Insulating

[Camperdude]

For those like me, who just can't accept highly mediocre as an acceptable bar that's been set by these manufacturers, and insist on making them better, how hard was it to improve on the underbelly insulation? I'm thinking an early spring time job for me is going to be removing the corroplast and fortifying the insulation with something better. I have a gray tank valve giving me grief so I think I'll kill two birds with one stone...

Just curious to find out who's done this, how you did it and what your results were as well as what materials you used/recommended.

Thanks everyone!!!

[RoadrunnerII]

We upgraded the underbelly insulation couple years ago.
Added fiberglass batts and a layer of reflectix from I beam to I beam from basement to rear wall. Made a difference on the floor temp and heat and cooling requirements.
Also plugged holes in frame for rear leveler wires and along entire coroplast.
When we pulled it down the 2 batts of fiberglass under fresh water tank where soaked from water splashed up on exterior of I beam and running inside. Not much insulation value in wet fiberglass.
Reflectix is between coroplast and fiberglass. Each seam in coroplast is taped together with aluminum tape. Thinking it will help keep moisture from getting into the batts.
We used black gorilla tape to seal along edge of coroplast all the way around.
Also stuffed front bubble with fiberglass batting. It had areas where there was no insulation.
Added a definite cold heat barrier on fron closet. It also added a bit of noise deadening.
Overall it made a noticeable difference on interior.
We had a peek up thru the corroplast area this year to string 12 volt wire to water pump we put in the island. Dry, no mold so I believe it's a good fix.

YMMV
RoadrunnerII

[TedsCanoe]

Fantastic info, many thanks.
I'm in the process of putting 12v heating pads on fresh and grey water tanks (black will be a porta-potty.) After the pads are glued on I was thinking of rigid foam but that will just get trashed on the gravel and muddy roads I sometimes have fun with.
So would Reflectix taped to the trailers beams then coroplast to protect the bubble/foil or just the Reflectix taped to the trailer beams?
Thoughts appreciated.

[RogerR]

Reflectix is just mylar coated bubble wrap. As such, leaving it uncovered on the bottom and it would pop or tear every time a rock or stick hit it. I use it as a near zero weight insulation on my windows with the dual use as reflecting sunlight that deteriorates and fades the interior. Works on roof vents and bath skylights. Keeps heat in on winter nights, light out if you are parked next to bright lights at night for better sleep.

[TedsCanoe]

fiberglass, bubble/foil and coroplast in that order then.
Does the coroplast already used under some units have any kind of barrier like vinyl cloth to protect it or is it just good old everyday 4mm 5/32" Homedepot coroplast ?

P.S.: What a great site with fantastic help. Really appreciated everyone.