Exterior waterproofing (or sometimes known as external waterproofing) repairs your leaky basement from the outside of your home by exposing the foundation and applying the necessary waterproofing material to create a foundation waterproofing system that will redirect and disperse water away from your foundation walls. This is one of the best waterproofing solutions used to fix basement leaks and the most common way to do a basement foundation repair.
The waterproofing materials include hydraulic cement, two layers of Hydro Guard rubberized membrane, a reinforcement mesh, air-gap drainage membrane, drainage tile (weeping tile) and 3/4 inch gravel.
The Differences Between Damp-proofing vs. Waterproofing Your Basement
When you hear the terms “damp-proofing” and “waterproofing” in regards to your home’s basement and exterior foundation, is there a difference? What do these terms mean?
There are differences – and these differences are extremely significant!
Exterior damp-proofing is the process through which a liquid asphalt-based product is applied thinly to your foundation. Since there is no rubber, damp proofing does not provide any crack-bridging capabilities. Damp proofing done during the construction phase of a home aims to meet only the minimum building code standards and costs approximately $20-30 dollars to cover 100 feet of any foundation. Homes built prior to 1980 do not have the protection of damp proofing or waterproofing, leading to the deterioration of their foundations. Although damp proofing protects from some dampness, it cannot withstand water penetration.
Exterior waterproofing is a process that waterproofs and seals foundations by bridging cracks or faults caused by movement. RCC’s commercial-grade product, Hydro Guard, is used in our main waterproofing process. It is applied in a two-layer application method and costs $200-250 dollars to cover 20 feet. The usage of a commercial-grade waterproofing product allows RCC to guarantee 50-year protection against dampness and water penetration, unlike damp-proofing.
NOTE: When waterproofing your home, be cautious of the products used to complete the work. Many contractors and waterproofers will promise to do waterproofing, but use damp-proofing products to reduce the cost of their materials.
Exterior Waterproofing Benefits
Reduces the moisture in a basement
This eliminates sources of musty odors and allergens within your home.
Eliminates foundation wall deterioration while improving the structural soundness:
This leads to reduced costs of future home repairs and prevents loss of personal belongings due to a water-leakage.
Increase your property value
When a home experiences moisture and water issues, it may lead to a drop in the value of home. Realtors usually recommend hiring waterproofers to fix basement issues, making waterproofing pivotal to increasing the value of your home.
Strengthens the foundation of your home
Water leaks can weaken the structural base of your foundation, leading to future problems like interior cracks and shifting of your floors.
Water-proofing gives you peace of mind for the structural safety of your home and the security of your belongings.
Common Exterior Leak Problems
Basement Window Wells
Water build up around near-grade basement windows can cause water infiltration through your window sill.
The addition or replacement of malfunctioning window wells accompanied with installation of vertical weeping tile and a bedding of 3/4 gravel will ensure that water entering your window area will be drained. This will prevent leaks in your foundation and flooding of your basement.
Block or Brick Foundation Homes
Block and brick walls contain air voids and mortar joints that could allow water flow to enter the cervices of your walls.
A combination of external and internal waterproofing methods can be used to prevent and repair water infiltration within block and brick foundations. Water pooling found inbetween brick walls are drained by drilling through the interior of the foundation to drain the water buildup.
Joint leaks include the junctions between your wall and footing, your basement floor and foundation and the joints where new extensions have been built.
Hydraulic Cement is used to patch and fill these various types of joints. The modified cement is key to preventing further damage and water leaks.
Top of Foundation
The Sill, or where the foundation meets the brick could become a spot where water leakage happens if the sill is not sealed or if the original seal has deteriorated.
Maintaining the Sill using a waterproof sealer is important for fixing this issue and preventing water penetration into you sill. Even though there is no hydrostatic pressure, water can still find its way through this spot.
Exterior Waterproofing Process
1. Exterior waterproofing requires excavation around the perimeter of the building: Most excavations range from 4 to 8 feet deep and approximately 2 ½ feet wide. The dimensions of the excavation are dependant on the elevation of your property.
2. Installation of Speed Shoring: This is done to ensure the safety of workers while preventing soil re-filling the area of excavation.
3. Old Weeping Tiles are Removed: Excavation is done util the footing is reached and the old weeping tile can be taken out. A new 4-inch weeping tile with a filter cloth is then installed.
4. Cleaning and Inspection of the Foundation Walls: Foundation walls are then cleaned and inspected for any voids or structural cracks. The defective areas are chiseled out and repaired with non-shrink specialized cement which expands when applied to the crevices.
5. Application of Trowel-On Rubber Membrane: This is a central component to exterior waterproofing your foundation. Its designed to elongate and expand in case of further foundation movement and settlement.
6. Installation of mesh on top of membrane and final layer of rubber waterproofing: This is used to reinforce the first layer of the rubber membrane and acts as a secondary rubber layer.
7. Soil side drainage sheet is fastened to the top of termination bar: Commercial grade drainage acts as a protection board and drainage membrane (much better than residential grade dimple board)
8. Installing Window Wells: If your home has any windows below grade and you require a window well installed. A 4-inch weeping tile is installed vertically down from the inside of the window well to the footings. To prevent clogging, makes sure your weeping tile and pipe do not touch.
9. A layer of 3/4 inch clear gravel is placed over the weeping tile: Used to maximize the level of drainage. The layer of gravel is mixed with soil to prevent too much water absorbtion through the weeping tile, which could lead to slowed drainage or clogging.
10. Area is refilled with native soil and compacted to the original level: Once the soil has been restored to its original places, you have fully waterproofed your foundation and will have no further issues with water penetrating your basement exterior or interior.