How to Fix a Flooded Crawl Space

I have lived in my house for 27 years and my crawl space flooded for the first time during hurricane Irene. I had 8 inches of water in the crawl space. The floor of the crawl space is sand with a plastic vapor barrier. I removed the water with a portable sump pump and a wet vac. I have been running a box fan at the entrance full speed for 48+ hours. The only thing in my crawl space is the holding tank for the water from my well. The pressure switch got wet and had to be replaced on the tank.

Do I need to remove the old vapor barrier and install a new one because it got wet?
Since it flooded, should I now have a sump pump installed?
Should I spray the crawl space with some kind of anti-mold solution?

Thank you.

Our Answer

27 years is a pretty good track record and tells me that this is no time to panic over a flooded crawl space brought on by a hurricane! It is however, a good time to make sure the basics of flood-proofing a home are covered.

First, most crawl spaces and basement flood due to a drainage problems including (1) gutters that are clogged, disconnected, undersized and or just not draining far enough away from the foundation; and (2) the soil around the foundation perimeter not sloping away from the foundation. It may either be flat, sloping in toward the foundation, or the run-off trapped by landscaping improvements like railroad-styled ties that are used to frame a landscaping bed.

For more details see my article on How to Waterproof a Basement or Crawl Space.

As for your specific questions:

It's not necessary to replace the vapor barrier because it got wet, unless it also is damaged. I assume this is a plastic vapor barrier so if that is the case you don't need to replace it;

You do not need a sump pump installed! As explained above, your focus should be on the causes of the flooding at the foundation perimeter and stopping the water form getting there in the first place.

As for an anti-microbial treatment, if you have seen any signs of mold, this could be advised. An easy solution you can make yourself is to mix one part bleach to 4 parts water, and spray on the affected areas. Learn more here about house mold clean up.