In over 2,400 inspections, I consistently find one defect 95% of the time, negative grading. Negative grading is when the soil around your home is sloped towards your foundation, most foundation and water problems can be directly connected to negative grading causing hydrostatic pressure against the foundation.
Hydrostatic pressure is the water pressure against your foundation, water weighs slightly more than 60 lbs. per cubic foot. If the soil around your foundation is saturated with water, there could be tens of thousands of pounds of hydrostatic pressure against the foundation wall. This makes it likely that water will find its way into your basement, as well as causing foundation problems with cracking or bowing.
Repairing negative grading usually is relatively inexpensive and easy to correct but needs to be done correctly or there may be more harm done than good. But if the the driveway, patio or sidewalk is causing the negative slope the repair will be much higher and may require professional services.
Here are several examples of what I find that looks good as I walk up to the home but upon further investigations may be causing problems:
- Rock being used for grading
- Mulch used for grading
Using rock or mulch is deceptive in promoting what looks like a positive or proper grade of soil. Remember mulch and rock sits on top of the ground surface, water will sit in the rock and mulch is to retain moisture, think “giant sponge”. Rock and mulch can be used for cosmetic purposes after the grading is done correctly.
I recommend that homeowners use black dirt to grade 1/2 inch a foot for the first 10 feet away from the foundation or 1 inch a foot for 6 feet away from the foundation to have proper run-off of water away from the foundation. This may require removal of concrete, asphalt, plants or shrubs. After achieving the correct slope you may replant the shrubs or plants.
In the event that your yard will not allow positive drainage, then you may have to dig down and install a swale or French drain to divert the water away from the foundation.
Gutters and downspouts are another extremely important element in water control. Keep gutters clean and downspout extensions in place (6 feet or more). Paint the inside of galvanized gutters, which will extend the life. Shortly after a rain or thaw in winter, look for leaks at seams in the gutters. These can be re-caulked before they cause damage to fascia or soffit boards. If no gutters exist, it is recommended that they be added.
Water is a great force many people underestimate, but causes the most harm to our homes, with a little forethought and planning these problems may be avoided.