View Full Version : Suspended Floor Insulation

Colin Kaminski
08-02-2006, 04:22 PM
I have a beer ageing celler that is maintained at a constant 40F. It holds about 4000 gallons of beer. It is a concrete floor with a drain. We use a lot of water for cleaning in this room. The crawl space underneath is about 4 feet tall. It was installed about 12 years ago.

Lately we have noticed the floor in the ajoining hallway is starting to deform. After inspecting the underside of the room all of the joists in the room have bowed about 2" down.

The surfaces are wet and covered with a black mold. I need to go back down and check everything for dry rot. It is my opinion that the water is from condensation and not from a failure in the seal under the concrete floor. I can find no evidence of any insulation used in the construction of the floor.

We plan to install a stem wall and replace any rotted wood. We can do this without emptying the room or removing any concrete.

My question is what insulation can we use under this floor? Is a spray on insulation recomended? Any advise would be appreciated as the local contractors have not had any experience with this kind of room.

08-02-2006, 05:47 PM
Try these guy's




US Iceman
08-02-2006, 06:10 PM
The surfaces are wet and covered with a black mold.

I would be very careful if this is what you have. Mold is a serious health issue, not to mention possible effects on food products.

Here is a link to review for additional information.


You may have to find someone who specializes in mold remediation to help you with this problem. Once solved, the lack of floor insulation is the next issue.

The condensation issue is due to the lack of insulation as you surmised. Regardless of the insulation type, you will have to provide sufficient insulation thickness in the crawl space. Some minimum thickness will be required so that the surface temperature of the exposed insulation is higher than the air dewpoint temperature of the moist air in the crawl space.

If the floor in the crawl space is dirt, you may have to lay down a vapor barrier to reduce the quantity of free moisture flowing into the crawl space also.

I also recommend you have a structural engineer review the floor loads to ensure the necessary load bearing capability of the joists. If the joists are sagging two inches, something is seriously overloaded.

In my opinion, the mold is the more serious issue. This is very bad stuff and is hard to completely remove once started.