Install the filter sleeve on the perforated pipe, if it didn’t come pre-installed. Then lay the drain pipe in the bottom of the lined trench. Backfill the remainder with clean drainage gravel.

To install a french drain, you'll need a perforated drain pipe such as this one, which is available in a range of sized (including 25m x 69mm, 25m x 100mm, 50m x 60mm, and 50m x 100mm).

When the garage was built, the concrete below the soil line should have been waterproofed. A perforated drain pipe should have been placed alongside or on top of the footing that supports your ...

Laying the Pipe: Place a perforated drain pipe on top of the gravel, with the perforations facing downward. This allows water to enter the pipe while keeping sediment out.