Last year an acquaintance purchased a trailer like ours, but with an unfinished dressing room instead of a weekender LQ. He bought his trailer, with specific intentions of installing a matching LQ as ours. He brought his trailer to my place to be worked on. I have a boat shop full of power tools, he has knees and a body that all works. He had previously removed all the carpeting and interior fittings from the dressing room; we had a clean slate from which to start.

While he was marking the floor off into one foot wide increments, I started ripping 2 x 12 pressure treated planks into 1 1/2" x 7/8" strips. These were cut to encompass the perimeter of the floor, and sleepers were added to the markings that were laid out. In front of the door where everyone takes the first step onto the floor, we added extra supports. When everything was fitted, we took some photos, marked each piece and removed the lot.

Using a random orbit sander with a hook and loop pad, we affixed a green Scotch Brite sheet. Following all of the floor markings, we cleaned and slightly abraded the aluminum flooring, wherever the wood would be placed. Then those areas were cleaned with a solvent. Using a polyurethane construction adhesive, we applied glue to each piece of wood, pressing and fitting it into place, and then removed it. When the adhesive dried to the touch, it was again placed into position. This action was repeated until all the wood sleepers were installed.

Cutting 1" blue rigid into strips that fit between the sleepers, the insulation was pressed into place. The insulation was proud of the sleepers by 1/8", enough to ensure that the flooring would be in constant contact with the top of the insulation. Using 1/2" pressure treated plywood, we cut and installed the flooring using 1" deck screws into the sleepers at about 1' intervals. We started at about 8:30 and just before noon, this was done. The result was a rock solid floor that exhibited no movement or noise.

 A hole was cut into the aluminum bulkhead, and a potable water fitting was installed, with an interior attached hose that would eventually lead to the boot box. A second hole was drilled and a grommet was added for the installation of a battery cable. An external battery tray and propane bracket were bolted to the bulkhead, using stainless bolts and fender washers epoxied to the interior face.

I then started ripping stock for the knee wall. This measured 1 1/8" x 1 1/2" and was standard #2 construction pine/spruce. The vertical studs each had two dados cut into the face against the wall to act as wiring chases. They were placed 12" OC. This was assembled free standing using 2 1/2" decking screws, and placed against the bulkhead for a final fit.

The flooring for the bunk area was then constructed similarly to the entrance floor. Again I used common construction grade sleepers cut to 1" x 1 1/2"  using 16" centers, they over hang the knee wall by 1 1/8" and the ends were flush to the inside edge. The aluminum flooring was sanded and cleaned in the same manner, the sleepers were glued into place, 1" rigid insulation was installed.

The forward faces of the knee wall had glue applied and was set into place. It was screwed onto the flooring, and the bunk sleepers were affixed to the top plate of the wall. 1/2" plywood sheathing was then screwed into place, completing the bunk area flooring. The interior face of the knee wall was covered with Brazilian Cherry manufactured flooring. It is 3' wide, 5/8" T&G, prefinished, strong and quite rigid. By purposely leaving a gap between the insulation and surface of the wall studs, the wood flooring was easily fastened with glue and pin nails. 

Marking out the areas on the entrance floor where the bathroom bulkhead and cabinetry will be, we installed manufactured wood flooring. This was easily accomplished, while using our trailer as a template for all the measurements. This particular style of flooring has a snap joint which involves no fasteners to hold one plank to another. A 15# felt paper was stapled to the plywood, the flooring was laid out and pin nailed around its perimeter, which was about 3/8" short of the final measurements. The edges were continuously caulked.

This year the roof will soon have three large holes. Typical Exiss, right? One for an a/c, an escape vent over the bunk, and a vent, light, fan assembly in the bathroom. We should soon start the interior bulkhead and cabinetry, There are no plans for holding tanks or a shower in the bathroom. A cowboy shower in the first stall will be installed, and a camper commode with an integral above floor holding tank is being sourced. A hot water system, fridge, sink and wiring will be next.

Gard

The knee wall's bottom and top plates are screwed to the bunk and main entry floors. The front face is also glued to the bulkhead.

Other than colour, I don't know of any performance differences among the various rigid foam insulations. The bead types vary a bit.

The sleepers are glued down with no mechanical fasteners.

Gard

We ran the sleepers from trailer side to side, parallel to the knee wall, 12" OC. We purchased 2" x 12" x 8' and ripped them to the various heights, with very little waste. By using tighter spacing, were able to use lighter plywood flooring.

Once your plywood is installed you can run your flooring in any direction. Take some and put them in place in both directions or even on the diagonal. Then you can choose which you like better. I've seen installations of both directions, and each looks good.

Gard

That's what we anticipated when I cut the sleepers a little less high than the insulation. When we were done cutting the plywood and walking around on it, the insulation had crushed 1/8" to the height of the sleepers. When we installed the screws, the plywood was drawn tight to the sleepers with no gaps, and with the insulation helping to support the plywood. It resulted in a very solid floor with no squeaking or noise.

Gard