One method of waterproofing your basement is to install a waterproof coating on the exterior walls so water can't seep through the concrete. A thick coating on the walls keeps out water under pressure so your basement stays dry. This is often preferable to relying on a drain system inside that collects and pumps out water. Here's how an exterior waterproofing coating might be applied.
The Walls Are Cleaned And Fasteners Are Installed
Since the dirt has to be dug away from the walls, the walls might be coated in dirt, roots, or other debris. All this has to be cleaned off so the coating adheres well to the concrete walls. Also, an exterior waterproofing system consists of the coating and the drainage boards that top it.
Fasteners are used to hold the drainage boards in place, so the fasteners are installed before the coating so the coating seals around them and stops leaks from occurring later.
The Coating Is Applied
There are a few types of waterproofing options your contractor might consider for your basement walls. Some are membranes that attach or stick to the walls, while others are coatings that are painted on. The advantage of using a coating that's painted on is that there are no seams since the coating creates a continuous covering much like paint.
However, a waterproof coating is much thicker than paint, and it may have a rubbery texture so that it can expand and contract along with the concrete. The coating is applied to the thickness required by the manufacturer and then allowed to cure before being covered by soil.
Install The Drainage Boards
Since the fasteners are already in place, the drainage boards are easy to put on once the coating is dry. Drainage boards have grooves or dimples that create channels that water runs down so rain can be directed to a drain under the ground or other safe place.
Sometimes the contractor will install a French drain along with a waterproofing coating. The drain provides a place for water to go when it rolls down the exterior wall. The drain is buried under the ground, deeper than the footing of your foundation, and it empties far away from your house.
The drainage boards also protect the coating once the dirt is filled in. The dirt presses against the boards so the coating isn't scratched or damaged.
Fill In The Dirt
The coating might be black when it goes on your house and look unattractive, but when the job is done, the coating and drain are under the soil and out of sight. The soil that was removed to create the trench near your exterior basement walls is filled back in and then you can landscape the area.