a muddy field.) If you have a basement foundation, the soil surrounding it can become saturated with water and press outward due to a phenomenon known as hydrostatic pressure. Simply put, as water saturates the soil in the active zone around your foundation, the water exerts pressure against your walls. And if you’ve ever lifted a water cooler jug, you know how much just a few gallons of water weighs!

The importance of making the grade.

So, you can see why it’s so important to ensure that water drains away from your home’s foundation and past this active zone. To achieve this, the elevation around your home should drop one inch for every foot as you move away from the foundation up to 10 feet. This will help ensure that water drains away from your home and settles beyond this active zone by the time it starts to be absorbed into the ground. 

If you’re unsure if your yard is graded correctly, you can measure it with a few simple tools. You’ll need a 10-foot length of string, a couple of stakes and a bubble level. Place a stake into the soil right up against your home’s foundation and tie one end of your string to it right at ground level. Then, walk out 10 feet, place the second stake into the soil and tie the string around it. Make sure the string is taught and level. Now, measure the distance between the ground and the string ten feet away from your foundation. This will tell you how much your yard’s elevation has dropped 10 feet away from your foundation. Do this at several points around your home to get the best feel for your yard’s grading. If the numbers you’re getting indicate that your elevation drops less than one inch per foot, or if you find that the elevation hasn’t dropped at all, then it may be time to call a landscape company to grade your yard. 

Having your yard properly graded will give you the peace of mind of knowing that when heavy rains come, all that water is draining away from your home, not into its active zone, where it can cause all sorts of foundation problems.

Of course, if you’re worried that your yard’s grading (or lack thereof) has already caused issues with your home’s foundation, you should call a reputable foundation-repair company to inspect it. Because, even if your home’s foundation has already settled or has walls that have bowed or otherwise pushed inward, a foundation-repair expert should be able to fix the problem permanently, giving you even more of that precious peace of mind.