Foundation waterproofing is a crucial process designed to protect a building's foundation from water intrusion, preventing issues like leaks, mold growth, and structural damage. For existing homes, this often involves a comprehensive external waterproofing method that addresses water at its source before it can penetrate the foundation walls.
The External Foundation Waterproofing Process for Existing Structures
Waterproofing an existing basement or foundation typically involves several key steps that work together to create a robust barrier against moisture. This method focuses on redirecting water away from the foundation walls.
1. Excavation: Reaching the Foundation's Base
The process begins with excavating the soil around the entire perimeter of the foundation. This excavation is deep, extending all the way down to the bottom sides of the footings. This critical first step provides full access to the foundation walls that need to be treated.
2. Cleaning and Preparation: A Clear Surface
Once the foundation walls are exposed, they are thoroughly power washed to remove any dirt, debris, efflorescence, or old coatings. After cleaning, the walls are allowed to dry completely. A clean, dry surface is essential for the proper adhesion and effectiveness of the waterproofing materials.
3. Membrane Application: Sealing the Walls
With the walls clean and dry, a waterproofing membrane is applied. This membrane acts as an impenetrable barrier, preventing water from seeping through the concrete or block foundation walls. It effectively seals the foundation, creating a watertight layer.
4. Drainage Installation: Redirecting Water Away
Following the application of the waterproofing membrane, new drainage tiles, often referred to as weeping tiles, are strategically placed. These perforated pipes are laid at the side of the footing, typically surrounded by gravel. Their purpose is to collect any water that reaches the foundation level and direct it away from the building, usually to a sump pump system or a storm drain. This crucial step ensures that hydrostatic pressure, which can push water through the foundation, is relieved, and water is efficiently diverted.
By combining an impermeable membrane with an effective drainage system, external foundation waterproofing provides a long-lasting solution to keep basements and crawl spaces dry and healthy.
