Under Belly Insulation?

57chevyconvt

Well-known member
I have removed the front section of coroplast to repair water damage from a leaking 1/4" ploy tubing to the refer icemaker. Since the coroplast and aluminized bubble rap is down, could or should I add some fiber glass insulation to the underbelly for added thermo value? The weight of 3 or 4 inches of additional insulation should not be a factor. I do not want to add something that would be of detriment rather than benefit. What are your thoughts?
BTW - I had to replace the 4" duct work and insulation to the kitchen floor vent because the fiberglass insulation was saturated with H2O and no way to dry it out. I rang out about 2 qts. of water that had accumulated in the insulation around the plastic duct from the water leak at the rear of the furnace.
 

TandT

Founding Utah Chapter Leaders-Retired
I like to insulate whenever and wherever possible. The idea sounds good. However, it would seem like there should be a better product for your purpose than fiberglass roll insulation.
All I can picture is the mess you would have, if there was ever a leak of any kind. I wonder if there are any water resistant products other than spray foam, that could be removed if necessary? Trace
 

hoefler

Well-known member
High density styrene foam board. I used 1" thick under my fresh water tank when I remounted it after it started to fall out. The 1" has an R value of 7.5 where as the foiled bubble wrap has no real R value and the fiberglass was smashed paper thin, soaked with water from condensation, and no R value either. it is rigid, can be worked with simple wood working tools, light weight, and can be held in place with screws and fender washers. I am thinking of replacing the rest of the coroplast with it. I have been over 6,000 miles since the repair and no evidence I will have any problems with it.
 

Birchwood

Well-known member
Because of leaking sewage I replaced the insulation twice in this area.I tore away
the 2 inck yellow batts and replaced it with 4 inch pink batts.If there is a leak in
this area this is where the water will collect so no need to get fancy.
 

Bob&Patty

Founders of SoCal Chapter
Jim, use the 2" foam board. It has an "R" value of "11" I think. Some construction adhesive and drywall screws with washers will hold it place. I installed it everywhere that I could find the sub-floor plywood. In most places I doubled it up. Throw away the "bat" insulation. BTW, I doubt that the floor under the BR is insulated. If yours has the Black covering, remove it, use the 2" and 1" foam board, glue them together, cut to fit and install it. I put the "shiney" side on the 1" up. Made a world of difference in the BR floor tempurature. I also modified the underbelly heating system (long story). But, we now have "radiant floor" heating with the heater on.
 

57chevyconvt

Well-known member
As always, thanks for the valuable input. I am on my way to Lowes to buy some foam board! Prior to now, I had never given consideration for the foam board insulation and the fact it will not asorb water, which is a plus.
 

Sandpirate69

Well-known member
I'm getting ready to take the underbelly off. First question: Is that coroplast sealed against the frame? If it is, what do I use to seal it again? 2nd quest.: the foam board, did you place it against the bottom of the floor? I can use all the technical information possible. I may also install some tank heaters as well.

Thanks,
Ivan
 

jbeletti

Well-known member
I removed about 10 screws/washers in a row on my Landmark last week. The coruplast was not sealed to the frame. Doubt yours will be either. That will make it easy for entry. If you want, you could seal it up after you're done in there, though it may make re-entry a bit difficult.

Jim
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Search for underbelly, there have been some threads on it. I strongly recommend getting an automotive creeper to lie on while working under the trailer. It will save *EVERY* muscle in your body from aching!

A heavy-duty cordless drill or impact wrench will help as well to remove the screws. Getting it down isn't too bad, putting it back is much harder!
 
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