Different ways to Insulate the Floor?

[Karebru]

I'm not even sure I'm going to insulate my floor. Heat is my concern, not cold. And we won't be spending much time in the trailer before the sun goes down... We're going to try it without, for now.

But if a guy was going to insulate a cargo trailer floor, how are others doing it?
Between the plywood and the finished flooring isn't an option at this point.
Expanding spray foam seems like it would work well. I've seen attics done that way.
...Might be costly. Are there DIY kits available?
Glued, screwed, and/or taped foam board?
It would have to be attached well enough so that it wouldn't blow off going down the highway.
What are your thoughts? What have you done?
Thanks

[lfhoward]

I used those interlocking foam gym mats. They are not too expensive and you can cut them to fit. They’re also not bad on the feet when it’s cold outside.

[CoventryKid]

I installed a grid of 2x2s (actually 1.5x1.5) on top of the factory floor. Then 1.5" rigid (pink) insulation in the cavities, skinned with 1/2" plywood, then foam-backed lino as the finished surface. Only area where it shows is at the doors (ramp at back and side door).

If I were to do it again, I would put rigid insulation UNDER the factory floor. More effort required, but asthetically would be better.

Hope this helps.

[flboy]

This is how I did it back in March. 2 inch foil backed styrofoam glued to underside with liquid nails and sealed well with expanding foam. Seems to work well and protects underside from road elements.

It was very easy to do. I did have to cut in half to get the ends tight. Very tight fit held it in place, but liquid nails ensure it will go nowhere and the bead of expanding foam for good measure.

R7.7 Foam... made a noticeable difference with cooling. Not tried in winter yet.



The underside as is.



Cut to fit with a circular saw.. much easier than trying to cut through 2" foam with a razor. It made easy work. Each sheet of 4ft. by 8ft covers between three floor Joists. I did the whole trailer with 3.5 sheets. Very inexpensive (~$20/sheet) for the total benefit of R7.7 insulation and protecting the plywood. For those up north, no reason why you couldn't double up for 4 inches thick (R15.4) . Plenty of room left for another 1 to 2 inches more.



I did go back and clean up the mess with a razor blade after the foam cures.




I hope this helps.

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[Karebru]

Thanks, guys.
That's some thick foam there, flboy. Plenty of room for it. Your method seems sound.

I'm putting it on the back burner for now.
I had to re-insulate the underside of a 14x70 that my wife and I were living in. Goats will eat ANYTHING.
It was a chore then, and I'm 35 years older.

If and when I get to it, my mechanic buddy might let me use one of his lifts on a Sunday. That would sure make it easier.

[McDave]

I have been looking into the spray foam method for the floor and also for this old house, (+125yrs). It seems that it is something you can DIY.



This site has some info that is easy to understand. https://sprayfoamkit.com/ms/hp/

McDave

[Karebru]

That would be great, if it wasn't so pricey. Yikes!

[flboy]

That would be great, if it wasn't so pricey. Yikes!

I could see that being great for a wall or area that would captivate the foam during application. I do wonder how well it would work spraying overhead such as underneath the trailer. Probably really messy?

This seems like a great option for those who have already built out thier CTC and now want to insulate walls and ceilings when panels are already up and walls built and etc..

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[aggie79]

ATC offers an option on their toyhauler for spray floor insulation:



From the slight overspray on the torsion axles, it appears that this is done toward the end of assembly. They probably have an access pit to provide room to do the work.

[McDave]

Yeah, it looks like about 300 bucks for 2" for a 6x12. And you know it will be a sticky mess. Rigid + Great Stuff to seal it up probably better all around for DIY. It has got to make a difference though, both hot and cold... and damp? I wonder how much difference just a moisture barrier like Rhino Liner would make? Could be significant. Still a mess to install and ? R value. The foil should give a moisture barrier unless punctured or saturated/peeling. So maybe Foil/Great Stuff/Rhino type waterproofing? Or foil foam + coroplast?

McDave

[Karebru]

Living in swamp and monsoon country, I thought about the moisture issue when I started. I pulled up my non-pressure treated plywood and gave the underside two heavy coats of spar urethane.
On the inside, it has the one piece PVC diamond plate, which I assume serves as as a membrane.
I'm thinking I'm set as far as a moisture barrier goes.
I guess a few heavy rugs, even though they wouldn't be a hundred percent coverage, would add some R-value.

aggie79 » Mon Sep 17, 2018 2:31 pm
ATC offers an option on their toyhauler for spray floor insulation:

Being an option, they must not feel that it's an absolute necessity... Or it could just be a marketing strategy.

[McDave]

I can testify to insulation value of a wool rug + diamond PVC. My wife got one on clearance from the furniture store she works at. It was 6' x 8', the exact size of the cargo area of my toy hauler. The difference was incredible as far as cold transmitting through the floor and probably heat as well. Made it much, much easier to keep warm in below zero temps. Wool is a great insulator, but not cheap. But you may be able to find a similar deal on an "ugly" rug? Beauty is in the eye of the beholder, so who knows?

McDave

[Dano-Mich]

We used the foam squares in our 7x12 in Wyoming in December. Coldest night was -12 I think. The foam DID help for sure, but my next trailer is going to have 2" rigid foam insulation underneath at some point.

[Pinstriper]

I can testify to insulation value of a wool rug + diamond PVC. My wife got one on clearance from the furniture store she works at. It was 6' x 8', the exact size of the cargo area of my toy hauler. The difference was incredible as far as cold transmitting through the floor and probably heat as well. Made it much, much easier to keep warm in below zero temps. Wool is a great insulator, but not cheap. But you may be able to find a similar deal on an "ugly" rug? Beauty is in the eye of the beholder, so who knows?

McDave

I bet the rug really ties everything together.

[McDave]

Well ya know,
My bride has impeccable taste. A simple but classic color scheme lends itself to a feel of warmth and luxury that really is priceless and a certain degree above the average. Slate walls, sculpted black border with taupe inset rug, and a taupe headliner with solid wood trim detail throughout. A treat for the discerning eye. Behold elegance through simplicity, richness and affordability.




McDave