How To Measure Slope Around a House Foundation

A properly graded yard should slope away from your foundation so rainwater and snowmelt can flow away. If moisture pools near the foundation walls, it could lead to issues such as flooding and leaking, mold growth, soil erosion, and water damage.

Experts recommend a slope of at least 6 inches over the first 10 feet extending from the foundation. Here’s how to measure your yard’s grade so you know where your home stands.

Materials and Tools

Here are the items you need to measure your grading slope: 

• Two wooden stakes
• 12 feet of string or twine
• Hammer, mallet, or ax
• Line level
• Tape measure

Step-by-Step Instructions

Follow these steps carefully for an accurate measurement.

1. Hammer a stake firmly and securely into the ground next to your home’s foundation and as close to the house as possible.
2. Tie one end of the string around the top of the stake at ground level. Leave enough slack so you can pull the string taut later.
3. Use your tape measure to measure out exactly 10 feet from the house foundation, and firmly hammer the second stake into the ground at this point.
4. Attach the loose end of the string to the top of the second stake, again leaving some slack.
5. Pull the string tightly from both stakes to form a straight line.
6. Place the line level at the exact center point of the string. Adjust the string’s position on the second stake until the line level shows the string is perfectly level.
7. Once the string is level, measure the distance from the string down to the ground with your tape measure. This is the slope measurement.
8. Record the slope measurement in a notebook or land survey document and repeat the process around your whole house’s perimeter. By measuring the slope in several spots, you can more accurately determine your yard’s drainage patterns.

There should be a 6-inch difference between the string and the ground for proper drainage. If the ground is less than 6 inches below the string, the slope is too gradual.

Tips for Accurate Measurements

To ensure the most precise grading slope measurements, keep the following tips in mind:

• Calibrate the level: Calibrate the line level properly before taking measurements.
• Keep everything straight: When hammering stakes, make sure they’re perfectly vertical, not slanted. Pull the string between the two stakes as tight as possible for an accurate reading.
• Check and double-check: Take multiple readings from the taut string to the ground and average them for better accuracy. 
• Remeasure as needed: If you make any changes to the yard’s grading, recheck measurements to confirm there is still a proper 6-inch slope.
• Measure through the seasons: Taking measurements in different seasons can help you account for changes as the soil compacts and expands during freezes and thaws.

Solutions for Improving Drainage

If measurements reveal that the ground is too flat or slopes downward toward the foundation, there are a few ways you can improve your yard’s drainage.

Regrade the Soil

The most direct and decisive solution is to have an excavation contractor add or remove enough soil to create the ideal grade and then smooth everything to the proper slope. The contractor can help you choose a soil type that promotes good drainage and compacts the soil down adequately so the slope stays firm. 

Regrading often requires heavy equipment, precision, and expert knowledge. It may be more expensive, but it’s a worthy investment for your property’s long-term health.

Install Swales

Swales are sloped trenches lined with grass, gravel, or rocks that redirect water flow away from the house. While they aren’t as optimal a solution as regrading, they can be effective in problem areas. You can build garden beds, moisture-loving plants, and decorative rock features around them to integrate them into your landscape design.

Add French Drains

French drains are perforated underground pipes around a home’s perimeter that capture water and move it away from the foundation. They’re particularly useful if your home has persistent drainage issues. However, it’s important to cover them with permeable landscape fabric so soil and debris won’t clog them up. 

Extend Downspouts

Downspout extenders move roof runoff further away from your home’s perimeter. Different designs are available that can blend in with your gutter system or exterior. If you’re environmentally conscious or want additional drainage, you can pair downspout extenders with gardens or rain barrels.

Add or Improve Gutters

Make sure your gutters are properly angled to keep water runoff away from your foundation. If your existing gutters don’t handle water flow from your roof sufficiently, consider upgrading to larger ones that offer better water management. A set of gutter guards can also keep water moving by preventing leaf and debris buildup.