Minimum Grade from Foundation Walls
A sloped surface is required to effectively drain water away from the foundation walls including areas under steps and decks. This will greatly reduce the risk of surface water entering the basement during rainfalls or snowmelt.
Minimum Grade Requirements
- 10% for first 2 m. Minimum 20 cm drop for soft surface / landscaping (eg. clay, topsoil or sod)
- Minimum 15 cm drop for a side lot less than 1.5 m for soft surface / landscaping (eg. clay, topsoil or sod)
- 0.75% for hard surface or other impervious surface treatment (eg. concrete or asphalt)
Or, for a side lot less than 1.5 meters, provide a 15 cm drop away from the foundation wall.
Grading Examples
The following pictures illustrate the proper grades around the foundation wall:
-
Backfill Under a Front Step -
Exterior Deck Skirting Removed to Backfill Under a Front Deck -
Pre-grading Backfill for a Future Front Deck -
Well Graded Window Wells with Swale -
Well Graded Window Well -
Good Rough Grade under the Future Deck -
Good Rough Grade along Foundation Wall -
Good Rough Grade between Houses -
Good Final Grade between Houses -
Hard Surface Grading
For More Information
Drainage Planning and Engineering
5th Floor, Century Place
9803 - 102A Avenue NW
Edmonton, AB
T5J 3A3
| Telephone | 311 or 780-496-5576 |
|---|---|
| Fax | 780-496-2865 |
| lot.grading@edmonton.ca |
