Landscape Grading & Water in your Basement

1/18/2018 (Permalink)

It's hard to imagine right now, but spring will be here before you know it.  And while spring may be a welcome sight for many of us, it isn't without it's problems.  Many of you will find wet foundation walls or even water in your basement during the spring thaw.  There are a couple of reasons why this might happen.  One of them is something many of us never think about and that's the grading of our yards.  

According to Wikipedia, "Grading in civil engineering and landscape architectural construction is the work of ensuring a level base, or one with a specified slope for a construction work such as a foundation, the base course for a road or railway, or landscape and garden improvements, or surface drainage."

It is important that the ground around your home slopes away from your foundation so that water, or surface drainage, from heavy rains or melting snow, runs away from your foundation and your home.  Ground that is flat or slopes toward your foundation is a recipe for wet basement walls or water in your basement.   

Proper slope and surface drainage is something that should be checked periodically.  Ground shifts and settles with freezing and thawing, erosion and other impacts of nature.  Settling ground is particularly pronounced in newer homes where the ground has recently been disturbed to build the home.  The ground will compress or settle downward.  Evidence of this will be more visually apparent in sinking walk ways or patios, but may not be as obvious in the ground around the foundation of the home as it is often hidden by shrubs and plants in landscape beds.  It's important to check for proper slope every year or so and fill in with dirt if necessary to help keep your foundation walls and basement dry.

What is the proper slope away from your foundation?  The consensus seems to be 6 inches for the first 10 feet extending out from your foundation.  This translates to a slope of 5%. According to the Spruce,  

"To find the slope away from your foundation, you will need:

• Some string (at least 12 feet long)
• 2 stakes (we will call them "A" and "B"), and something to pound them into the ground

• A string level (that is, a type of level designed to fit on a piece of string)
• A tape measure

Do You Already Have the Correct Slope?

Using the above supplies, take the following steps to determine if sufficient slope currently exists:

1. Tie one end of the string loosely around stake A.
2. Pound stake A into the ground right near your foundation
3. Slide the string down stake A, so that it rests at ground level
4. Tie the other end of the string loosely around stake B.
5. Now measure out 10 feet down the slope from stake A, and pound stake B into the ground there (if there is excess string, just wrap it around stake B). The string between the stakes should be fairly taut, but still adjustable.
6. Slide the string up or down stake B, so as to make it roughly level.
7. Put the string level on the string, at about the mid-point between the stakes.
8. Now adjust the string up or down on stake B, so as to make it exactly level.
9. Measure the distance from the string on stake B to the ground. Is the measurement 6 inches or more?" 

And if you do find yourself with wet foundation walls or a wet basement, SERVPRO of Appleton is always here to help.