If you notice standing water under the deck after rainstorms, you may need a drainage system to efficiently move this water. You do not want standing water to rest against your foundation or against support posts for the deck, as this could cause significant structural problems over time. Make sure the area has proper grading, too.

If you don’t wish to dig it out and convert it into a finished basement, you can still encapsulate your crawl space to protect it from damage for an average cost of $5,500. Finishing a crawl space beyond this isn’t really worthwhile, as the low ceilings mean you won’t be able to use the area as living space.

Proper basement ventilation is very effective at reducing humidity. Without enough ventilation, your basement is prone to mold and moisture damage. Your basement should have as much natural ventilation via windows and doors as possible, and if your budget allows, you should also consider installing an ERV system to keep basement humidity levels at bay.

Topical sealers adhere to the surface of concrete to create a protective layer. In many cases, this is all you need for concrete that sees light to moderate traffic, such as your basement. Penetrating sealers, on the other hand, bond with the free lime in the top layer of concrete to form calcium silicate, which prevents liquid from passing through. This type of sealer protects the surface from water, oil, and gasoline spills.