Basement Exterior Waterproofing Services in Knoxville

We excavate down to the footer in the affected area and clean the foundation wall and footer so the surface is ready. Then we apply an asphalt material called Blackjack, rolled or brushed on generously to seal the pores in the block. Over that goes a second asphalt based material called Bituthene, which comes in rolls and adheres to the Blackjack. Then we install a protective flex board called Hydroduct over the Bituthene to shield it from gravel and dirt, and back fill with gravel and dirt, finishing with a positive slope away from the house.

Each layer does a different job. The Blackjack seals the pores in the block itself. The Bituthene is a membrane that bonds over the top of it and forms the actual barrier. The Hydroduct protects that membrane from being torn or worn through by the gravel and dirt when we back fill. A single coating on its own would not survive the back fill.

It is not better in every case, it is different. Exterior work stops water before it reaches the wall, which is the more thorough approach when the conditions allow it. It also requires excavation, so access matters and it costs more to do. Interior work is less disruptive and manages water once it arrives. We recommend based on how the water is getting in, not on which job is larger.

Because it decides where the next rain goes. All the sealing in the world does less good if the ground still tilts toward your house and holds water against the wall. Creating a positive slope away from the house is what promotes proper drainage and keeps the pressure off the foundation you just sealed.