The word “waterproofing” can cause some misconceptions about how this work is done. “Waterproofing”—the way we may think about it—is not possible, but there are many ways of managing water effectively.
So Why is Water Coming in My Basement?
Hydrostatic pressure is the force of water standing behind something. When the water builds up in clay soil (for example), it puts pressure on weak points in the foundation such as the mortar joints between the stones or blocks (called a cold seam) and begins to weaken them. Similarly it can have the same effect on cracks in concrete walls to the point of penetrating through the foundation.
French drains are used to release the hydrostatic pressure and prevent water from pushing against the surfaces by directing it to a more preferable area. French drains help prevent moisture from penetrating through the wall and causing more issues like cracking or buckling. There are many versions of French drains and some are better than others.
Cinderblocks are made of sand, gravel, water, and lime. Lime is the bonding agent for the sand gravel and water (the glue). Water is a natural solvent. Rainwater and ground water are naturally acidic. When acidic water is introduced to concrete or cinder blocks, it breaks them down back to their natural state of matter. When you see the white powdery stuff, it simply means that the water is washing the glue out of the cinder blocks through a process called efflorescence. Ultimately, efflorescence is the decomposition or the chemical breakdown of material. Generally, people can tell if the walls are holding water. How do you know for sure? Looking at the wall and bottom two or three rows look wet or damp or see water beading through the wall, generally, means the hollow core cavities are filled with water. If this is the case, there are multiple issues looming.
1. Mold likes dark and damp areas. So this could lead to a mold problem and mold grows on anything organic.
2. Water is a natural solvent and will weaken the structural integrity of cinder blocks or mortar joints by breaking it down through the process of efflorescence.
*Any professional waterproofing will take care of water under the floor as well as water in the walls if you have a block foundation. If it’s not taking care of both problems, it’s not a good system and you’ll have further issues down the road.