A French drain protects your basement from water. Yet it is easy to forget about it until it stops working. After 25 to 40 years, it is often clogged or crushed. Here are seven signs that your French drain may need replacing.
1. Water in the basement after rain
The most obvious sign is water appearing at the base of the walls or on the slab after heavy rain or snowmelt. This means water is no longer draining properly around the foundation.
2. Moisture stains on the walls
Water marks, white efflorescence or blistering paint indicate that moisture is passing through the concrete.
3. A musty smell
A persistent musty smell in the basement often reveals excess moisture. It can also affect air quality throughout the house.
4. Iron ochre in the sump pit
Orange sludge in the sump pit? It is probably iron ochre, a bacterial deposit that clogs drains. In some cases, cleaning is enough. However, a heavily contaminated drain needs replacing.
5. Cracks in the foundation
Water pressure against the foundation can create or widen cracks. A crack that lets water in must be repaired, and the underlying cause, often the drain, must be addressed.
6. A home more than 30 years old
Clay or fibre drains installed before the 1990s are more fragile. The age of the house is therefore a useful factor to consider when buying a property or before finishing a basement.
7. A sump pump that never stops
A pump that runs constantly, or never runs at all, may indicate a drainage problem around the house.
How can the diagnosis be confirmed?
A camera inspection is the best way to determine whether your French drain needs replacing. It shows whether the drain is clogged, crushed or contaminated. We then choose the right solution: cleaning, repair or replacement from the exterior or interior.
- Exterior replacement: excavation, a new drain, membrane and free-draining backfill
- Interior drain: installed beneath the slab with a sump pit when exterior access is difficult
- Cleaning: for a drain that is still in good condition but obstructed
To learn more, see our page on French drains and our advice on foundation repair. You can also read the recommendations from theAPCHQ on home maintenance.
