Interior basement waterproofing, without digging up your yard.

How an interior drainage system works

1. 01

   Open the perimeter

   We cut the slab along the walls and dig a channel below floor level.

2. 02

   Set the drain and membrane

   Perforated drain goes in the channel in clean stone, and a dimpled membrane on the wall guides any water down into it.

3. 03

   Carry it away

   The drain runs to a sump that pumps the water outside. The floor is patched and ready to finish.

When interior is the better choice

• Outside access is blocked by an addition, deck, driveway or a neighbour's wall.
• The basement is already finished and you'd rather not dig up the yard.
• Water is coming in at the floor-wall joint along several walls.
• You want the job done in days rather than weeks.

What it does and doesn't do

An interior system manages water rather than keeping it off the wall. Water still reaches the outside of the foundation, but it's captured and pumped out before it reaches your floor. For most basements, that's a dry, usable space. If you want water kept off the wall entirely, or the wall itself needs repair, exterior work is the answer.

Interior systems typically run $80 to $180 per linear foot, or around $10,000 to $20,000 for a full detached house including the sump. In Halton, disconnecting the weeping tile and adding a sump can be covered by the Region's subsidy up to $6,500.