We just came out of what seemed like a never ending rainy season that kicked off after a never ending winter, which led to a lot of leaky basements and homeowners asking how to make a basement waterproof. Firstly any basement waterproofing contractor promising to make your basement completely waterproof should be questioned and some homework should be done to investigate any BBB complaints. Bottom line is that your basement is in a hole in the ground and no one can control mother nature completely. However; short of natural floods that push water into basements through windows etc… you can actually waterproof your basement and stay dry when your neighbors are getting out the shop vacs.
So we should define what waterproof means as it relates to your basement. Waterproofing stops water from getting into your foundation. Your foundation four the sake of this conversation is the basement walls. So to truly have a waterproof basement you would need to apply a waterproof membrane to the exterior of your basement walls to stop water from getting into your foundation. If you have wet basement walls higher than the bottom row or two of block then that means water is entering your foundation above the floor level and the original waterproofing seal is compromised. In this case you have a surface water issue and exterior basement waterproofing will actually waterproof basement walls and dry up your basement.
Now I may confuse the matter a little. If your foundation is dry, that is if your basement walls are dry, but you have water that leaks through the edges of the floor at the wall – floor seam or up through cracks / weak points of the floor… then exterior basement waterproofing may not solve your problem. You may have a ground water problem in this case which may require a different approach to dry up your basement. Ground water problems usually show only after sustained periods of rain or fast heavy downpours. The leaking appears at the wall – floor seams after these sustained conditions occur and may even continue to seep even after the rains stop. This is because the ground water is building up around your foundation from below and has nowhere to go other than in to your basement until the water subsides to below your floor level. In this scenario an interior basement waterproofing system will catch the water from below the floor level and prevent the build up, relieving the hydrostatic pressure that pushes the water in. Ok, so to call it “waterproofing” is not the best definition since it is actually a ground water control system also called a hydrostatic pressure relief system. The term interior basement waterproofing has become the generic label for these systems although technically it does not consist of a waterproof membrane. Nonetheless, you will have a guaranteed dry basement with an interior drainage system if you have a ground water problem.
Not all interior basement waterproofing systems are equal. Some systems are simply an evolution of the old baseboard gutter that the DIYers would glue to the floor to keep water from running through the basement. these systems are channels that are installed level under the floor on top of the footer. Level is the operative word here, level means water lays in there and creepy bugs love water. Look for systems that consist of a true footer drain installed below the floor and is pitched to run downhill to the evacuation point. Furthermore any water that is building up under the floor has to push up into the drain on top of the footer to get to the drain maintaining the water level at a very high point.
There are always exceptions, meaning some basements need a little bit of a combination of methods to solve the problems and ensure a dry solid foundation. Look for basement waterproofing contractors who do not sell a patented system. These businesses train sales people to sell their unique system to everyone they visit which is the one size fits all mentality. It is the only thing they can sell so they are very good at convincing unwitting homeowners that theirs is the latest and best solution. They will even go so far as to say the are full service and can sell you any solution. They will review different methods and point out why it won’t work narrowing you down to the one they sell…it’s like the old slight of hand card trick. Look for contractors who are truly custom and demonstrate problem solving skills that lead to a solution or combination of solutions that fix your unique basement water leaking problems.