A sloped surface is required to effectively drain water away from all foundation walls and concrete slab-on-grade buildings, including areas underneath steps and decks.
Minimum Grade Requirements
- 10% for first 2 metres with a minimum of 20 cm drop for final grade on soft landscaping
- 5% for the first 2 metres (slab-on-grade) with a minimum 10 cm drop for final grade on soft landscaping
- 0.75% for concrete, asphalt, or other impervious surface treatment
The Lot Grading Drawings page illustrates the minimum grade information for different lot types in PDF formats.