What are the problems with negative grading and how do I fix it?
• Grading or slope of the land is important around the home because it will determine which direction surface water will flow. Negative grading is when that surface slopes towards the foundation wall. This can allow surface water to run directly against the wall and potentially seep into the basement or crawlspace. Regrading the area around the foundation walls repairs the majority of the basement water penetration problems. Many problems occur when people install flower gardens or put mulch up against a foundation wall. In order to properly fix a negative grading condition, the top, porous soil must be removed in the affected area and well-compacted, non-porous clay or similar soil must be added and re-graded. The newly added soil around the perimeter of the home should slope away (at a minimum rate of one inch for the first 6 feet) from the house to prevent rainwater from accumulating next to the foundation.
