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

Foundation Wall
  • 10% for first 2 m. Minimum 20 cm drop for soft surface / landscaping (clay, topsoil or sod)
  • Minimum 15 cm drop for a side lot less than 1.5 m for soft surface / landscaping (clay, topsoil or sod)​​​​​​.
  • 0.75% for hard surface or other impervious surface treatment (concrete or asphalt)​​​​
Garage Wall
  • Provide a minimum 5% slope away from the wall for a distance of 2 m or provide a 10 cm drop to the common property swale​​​​​​​ if there is insufficient space to provide a 2 m gradient

Grading Examples

The following pictures illustrate the proper grades around the foundation wall: