Grading your foundation area for adequate home drainage
Let’s talk about the grade of your foundation area. I don’t mean whether you give the contractor an A,B or C on the work. I mean the degree of slope the ground conforms to as it slopes away from the foundation stem wall. Grading of the foundation area greatly enhances a hand excavated french drain with respect to groundwater removal.
While city and county planners recommend a slope of at least 6″ per 10 lineal feet away from the foundation for a healthy home groundwater drainage grade, you will be served well to have in excess of this grade.
The groundwater removal that you can enhance by raising the grade at the foundation stem wall with a greater foundation grade is significant. This is especially true if clay or dirt is compacted into a splash block, and not dug up with plantings on the foundation for a distance of approximately 18″-24″ from the foundation wall.
Sacrifice form for function, with respect to your gardening desire in this area, and your home drainage results will be greatly increased.
The addition of a hand excavated french drain with a slope of approximately 2″ per 10 feet of grade or greater with a hard flat surface that is installed at the bottom of a tapered splash block, that slopes away from your foundation, will most often prevent groundwater entry to your basement or crawlspace.
Areas that require special treatment and are rare groundwater problems are homes where the entire foundation area has been backfilled with rock after the foundation was poured, and right on the foundation wall as well, in which case additional home drainage methods can be attempted to deter the groundwater from running through the rock, but this makes for additional problems in groundwater removal because the groundwater runs right through the rock below grade. Read additional articles on this subject in this web site.