Misconception: Don’t Remove Insulation During Mold Remediation

Not removing the sub-floor insulation during mold treatment comes up on just about every crawl space inspection. The concept of doing less to save money has always been around, but we feel there are some areas of crawl space repair you should make sure are completed properly.

Not doing mold remediation properly just to save money today will cost you in the future. Improper mold remediation could have an effect on your home and your health.

Sub-floor Insulation Traps Moisture

Part of the reason the sub-floor of your crawl space is growing mold is because of high humidity and perhaps a water leak from above. But, sub-floor insulation is also great at absorbing and trapping moisture. The reason I mention this is even if the water leak is fixed and the humidity is lowered, wet insulation can continue to stay wet.

What is Kraft Paper

Most sub-floor insulation has a paper backing. This type of insulation is called kraft batt insulation. The paper is said to be a waterproof barrier, but the waterproof barrier is not that effective at waterproofing. Floods from toilets can get trapped between the sub-floor and the waterproof barrier. Humidity can travel via the joist, bypass the waterproof barrier, and transfer to the sub-floor. However, once the moisture is trapped between the kraft paper and the sub-floor it becomes a great waterproof barrier.

Types of Crawl Space Insulation

The insulation material can also trap and hold moisture. These materials could be rockwool, fiberglass, or cellulose. I have even seen sub-floor insulation made of recycled blue jeans. The material usually dries once the humidity is lowered, but, according to the manufacturers, it becomes compromised. Compromised insulation loses its R-value and should be replaced. Another way insulation is compromised is by critters nesting in it. The amount of urine and feces deposited on the insulation creates odors and lowers R-value.