Styrofoam beneath carpet

[southpennrailroad]

Thinking of the 1" foam beneath the trailer floor. Then one on top as well. I bend alum for window trim and could bend a piece to fit the foam beneath the trailer to deflect the air past any openings that could catch the boards beneath. Like a Z channel. Maybe put alum over the surface facing down to help keep any cold wind from coming up the boards to the wood. Really seal in the wood mainly at the walk area near the door. Pizza and Egg Nog tonight UMMM

[S. Heisley]

That sounds like it might help without you having to crawl around on the cold ground too much. If there are any cracks around the walls or floor boards that cause drafts, you could get some of that insulation in a can and spray it in those cracks, too. Enjoy your pizza and eggnog.

[astrotrailer]

I first undercoated my floor. I ripped some 2x4 wood so it was 2 inches wide. I put the wood just inside the perimeter of the metal frame under the floor. I also ran wood down the center from front to back. I then cut 2 inch rigid foam to fit under floor in all the spaces between the added wood and the metal frame. I cut the pieces so they went in tight enough so they had to be forced into place. I cut down a couple of 4x8 pieces of the fiberglass panels you find in Lowes. I used screws with rubber washers to screw the fiber glass to the wood. I put a thick bead of silicone on all the upper edges of the fiberglass before I screwed them in place. The fiberglass panels help protect the foam and floor from water and rock damage.

Inside the trailer I put 1 inch rigid foam under the plywood walls and between the roof supports. I put 1/2 inch closed cell foam on the floor, ramp door and 2/3rds of the way of the side walls. I covered the foam with carpet. I covered the entire ceiling with 1 inch closed cell foam so my head wouldn't bump on the metal supports. After all that work I have 1.5 to 2 inches of insulation on all outside surfaces.

I installed a forced air RV furnace with heat exchanger and outside vent for combustion air and exhaust. The the insulation helps retain the heat and keeps the furnace from cycling on too much. I have used the trailer the winter without any condensation problems. The insulation also allows me too sleep in until after 11AM in the hot summer after doing astronomy all night. My album has details on my furnace installation.

[mdvaden]

I'd go with single or double layer carpet pad if it was carpeted.

The hard foam sheets would work under thin plywood though without much crushing.

[southpennrailroad]

I'd go with single or double layer carpet pad if it was carpeted.

The hard foam sheets would work under thin plywood though without much crushing.

Thanks

So your saying that once I install the Styrofoam insulation that I would re mount the luan and then tack on the carpet to the luan?That would help insulate the walls besides the Styrofoam. I then should have no water problem. Just leave the vent open to get rid of the water. Also keep the fan running.

[eamarquardt]

South Penn,

Find a more efficient electrical heater! They are out there.

Don

According to my favorite "Rocket Scientist" brother-in-law (PhD, ME, emphasis on heat transfer) all electrical resistance heaters are "created equal". One watt of electricty in, one watt of heat out. You can't alter the "laws of physics".

Cheers,

Gus

[mdvaden]

I'd go with single or double layer carpet pad if it was carpeted.

The hard foam sheets would work under thin plywood though without much crushing.

Thanks

So your saying that once I install the Styrofoam insulation that I would re mount the luan and then tack on the carpet to the luan?That would help insulate the walls besides the Styrofoam. I then should have no water problem. Just leave the vent open to get rid of the water. Also keep the fan running.

I was referring to using either carpet pad or hard foam on the floor. With a thin plywood under carpet if hard foam was used - just an idea. But my own preference would probably be carpet pad since its going to have some insulation value.

[Dusty82]

One of the most popular mods done in pop-up trailers is to put a layer of Reflectix under the foam mattress. It's not used so much for its R value - the Reflectix reflects your body heat back up through the mattress without adding a lot of bulk or weight. You have to remember that on a pop-up, the mattress lays directly on top of a sheet of 1/2" thick plywood or OSB with nothing else underneath. Adding Reflectix really makes a big difference.

Two strips of the 24" wide Reflectix taped together long edge to long edge would cover the whole floor area in a 4' wide tear and weight maybe a pound. The great thing about that is that it's not a difficult or permanent mod. Installation uses a roll of tape and a pair of scissors, and it can be removed at will and used for something else if needed. Of course if a person wanted to put it under their carpet, they could do that too. It's not expensive and you can find it at both of the big box home improvement chains.

[Conestoga]

Hi folks. In our little trailer we have 1" foam with reflective foil backing. One layer of this foam covers the floor, and an outdoor carpet covers it. This does an impressive job of retaining heat. As you can see in the pic, it does have some slight dip/dents in it (mostly from handling it, believe it or not) but when the carpet and cushions are in there it is difficult to damage the foam... We hauled our bikes inside the trailer last year, and may do it again this year. Everything comes out, down to the bare floor for cleaning/airing.
I can stand (bent over at the waist) inside our camper and I would have no reservations walking on this foam + carpet in a standy. Disclaimer: I am 125lb.

[Bikerman]

What makes blue board or any insulation work is the air space traped inside that hinders heat transfer. Eventually, walking on the foam will break it down and compress it and it will lose its effeciency. I would suggest you go with standard building practices and use the blue board on the floor and use a subfloor over that with stringers (2x2s mentioned above) to carry the weight of the subfloor plywood or CDX. Keep the span of the plywood on top of the "joists" at or less than 24". I would paint the underneath side of my subfloor and the joists with Kills to seal it from mositure. I would not screw the joists into the floor and use liquid nail to glue them and there will be no way for them to move after the subfloor is screwed in them.

Your rim josits (outside stringers next to the walls) should butt against the wall tightly with the subfloor. You could caulk around the wall and floor. Carpet pad, I'd suggest a Hi D Foam pad, not a waffel pad putting the plastic side down over the subfloor and carpet over the pad. You could also just use double face tape with a rubber back carpet or indoor-outdoor. I would not glue carpet down to the subfloor as it would be a mess to replace later on.

Initially, I would then build my walls right over the carpet by screwing down my bottom wall plate (a 2x2). This is how interior walls are set over carpet in mobile homes. If you need to replace the carpet later on, just cut it and pull it out as necessary (easier). I'd then use 2x2s as wall studs, use foam to isulate the walls. This will be more efficient than batt insulation compressed against the wall. Then use plastic sheet as a vapor barrier and cover with luan plywood or whatever panneling you desire.

Don't forget to run your wiring. If I were going to run any wiring under the floor for any reason, I would lay conduit in next to my joist and use a couple of hangers to hold it in place, for 12V I might just use PVC. You don't want any wires rubbing together from walking on them. I'd do the same for any water service line too, like a garden hose. If you run 12V wiring across the trailer, side to side, I would simply cut the joist to butt against the conduit and not notch it out or drill a hole through a 2x2 joist as it would eventually break anyway and the floor can span that 1/2 inch without a problem. I would not run shore power that direction in romax, I would rather go on top and go back down the other wall. If it ever had to be replaced I believe it would be easier to fish a new line that direction than running under the floor. But keep replacement in mind and you might make a floor route work for you. I have a steel floor, I wouldn't want 120V running anywhere near my 12v system extept to be fused in a box. I'm getting way off topic sorry!

I'm not going to run anything under my trailer as I intend to use it off road, so I don't need anything to be snagged on a trail. So any drain will go out just above the tounge to drain any tank. Same with water supply lines.

Anyhow, that's how I'd do it......good luck!