There are chemicals that can be sprayed or painted. There are materials to completely seal your foundation from water. You can also find many professionals that specialize in foundation waterproofing methods. Sometimes you will find recommendations of anchoring walls.
Before you go out and spend money on foundation waterproofing methods, it is even more important to identify and prevent the problem from occurring. The two primary causes of wet foundations and basements are condensation and leakage.
If you determine your problem is from condensation, the easiest solution is to purchase a system that removes moisture from the air.
Foundation Waterproofing Methods
Foundation waterproofing methods for leaking or water seeping in can be a bit more complex. During a heavy rain check to see how the water flows around your home. If you find water draining towards or near your foundation, you will need to redirect it away from your foundation. Water that is standing on the surface at or near your foundation will seep down through the soil and may be seeping into your walls.
If you determine problems, you may need to have the area re-graded to direct the water flow away from your home. Also, the problem may be from gutters that drain improperly or in the wrong direction. In all cases, you need to direct the water away from your home as much as possible.
Eliminating or improving the source of the water will help to improve the problem and may prevent you from needing more involved foundation waterproofing methods. After you've corrected the source, you will most likely still want to apply either a spray on or painted sealer. Remember, water will seep from the soil into your foundation. While doing everything you can to assure water flows away from your home, the soil at your foundation will still hold water.