Negative Grading

Problem

As any home inspector will tell you, water damage presents the single biggest threat leading to costly repairs of your home. The American Insurance Association reports that water damage claims have grown faster than any other type of claims, with approximately 20% of all claims. Despite the prevalence of water-related problems, homeowners often struggle to pinpoint the true cause of these issues.

Often, a major root cause of water intrusion comes from poor grading around the home. Positive grading means the ground slopes away from the house, carrying water away from the foundation, while negative grading slopes towards the home, directing water toward the foundation, causing the water flow to accumulate at walls, particularly around window wells, steps, and downspouts.

While negative grading could be a result of poorly designed grading and drainage systems during construction, often it’s a result of the inevitable settling of the soil over time. Maintenance of the grading around your home is simply a reality of homeownership and one that shouldn’t be ignored.

Effects

The impacts of negative grading and poor lot drainage can be severe, with water pressure building over time and exerting force on a home’s foundation. This pressure can cause dangerous horizontal cracking, foundation movement, and costly repairs in poured concrete foundations. Block foundations are vulnerable to cracking, leaning, and holding water for extended periods, leading to damage and mold in the wood framing above. Negative grading can also contribute to basement water seepage, damaging finished spaces and furniture within the home.