CRITICAL CRAWLSPACE INFORMATION
Find out the true facts that many crawlspace improvement companies don’t want you to know!
(1) Fiberglass insulation should never be installed in a crawlspace.
“I’ve taken hundreds of samples of crawlspace fiberglass insulation and 100% of the insulation is severely contaminated. – Jeff May Environmental Indoor Air Quality (IAQ) Expert
Fiberglass insulation in crawlspaces is unsafe and unhealthy. It should be removed! Fiberglass insulation holds moisture next to the wood. Bugs, rodents, and snakes are often found in fiberglass insulation.
This professional moisture meter measures wetness in wood from 0-30% - this damp crawlspace with fiberglass insulation tops out at 30% as seen in this video.
(2.a) Spray Foam Insulation is A Bad Idea in Crawlspaces
Spray Foam insulation has been installed by insulation contractors over the past 10 years in crawlspaces. However these contractors have very little experience in Indoor Air Quality and most fail to explain the potential for toxic chemical output and odors from foam. Recently a home in Jackson, Ga had chemical odors from crawlspace spray foam that had permeated the house. As seen in this video, the spray foam had to be removed with our Dry Ice Blasting equipment at additional great expense to the homeowner. The foam had been sprayed on the crawlspace walls and into the perimeter joists.
(2.b) Never put spray foam in the subfloor of a crawlspace.
Spray foam does not clean or seal the wood. If the foam outgasses it would be almost impossible to remove all of it from the wood subfloor. Outgassing does include toxic chemicals. There is actually very little insulation value to spray foam in a crawlspace; however, spray foam is very effective in attics.
Furthermore, if termites infested the wood you would never be able to see the damage until it was too late. There are clean, safe forms of insulation the can be installed on the crawlspace walls. Never put any form of insulation in the subfloor of a crawlspace.
This is our former spray foam rig that we used in attics and new construction, but never in crawlspaces under the house.
(3) Dehumidifier Substitutes for Crawlspaces and Basements
Some local radio ads have been promoting small ducted air mover machines as dehumidifier substitutes.
Amazingly, these machines suck conditioned air out of the house, then pulls it through the crawlspace, and then blows the conditioned air outside, raising the power bill and not dehumidifying. They have been proven to be ineffective, even causing additional air quality problems. Here is a picture of an air mover duct in a basement and it is the same air mover that also goes in a crawlspace.
The following picture shows a proper commercial dehumidifier, keeping the space dry.
(4) Pest Control Dry Crawlspace method fails to dry crawlspace
Greg Weatherman says, “Soil is always wet, even when it appears to be dry….You should never have bare soil below a structure where you intend to live or work! The following pictures illustrate attempts by many pest control companies to dry crawlspaces that simply do not work.
Vent fan installed on wall actually brings in outside humid air instead of drying the crawlspace
Fiberglass insulation in crawlspace is severely damp
After the customer spent $5000 to dry the crawlspace, the moisture meter still indicates the wood is very wet and the fiberglass insulation was not even removed.
(5) Healthy Dry Crawlspaces
A professional dry crawlspace means that all the fiberglass insulation is removed and the area dried. All of the wood is cleaned and treated with a permanent wood sealer. The gound needs to be covered with a permanent crawlspace liner and the vents closed. Finally, a commercial dehumidifier or hydroxyl generator is installed. Always keep the space dry for healthy air.
For over 30 years we have worked in many aspects of the indoor air quality business.