# Ontario Foundation Grading and Drainage: The Source-First Approach to Wet Basements

**URL:** <https://home.renovation.reviews/t/ontario-foundation-grading-and-drainage-the-source-first-approach-to-wet-basements/46903>\
**Category:** Ontario\
**Created:** [April 26, 2026, 7:02pm UTC](https://home.renovation.reviews/t/ontario-foundation-grading-and-drainage-the-source-first-approach-to-wet-basements/46903 "2026-04-26T19:02:36Z")\
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**Author:** ![system](https://home.renovation.reviews/user_avatar/home.renovation.reviews/system/32/77_2.png) [@system](https://home.renovation.reviews/u/system)\
**Post date:** [April 26, 2026, 7:02pm UTC](https://home.renovation.reviews/t/ontario-foundation-grading-and-drainage-the-source-first-approach-to-wet-basements/46903/1 "2026-04-26T19:02:36Z")

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Grading and drainage are the first line of defence against basement moisture in Ontario homes. Addressing water at the source is almost always less expensive than waterproofing after the fact.

**Proper Grading Standard**  
Grade must slope away from foundation: minimum 1 inch per foot for the first 6 feet. Settlement adjacent to foundations is common after 10-20 years and creates persistent moisture problems. Re-grade with compactable clean fill in compacted lifts — never straight topsoil (retains water). Final topsoil layer 4-6 inches.

**Window Wells**  
Windows at or below grade require window wells. Wells must drain: connection to weeping tile or 8+ inches of clear gravel at base. Covers reduce leaf and debris accumulation.

**Downspout Extensions**  
Extend minimum 6 feet from foundation. Underground extensions to daylight or dry well are preferred. Never connect downspouts to foundation weeping tile — roof runoff volume overwhelms systems designed for ground seepage.

**Surface Ponding**  
No water should pond within 10 feet of foundation. French drains or surface swales address flat-lot drainage problems.

**Costs Ontario 2026**  
Re-grade and re-sod around foundation: $1,500-$5,000. Underground downspout extension: $200-$800/downspout. French drain installation: $3,000-$10,000.

Discuss grading and drainage at home.renovation.reviews.