Should I Remove Insulation from Crawl Space
Should I Remove Insulation from my Crawl Space?
This is a question we get a lot. This is because many contractors are telling homeowners that crawl space insulation
is not needed.
Is that true?
Is crawl space insulation needed, or is it better to remove it?
Bad Insulation Choices Should be Replaced with Insulation Designed for Crawl Spaces
I understand why some say it is not needed because certain types of insulation may cause more harm than good. Fiberglass insulation between the joists can house rodents. It can also enhance moisture problems that lead to mold and wood rot fungus.
I have even seen fiberglass insulation blown on crawl space walls. We have also removed cellulose insulation that was held up by netting between the joists. But what I feel is even worse is spray foam insulation applied to wet moldy wood. To me, since many contractors don’t understand how to properly insulate the crawl space, their default response is just to get rid of it.
Insulating Floor Over Dirt Crawl Space
Homebuilders have been insulating the joists of the crawl space for many years.
This old school way of insulation is still practiced today. In some cases this type of insulation is fine but humidity and water can wreak havoc. When fiberglass, rock wool, or spray foam attached to the sub-floor becomes wet, it often creates a mold or wood rot fungus problem.
Trapping moisture can happen during a plumbing leak or from a humid day.
Wet wood is not good.
Covering the sub-floor does not allow the wood to dry properly. Dirt floor crawl spaces or basements are notoriously damp. Installing a dehumidifier is recommended to control humidity. Sump pumps are used to address flooding and standing water. Neither will be effective at drying wood covered by insulation.

Insulating Crawl Space Walls
So back to the question of “Should I Remove Insulation from Crawl Space?“
The answer is yes, if it is trapping moisture – but then replace it with proper crawl space insulation. The professionals at Crawl Space Ninja can insulate the sub-floor of the crawl space if the homeowner likes, but what we try to do is insulate the walls of the crawl space.


