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 final landscaping.
•0.75% for concrete, asphalt or other impervious surface treatment.

Grading Examples

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

Poor Rough Grade on the right side generates a

high risk of basement flooding

Major settlement under a downspout has to be fixed

Good Rough Grade drains water away from the wall

Good Final Grade drains water away without affecting the neighbouring properties

Backfill is required to fill in the area under the steps

Improper grading around this window well may result in basement flooding

This window well is properly graded with backfill all around