Water inside your basement or eroding the foundation walls of your home can be a significant concern. Exterior waterproofing is an excellent way to combat the effects of water in the house and protect the concrete foundation walls, but on older homes, it can be a lot of work. Leaks and Cracks Cracks in the foundation walls of your house can let water run into the basement, but many times the cracks are a result of water infiltration from the soil around the foundation.