Yard Grading For Foundation and Waterproofing Repair Work and Yard Regrades for Drainage Management
These grades are guidelines and not hard and fast rules. A survey of the project should be done before work or grading starts and variances from the optimum or the minimum should be set out by, or discussed with the production department.
Siding- (figure 1) clearance below siding should be 6” or more, but in cases where other existing conditions (extreme cases such as sidewalks, misc obstructions, and total lot slope, etc) will not allow the 6”, a minimum 3” would be acceptable
Brick- (figure 2) clearance below brick should be 4” or more with a minimum of 1” for extreme cases.
Note- new construction (room additions, new homes, etc) must have a 8” clearance below the siding (city code).
SLOPE AWAY FROM HOUSE:
Below Grade Specs- (figure 3) the surrounding grade of spaces below grade (basements, crawl spaces, etc) should slope 8” or more in 6’ with a minimum of 6” in 6’ for extreme cases.
Grade Level Spaces- (figure 4) the surrounding grade of foundation walls and concrete slabs that are adjacent to the below grade space or that are at or below the floor level of the below grade space (porches, garages, walks, patios at walkout masements, etc) should be no less than 6” in 6’ with a minimum of 4” in 6’ for extreme cases.
Slope Beyond 6’– The grade beyond 6’ to 12’ out should be ½” per foot or more with a minimum or ¼” per foot in extreme cases. The grade beyond 12” should be ¼” or more per foot with a minimum or 1/8” per foot in extreme cases.
PLANTING BED WITH MEMBRANE:
Grade- The slope on a planting bed should be 1” per foot or more with a minimum of 1/2” per foot for extreme cases.
Membrane Installation- Install a membrane consisting of a double layer of 6 mill or one layer of 10 mill poly film, from the foundation or slab to the area where a tight grass cover will be maintained. Turn the poly up on, and keep it tight to the foundation or slab, and seal any joints in the poly with mastic. Install the planting through the poly or install the poly around the plants. Apply bark or other mulch. If an angular rock mulch is to be used, apply approximately 1” or sand before placing the rock. If there are edgings around the mulched plantings, be sure openings are made to thoroughly drain the planting area.
Gravel driveways should slop 6” from the door in the first 8’
Splash Blocks– Install a 3’ minimum length splash block at gutter downspouts.
Pipe Drains- Install pipe drains with a slope of ¼” per foot or more with a minimum of 1/8” per foot in extreme cases. Install a removable drain screen or gutter connector on the inlet and a rodent barrier screen on the outlet.
FINE GRADING AND SEEDING:
Top Soil- Spread approximately 1” of top soil over harsh and barren sub soil clays.
Fine Grade- The final grade should not be smooth, but it must be “true” with out pockets and humps. The surface may contain clods to 2” in size.
Fertilizer- Apply approximately 2 lbs of fertilizer per 100 sq ft.
Seeding- Apply approximately ¾ lbs of seed mix per 100 sq ft lightly raking into extremely smooth areas.
Mulch- Apply approximately ½ bale of, well torn apart and distributed straw per 100 sq ft.
Watering- Hose down straw enough to dampen and matt down.
Throughout 2011 we have seen a large number of failed waterlines leaking at the foundation due to dry soil conditions causing the clay to shrink and rupturing of the line. Make sure to water your foundation during the long dry spells of summer to prevent this.