If you’re experiencing a damp, flooded, or smelly basement, chances are you’re wondering about the best way to both dry out your space as well as how to eliminate future moisture build up from occurring. Moisture can enter the basement from various inlets; therefore, the best basement waterproofing method will depend on the source of your water invasion.
Basement Waterproofing Methods
There are 3 methods of basement waterproofing: interior, exterior, and drainage.
Interior waterproofing takes place inside the home and typically includes adding coatings and sealants to prevent moisture, while exterior waterproofing takes place outside the home and can include coating the outside walls with a waterproof barrier, and more. Drainage waterproofing can occur either outside or inside the home, including installing exterior drainage systems, installing interior drain tile, and repairing a poorly working drainage system.
Some of the best waterproofing methods include:
Expanding Urethane Injection
One of the most common forms of basement water seepage occurs from a crack in a poured concrete foundation wall, which can extend all the way from the outside wall to the interior, enabling water to leak into the basement.
Cracks in the foundation can be properly sealed from the inside using an expanding urethane injection, which will fill the crack all the way to the soil outside your home and prevent additional seepage. In addition, the urethane material remains pliable and moves with the wall to prevent additional cracking.
Silicate-Based Concrete Sealers
Silicate-based concrete sealers are applied to brick or concrete surfaces using a roller, brush, or sprayer. Once the concrete or brick surface is thoroughly saturated with the sealer, it chemically reacts with ingredients in the brick or concrete to form a sturdy, waterproof surface.
Silicate-based concrete sealers are what’s known as penetrating sealers; therefore, they won’t peel or flake off, and in most cases, you can even paint over them.
Waterproof paint is an acrylic formula that helps seal walls from water leakage. It is not much different than traditional paint, except it is brushed, sprayed, or rolled onto the surface much heavier.
Waterproof paint can be applied over painted surfaces, and once cured, can even be painted over.
Concrete Waterproof Coatings
Concrete waterproof coating is a thick, cement-like coating that once set, remains permanently on masonry and concrete walls. The coating is typically applied using a sturdy natural fiber brush, such as tampico, and can be swirled during the last application to give the wall, a charming, finished look.
Concrete waterproof coating comes in a dry mix that you simply add water to and can be applied over existing paint.
Interior Drain Tile
Drain tile, also known as “French drain” is a plastic pipe with small holes punched into it that enables water to enter it. Furthermore, it is enclosed with a filtration material to keep dirt and soil out once it is buried.
The pipe itself is buried below a bed of washed gravel, which enables ground water to seep through the pipe where it is then carried away from the foundation by gravity or with the aid of a sump, to another part of the property or into a storm drain.
Installing drain tile does require excavation; however, it is a beneficial way to drain away water that would enter in through the cove joint as well as relieve hydro-static pressure beneath the floor of the basement, which eliminates water seepage through cracks in the area.
To install drain tile, the basement waterproofing crew will smash through the thin basement floor and dig a trench, about a foot deep, around the perimeter of the foundation. The drain tile will then be installed next to the footings where it will provide the best results.
Exterior Waterproofing Membrane
Foundation wall leaks can occur for various reasons. For example, a poured concrete foundation can have small holes or spaces in it due to construction, which can result from improperly mixed concrete, enabling the dry cement to form a pocket, or by inadequate vibration of the poured wall to release trapped air. These permeable spots can, in time, enable water to leak into the basement.
Exterior waterproofing membrane creates a watertight barrier on the outside of the foundation to prevent water from entering the basement via cracks in concrete, brick, or mortar joints, as well as water seepage over the edge of a wall, such as from a sloping lawn.
Once excavation is complete, the wall will be prepped, then a thick coat of asphalt-modified polyurethane will be applied. Once the membrane has set, it forms a smooth barrier around the foundation that prevents water from entering and helps preserve the structural integrity of the wall.
How Much Does Basement Waterproofing Cost?
Basement waterproofing costs vary depending on the method used and whether you choose to hire a professional or do it yourself. However, some of the most basic costs associated with basement waterproofing are as follows:
- Expanding urethane injection, one of the most common forms of injections due to its versatility, on average costs anywhere from $350-$525 per crack; however, many basement waterproofing professionals offer a reduced rate on multiple cracks, which are not uncommon in foundation walls due to the pressure they endure.
- Silicate-based concrete sealers are available in 1-gallon cans, which typically range between $40-$50 and covers up to 200 square feet. However, keep in mind that you may require at least 2 coats. Waterproof paint is also available in 1-gallon cans, which generally costs around $35 per gallon; however, it only covers up to 75 square feet.
- Concrete waterproof coating typically costs between $30-$40 for a 5-gallon bucket of dry mix that you mix with water and covers up to 100 square feet.
- Interior drain tile, one of the surest ways to waterproof your basement, on average costs between $8,000 – $15,000 for a typical full-perimeter drain installation, depending on the sump pump, accessories, and other additions selected. Installing exterior waterproof membrane, another sure, but costly, way to waterproof your basement typically ranges between $15,000-$30,000. However, it is not uncommon for interior drain tile installation to be combined with exterior waterproof membrane installation for maximum results.
While each of these basement waterproofing methods may certainly be effective on their own, if time and expenses permit, you may consider a combination of these methods for best results. And remember, none of these products will work without properly sealing gaps and cracks, so be sure to consult a professional before application.