The interior perimeter drains or “French drains inside the basement” around the perimeter of the foundation sole are the best line of defense against groundwater if you cannot make an external French drain.
The reason we suggest this method as a secondary solution is that an indoor French drain gives you a dry basement but does not protect the foundation walls from future deterioration.
Membranes outside the foundation prevent wear and tear due to water pressure.
Indoor basement systems
The Inland French drains are installed next to the sole to intercept groundwater before it enters the building and not just a gutter system that collects water after it has flowed into the wall. The BNQ drain against the iron ochre is perfectly compatible with this option.
In our experience, we have seen that water comes from two sources: water that passes through the wall OR groundwater rising from under the concrete slab. Our system covers both of these issues.
Installing a French drain inside
To create a French drainage system inside your home, we first dig the basement floor along the perimeter of the wall, all along the foundation sole.
Then we clean and tilt a trench to the pit of the sump pump we create. A dimpled plastic membrane called Delta-MS is installed to completely seal the foundations and direct incoming water into the trench.
We install a French drain perforated around the perimeter to direct the water into the sump. The trench is filled with 3/4 inch clean gravel to protect the drain and facilitate the flow of water.
Finally, the floor is re-cemented and our staff removes any excess debris.
Deal with a Quebec contractor who specializes in foundations and whose 20 years of experience in concrete work provides you with sustainable structures and repairs.
Steps to install a French indoor drain
- Cut the floor about 12″ deep and 12″ wide around the perimeter.
- Clean the trench with an appropriate slope to the sump pump pit.
- Create a sump pump pit.
- Apply the wall drain and protective panel (DELTA MS).
- Lay the French drain (weeping slab) wrapped in a geotextile protective fabric.
- Connect the French drain to the existing drain or create a sump.
- Cover the drain with 3/4″ gravel.
- Reciment the floor.
- Remove any excess soil and clean the work area.
Free submission within a 30 km radius. Beyond this radius, the $120 fee for the bid is refunded if the client signs the contract for the completion of the work with us.