The carpet would not be enough, and as ICECM stated, the rigid foam insulation would work well. You will have to cover it with some plywood for strength. Carpeting can be reinstalled over the newer flooring.

A conventional mattress or one of foam/rubber has better insulating qualities than an air mattress and will be warmer to use.

Gard

I helped a friend modify a DR, GN trailer into a sleeping area. The original floor of the sleeping area only had carpeting installed. Since the owner's requirements only included occasional overnights, insulation and comfort were more important than cabinetry and trim molding.

The carpeting was removed, and  10 OZ carpet padding, the kind with memory foam, was glued to the floor. A second layer was added and plastic was put over everything, then carpeting was reinstalled. It was very comfortable and with outside temps just below freezing, warm to the touch when inside heat was applied.

Gard

That's a good point Terri. The carpeting in my friend's trailer easily ripped out when we used a hot air gun to soften the glue. If it doesn't remove without difficulty, I see no reason why it couldn't be left in place.

The only problem I can envision, is attaching the new materials to the floor around and over the edges of the existing carpeting. This could be accomplished by the mechanical application of trim strips and hardware, but I'm loath to drill holes into the skin of a trailer.

Just laying new material over the carpeting without securing it, will be like placing an area rug over carpeting. It will move about, the edges will  be curled, and it will look exactly like it is, a quick fix.

An extra hour spent in the beginning of your upgrade with a hot air gun, I think, will make your finished project a lot more pleasing, now and in the years to come.

Gard

This guy's website spells out how to insulate everything.  I used it and had absolutely no condensation issues when I was done, plus, when camping in the trailer I was warm and cozy.  One other benefit of insulating really well is that is makes the LQ really quiet inside.   Check out the website.

http://todd.redwrench.com/index.htm

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We needed the hot air gun to remove the carpet on the bed and bulk head.  We were then able to use the foam board insulation between stringers that were glued to the aluminum, plywood was installed over that and a new application of carpet.  I use a mattress (brand new) from a convertible sleep sofa and am able to store a couple of pieces of plywood under the mattress in order to make a table for outside the LQ when we set up.

It made a huge difference in sleeping comfort.  Without the insulation it was like sleeping in a refrigerator.

Gard,

I like your idea of foam padding, plastic, and carpet glued down--it sounds like something I could do.  Could you please tell me specific products you used?  The gooseneck (sleeper) portion of my trailer is just painted steel.  Would I need to do any prep work first?  Anything you can tell me is very greatly appreciated!

Mary

We removed the factory installed carpeting using a hot air gun to soften the glue. Using acetone, we cleaned and sanded the floor about 1 1/2" around the circumference of the goose flooring area. Using a polyurethane construction adhesive, we glued down a continuous band of firing strips, that were ripped to aprox 1 1/2" x 5/8", around the flooring circumference. The top edge of the furring strip, that is seen when looking forward over the bulkhead, was rounded over with a router to remove the sharp edge you would encounter while climbing into the bunk.

We obtained some carpet padding remnants that were 10 oz.. 8 oz is a common weight, and we were fortunate to find this heavier weight that included an additional  memory foam surface. We cut and fit the pieces, and placed them within the floor area, two layers thick, being careful to fully overlap any seams. The padding was cut to fit within the perimeter of the outside furring strips, and its total resulting thickness was slightly proud (higher) than the wood. A sheet of poly was placed over the padding and continually stapled around the edges.

A new carpet remnant was purchased, and we had one edge bound. Placing the bound edge on the floor, against the front vertical edge of the furring strip, above the edge of the bulkhead, we stapled the carpeting continuously along its length. This is the exposed edge you see when standing in the LQ, looking towards the nose of the trailer. Placing the carpeting over the vertical edge of the wood, totally encloses and hides the end of the new flooring with a finished edge.

The carpeting was then stretched forward, towards the nose and sides, and continuously stapled around the remaining edges. A mattress was subsequently placed on top. The redone area is comfortable to crawl around in and maintains the inside temp quite well.

The  vertical bulkhead was finished somewhat differently. We glued the same furring strips around its circumference and added vertical strips every 24". We glued in fitted pieces of foil faced rigid foam. Everything was covered with 1/2" plywood, and more carpeting was glued and stapled to the plywood. We used contact cement for the carpeting on the vertical surface, and stapled the circumference.

The floor was fitted out with sleepers 3/4" thick, 16" on center, with a continuous edging of the same. Some electrical wiring was routed, no plumbing was fitted. Rigid foam was installed, and poly was placed over the surface. 3/4" OSB flooring was fitted and screwed to the sleepers. We elected not to glue it down for possible access in the future.

Urethane sheet flooring was then added, and sealed around all the edges with silicone caulking to prevent moisture leakage.

Hope this helps 

Gard

Thanks that helps me. I hated the idea of putting screws in where I could see them after I cut them off. I am going to try the glue with the furing strips. I already insulated and put the plywood on the dressing room floor last summer with carpet laying on it until I decided what kind of flooring I wanted to put in it.