Foundation wall waterproofing

The crews from Lee Rocca Forming Ltd is here working on the foundation wall again. Today they are doing water proofing of the foundation wall.

First they applied an asphalt spray coating to the outside of the living space of the foundation wall. The part you see that didn’t have the asphalt spray applied is the stair foundation wall. Every inc of wall that’s adjacent to living space has the asphalt spray applied. Asphalt spray is not considered as a water proof solution. It’s only a damp proof solution because the asphalt does make the concrete less porous, but asphalt lose its effectiveness as it emulsifies.

Once the asphalt spray is completed, a plastic drainage membrane or dimpled membrane is then applied around the entire foundation wall. This plastic sheet is impermeable to water and water vapor. The sheet is significantly overlapped to provide coverage. The dimples on the plastic sheet prevent wet soil from contacting the foundation wall and allow any incidental moisture that got behind the membrane to flow downwards to the weeping tile.

Once the dimpled membrane is applied and secured onto the foundation wall, they shoot gravels into trenches to cover all the weeping tiles. They’ve also filled the drainage pipe under the basement windows with gravel.

Here’s all the dimpled membrane applied around the foundation wall.

They have installed the dimpled membrane inside the foundation for the concrete stair as well, even though that part of the foundation will be covered and will not be back filled and therefore should technically not have water issue.

And here’s a close up of the dimpled membrane. You can see the asphalt spray behind the membrane and the dimples on the membrane sheet. This is before they put on all the fasteners.

Here’s another show of the dimpled membrane. You can see the fasteners that’s used to hold the membrane against the foundation wall.

And here’s the time-lapse sequence of the day. They started around 8am and they finished around 11am.