Mold and mildew can be easily removed with appropriate cleaners. Some cleaners just clean the mold stains off the wood but don’t prevent future growth, so make sure you know which kind is being used. (Always follow product labels and directions.)
Get a professional plumber to correct any plumbing leaks before an enclosed crawl space is installed. But in addition to fixing leaks, make sure that condensation drains and pressure relief valves are plumbed to the exterior or to an appropriate drain within the crawl space. Your plumber can handle this, too.
Correct the problem from the exterior if you can. Often you have to redirect the flow of water by installing gutters, improving grade around the house so the grade slopes away from the house, installing a foundation drainage system or installing an interior drain system. (Always check your state and local building codes and contact your local pest management, [...]
If you have a water problem that’s coming from the outside of your crawl space, the problem needs to be fixed before you can have a closed crawl space installed.
Closing your crawl space has many benefits, such as reducing the humidity in your crawl space. That prevents mold growth and also reduces insect activity, as bugs like higher moisture levels. An enclosed crawl space also improves indoor air quality and saves energy.