It is mainly dirty. Try to clean first with 50% bleach solution. If it does not work, you can use mold kill paint Kilz premier to paint over to kill the mold and cover the odor. If all fail, replace the wood borad.
It is mainly dirty. Try to clean first with 50% bleach solution. If it does not work, you can use mold kill paint Kilz premier to paint over to kill the mold and cover the odor. If all fail, replace the wood borad.