Grading is fundamental to preventing water intrusion into a structure. Even a home built on a hilltop will experience penetration issues if the grade closest to the house is negative. Accepted standards call for a slope of 1″/foot for the first 6′ next to a house. You must look past the mulch and gravel that are common on houses presented for sale; water passes freely though them. It is the slope of the soil that matters.
If it looks like water will flow towards the house, it probably will. Sometimes the site will not allow for a positive slope throughout. A “swale” or culvert will be needed to catch the surface water before it reaches the house and carry it away. Don’t ignore drainage issues not adjacent to the house. A lake in the backyard makes it unusable, and is a breeding ground for mosquitoes. You must make note of the features and concerns you see on the exterior, and connect the dots when you’re inside. Bad grading is rarely present without consequences.
The final grading or landscaping at the property is not complete. This can allow water to accumulate at the structure and cause water penetration through the foundation. Monitor the grading upon completion, preferably during a period of heavy rain. The grade should be sloped at 1″ per foot for up to 6′ from the dwelling.
The grading is sloping towards the foundation. This will permit water penetration. Regrade to divert surface water away from the foundation. The grade should be sloped at 1″ per foot for up to 6′ from the dwelling.
The grading is eroded next to the structure. This permits water to collect and penetrate the foundation. The cause of the erosion should be identified. Correct any issues causing the erosion, and regrade to divert surface water away from the foundation.
The landscaping features appear to block proper drainage around the structure. This increases the potential for water to collect and penetrate through below grade foundations. Remove or relocate the landscaping feature.
There are deep cracks in the soil of the yard. This implies the need for a swale or drain to improve drainage and prevent surface flooding or penetration into the house. Regrade or install a swale to divert surface water away from the property.
There is standing water in the yard. This affects the yard’s usability and creates a condition conducive to mosquito breeding. Regrade to divert surface water away from the property.
The swale is damaged or eroded. This can divert surface water runoff towards the structure and allow water intrusion into the building. Regrade the swale to divert surface water away from the foundation.
The swale does not appear to be effectively diverting water away from the structure. This can result in water intrusion through the foundation. Regrade the swale to divert surface water away from the foundation.
