Coroplast/Rigid Foam for Floor Insulation

[Evan Friesen]

Just curious...I know a number of people have taken steps (or wanted to take steps) to improve insulation on the shell of FGRV's.

I have seen a few references to using carpet to insulate the floor, as it is commonly accused of being the "weakest link" in keeping our little eggs warm.

Has anyone used (or considered using) Coroplast and rigid foam insulation as a barrier/airspace insulator under the belly of our beasts? I know a lot of "stickies" are insulated on the bottom this way. It seems like it could be a cheap and effective way to insulate the floor.

Maybe I should ask this question towards the end of summer when more campers are thinking about keeping warm...but I saw someone asking about floor insulation on another thread and thought about it now...

Anyways, our family generally has more time to camp in spring and fall - so maybe we will consider this when we rebuild the frame of our Boler in the near future. Just thought I'd share my thoughts if nothing else...

[cpaharley2008]

I think that is a great idea since you will have access in rebuilding. Otherwise it will be a PIA to work while on the frame. How will you attach it?

[KevinPete]

One disadvantage of coroplast is that the channels are open, and seem to attract water and dirt. I've sealed the edges with tape, which works to an extent. Caulk doesn't work, the expansion and contraction of air in the channel will either suck the caulk in or push it out. Under a floor I'd stick with rigid foam, maybe 1" PIC with a foil face.

[Brian B-P]

I can't imagine Coroplast as very effective - or cost-effective - insulation, although it's an interesting idea as a protective cover on the bottom of foam insulation, with the foam in turn on the bottom surface of the floor panel.

[Evan Friesen]

I'm not sure how I'll secure the Coroplast. Maybe self tapping screws with big washers into the bottom of the frame? I'll have to look under my parents stickie again...I seem to recall that is how it was done.

As for cost...I was planning on collecting old political signs from a neighbor, so I'd be getting the Coroplast for free...I'm sure they're only a sore reminder to him anyways. A couple were pretty big! I would probably Gorilla Tape them together and be sure each piece gets enough screws to hold them to the frame.

I was thinking of trying the Coroplast first since it'll be free hopefully. If it wasn't making a significant difference, I would get rigid foam and glue that to the fiberglass underside of the floor.

Do you think the Coroplast on it's own would perform as well as the Ensolite on the shell? The trailer will still always have weak points in insulation regardless of how well the floor is insulated. I just notice the floor seems to get coldest because I stand barefoot.

The more I think about this the more I think that maybe it'll be less work to put on a thicker pair of socks.

[KevinPete]

I really don't think the coroplast is going to insulate at all. You need a "dead" airspace for insulation, coroplast's voids are open on both ends. Even if you sealed the edge, the R-value would be very low. It might protect foam from dings/splashes, and allow easier cleaning, but then again the openings need to be sealed or dirt and water will just keep getting in there.

[Evan Friesen]

Originally Posted by KevinPete

I really don't think the coroplast is going to insulate at all. You need a "dead" airspace for insulation, coroplast's voids are open on both ends. Even if you sealed the edge, the R-value would be very low. It might protect foam from dings/splashes, and allow easier cleaning, but then again the openings need to be sealed or dirt and water will just keep getting in there.

Why do many RV manufacturers use Coroplast under their trailers? Am I mistaken in assuming they use it for insulation by creating dead airspace. Is it only to protect the plywood floor/frame from getting wet?

In my head, the ribs/voids are more for adding rigidity to the material used to create the dead airspace. It wouldn't be hard to put some duct tape around all the edges though. The main dead airspace would be between the coroplast and the floor of the trailer. My idea was to secure the Coroplast to the bottom of the frame to form as airtight of a dead airspace as possible.

[KevinPete]

That might work if it was sealed off. I'd still get warm slippers, though.

edit: Forgot to mention Paul Elkins, the man who does some cool stuff with coroplast. He seems to have taken most things off his site, but his youtube channel (link above) still has it all there.

[Brian B-P]

Originally Posted by Evan Friesen

Why do many RV manufacturers use Coroplast under their trailers? Am I mistaken in assuming they use it for insulation by creating dead airspace. Is it only to protect the plywood floor/frame from getting wet?

I think that it is an enclosure material, not insulation. When it is run from frame rail to frame rail, it encloses the entire volume the height of the frame, which conventionally contains the tanks and plumbing; those are the components to be protected, not the floor or frame. I don't think it is for insulation itself, although it can contain and protect insulation.

Originally Posted by Evan Friesen

In my head, the ribs/voids are more for adding rigidity to the material used to create the dead airspace..

I agree - Coroplast is "corrugated" for the same reason as corrugated cardboard... for structure. I believe it was designed for making signs, but it has found other uses.

Amusing trivia: Wikipedia says Coroplast is a trademark of the Jim Pattison Group, which was the last owner of Boler.

[Ed Harris]

I found some of those 1/2" thick floor tiles like used in playrooms they lock together like a jigsaw puzzle to create the floor surface.

The ones I found have an indoor/outdoor carpet on one side.
I have them cut to fill the floor area in the Casita and it works amazingly well to keep the floor warm in any weather I have been in including trips into the teens.

They also protect whatever is under them and provide a nice soft cushioned surface to stand on while barefoot too.

I found them at Sears of all places in the tool area.

They also just lift right out for cleaning or replacement.

[Donna D.]

A number of years ago, pre-hack, we had a thread about an owner wanting to use his Scamp as a ski shack in the winter. Needlessly to say the floor was cold. He bought blue styrofoam and glued it to the bottom of the floor, working around the frame, etc. like a puzzle. He was quite pleased with the "warming" result. The styrofoam wouldn't absorb moisture during wet travels. Now, you know what I know

[Ron in BC]

My concern would be creating a barrier that could get moisture trapped between the foam and the floor. Unless it was well sealed it could be problematic.

[Evan Friesen]

Originally Posted by Brian B-P

Amusing trivia: Wikipedia says Coroplast is a trademark of the Jim Pattison Group, which was the last owner of Boler.

That is so cool!!! Very trivial trivia too...my favorite kind!

Originally Posted by Ed Harris

I found some of those 1/2" thick floor tiles like used in playrooms they lock together like a jigsaw puzzle to create the floor surface.

Cool solution. I just like my wood floor so much...

Originally Posted by Donna D.

Now, you know what I know

Thanks Donna! I may end up going this direction in the end!

Originally Posted by Ron in BC

My concern would be creating a barrier that could get moisture trapped between the foam and the floor. Unless it was well sealed it could be problematic.

That is probably a very valid concern. I hadn't thought of it keeping moisture in.

I should ask questions here more often! You all can do my thinking for me!

[Ed Harris]

Originally Posted by Evan Friesen

Cool solution. I just like my wood floor so much...




I should ask questions here more often! You all can do my thinking for me!

Thats the real beauty of these tiles though.
Two of them would cover most of the usable floor surface and only when you need them for extra insulation.
They are lightweight and flexible and just sit on your existing floor like a rug but they actually do provide enough insulation for your floor to make a difference and then can come out in 2 seconds when it is warm again.

[Luis]

I am planing in installing 1/2 inch hard foam panel between the FG bottom and the new 1/2" plywood flooring. This way I can finish up the floot with lino, carpet, plastic tiles, laminate flooring, etc , nail/screw cabinets to the plywood as needed, etc. and still have thermal insulation on the bottom.

My concern is load bearing so I will leave certain sections of the foam layer done with plywood strips that support the weight of the floor and use.

Will share some pics as we get down to construct.