What type of basement waterproofing repair system you choose to install is dependent on your home’s unique situation and construction, including what type of foundation system is in place. It’s also important to note that in many cases, not just one type of repair, but rather a combination of approaches, may be necessary.
Waterproofing primer or paint products
One waterproofing repair that most contractors did not recommend was waterproofing paints or primer. They said that sealing basement walls that have leaked produces little more than a cosmetic solution if the source of the water problem isn't addressed.
This repair approach is generally only suitable for poured concrete foundations where seepage is originating from the walls (and not floors). Masonry foundations, such as brick, stone or cinder block are not ideal candidates.
Injecting an epoxy or polyurethane material into a crack can help prevent water from entering the basement, but some basement waterproofing companies regard this solution as a temporary fix and not a permanent solution.
*Typical cost of crack injections: $300 to $500 depending on the size and length of the crack.
Exterior excavation waterproofing
Exterior waterproofing involves excavating 6 to 8 feet down to the foundation wall footer and correcting drainage by installing new drainage tiles or a French drain system. At the same time, waterproofing companies will also typically apply a waterproof material or membrane to the exterior wall’s surface to make sure that water doesn’t infiltrate it again.
Depending on the number of areas affected by water infiltration, exterior basement waterproofing - also known as positive side waterproofing since it deals with the source of water or hydrostatic pressure - may involve one wall of the foundation, or multiple walls – which would increase the project’s overall cost.
Due to the extensive excavation required, exterior basement waterproofing is often more expensive than other methods. However, it carries the advantage of excluding water from the home and requires little to no ongoing maintenance once the project is complete.
“You’re stopping the water from penetrating the wall and entering the basement,” Chubb says, adding that 95 percent of his company’s work is exterior excavation waterproofing.
The downside, other than cost, is the disruption to the home’s landscaping and attached features such as porches and driveways. Be sure to ask about what your property will look like after the work is complete.
An exterior basement waterproofing company that takes a comprehensive approach should have a plan in place to minimize the impact to your home's appearance. Exterior excavation may also be a poor option for homes that are situated in a high water table area, Chubb says.
*Typical project cost for exterior basement waterproofing: $80 - $100 per linear foot
Interior excavation waterproofing
Contractors say homeowners often choose an interior waterproofing method because it costs significantly less than exterior waterproofing. “It’s the most common and least invasive system,” Phillips says.
Interior drain system waterproofing will address hydrostatic pressure – that is, the pressure of groundwater forcing its way through the basement walls or foundations. Because interior perimeter drain systems deal with water after it has entered a basement, it may be referred to as negative side waterproofing.
Some contractors also prefer the terms “water control” or “water management” since these systems primarily deal with water in the basement after the fact, rather than preventing it from entering the home.
“It’s jackhammering the concrete floor to install new drainage and a sump pump system,” Sackenheim says.
Systems vary, but typically a contractor will excavate a trench 4 to 18 inches wide within the perimeter of the basement. Drainage tiles or piping is then installed, routing water from seepage areas to a sump pump system. To remain effective, the pipes or drainage tiles must remain free of obstructions or clogs; some contractors will install access ports for maintenance.
Another key part of the system is a working sump pump to actively remove water once it has entered the home. With this type of system, waterproofing contractors also suggest that a backup battery-operated sump pump is an essential consideration to prevent water from overtaking the basement during power outages.
While interior excavation and drainage systems are less costly than exterior systems, they’re not without their drawbacks. Excavating in a finished basement obviously presents issues for a homeowner and some contractors advise that there’s a possibility of structural damage when compromising the integrity of a concrete basement floor.
*Typical project cost of interior excavation waterproofing: $50 - $75 per linear foot
Editor's note: This is an updated version of an article originally posted on May 4, 2012
Have you experienced seepage in your basement? Tell us about your basement waterproofing efforts in the comments section below.