Need Advice on Insulating Under the Trailer

[tlukasavige172]

I have a 41' 5th wheel trailer made by ATC. I'm looking to insulate under the floor and I'm wondering what material the major RV manufactures are using to cover the bottom of the trailers (it looks like a black corrugated cardboard type thing)? Or maybe you have a better solution or product? Thanks

Moderator edit to re-size picture to forum limit of 640px maximum width.

[tlukasavige172]

Thanks for the info. I already have sheets of 3'' foam insulation which I was going to use as it was left over from another project and then I was going to put the Coroplast over that. Does anyone see a problem in that?

[mguay]

GregK wrote:

mguay wrote:
Here is a link to a post with pics on what I did.

We can't view the pics unless we register there. 😞

Sorry! Try this

[EsoxLucius]

Low-E Automotive Insulation

http://www.lobucrod.com/

[GregK]

mguay wrote:
Here is a link to a post with pics on what I did.

We can't view the pics unless we register there. 😞

[mguay]

I Spray Foamed mine! You can get a DIY kit at those same box stores as OB recommended. There is about 600bdft in the kit which should yield you about 2" on the length of your rig. Or look up a local insulation contractor. Just make sure to wrap the tank valves and sensors in fiberglass batts before application. Once SF is applied it is almost impossible to remove. The FG makes it easier to break loose in case a repair is needed.
Here is a link to a post with pics on what I did.
Mine came from the factory with Coraplast and I would recommend that you still install it even if you foam it.

[Old-Biscuit]

Coroplast Sheets......most any big box hardware store or sign shop 4'X8' sheets
And lots of self-tapping screws and several tubes of caulking to seal edges/seams

Refectix Insualtion.....bubble wrap with an aluminum foil type backing
Also most any big box hardware store........rolls

Foam pipe insulation for any exposed plumbing running under trailer (before installing the underbelly)

[WoodGlue]

The hard one is called CoroPlast and some Home Depots sell it. There is also the woven fiber type:

Woven Underbelly Material

If I were you, I'd also draw a diagram of the underbelly for future reference.

WoodGlue