I get it, no one wants to go crawling around under their house! Especially if you only have about 18 inches to work with. Someone should however, go under your house at least once a year to ensure that your crawl space is in good order. Too many crawl spaces are neglected and home owners are often then forced to be reactive instead of proactive.
So here we are, being reactive. Mold has started to grow on your floor joists and maybe also your sub floor. Let's first talk about how to handle your mold problem. Then we can go over why mold is growing under your house. Finally we will finish up with how to be proactive!
You can call most pest control companies and they have a ''mold killing'' process. This usually consists of spraying the mold with some kind of mold killing compound followed up by a mold prevention compound. Oftentimes though, they leave the compromised insulation in place and spray around it. There are many issues with this process, one being that you are only killing surface mold by spraying it with a compound and there is no guarantee you will kill the mold that has rooted deep into the wood. If you don't at least move the insulation, you won't get all the mold on the floor joist or any that has grown on the sub floor. Lastly, fiberglass insulation has been proven to hold moisture and mold can even grow on the back of the insulation. So without at least pulling down the insulation to inspect it when you are spraying for mold, you are risking doing all for nothing.
Now that you know what not to do, let's talk about the right way to tackle your mold problem through mold remediation. Starting first with removing all the insulation in the troubled areas and inspecting behind the rest of the insulated areas. Or more preferably, removing all fiberglass insulation and instead insulating the foundation walls when you're done. Now that you have assessed the situation, next comes the mold clean up phase by means of a soda blaster, an air powered pressure blaster using a baking soda media. Same concept as a sand blaster but with baking soda instead. This removes the mold from the wood all the way to the base of the mold and gets you back to square one. I also hook up an exhaust fan to one of the vents to help get the mold and dust to exit the crawl space when blasting. Once you are back to a nice clean wood finish again, I like to spray Concrobium on the floor joists and sub floor. This is a mold killer and more importantly, a mold preventative.
There can be a lot of reasons why you have mold in your crawl space including: poor gutter drainage, the property is sloping towards the house instead of away, a high water table, no vapor barrier, or leaving your vents open in a humid environment.
It is crucial to take all these factors into consideration to prevent mold from regrowing under your home. A vapor barrier is an absolute must for crawl spaces in humid climates. But it is also imperative to take all other factors into consideration in order to keep moisture out of your crawl space so that you do not allow the mold to return.
For a short video on how to remove mold from the floor joists and sub floor, click this link!
-Written by Lee Sell