Insulating The Bedroom Walls

After putting the walls up in the main room we started working on insulating the bedroom walls. To keep the insulation from falling out the front bedroom wall, we tied strings up on the outside of the rig.


As I wrote in a previous post, the new insulation we chose is Thermafiber SAFB mineral wool. We purchased the mineral wool in 2 inch thickness and 1.5 inch thickness. The original bedroom walls are 1.5 inches thick and we made the walls thicker by another 2 inches for extra insulation. This means that we need two layers of insulation in the bedroom. Wear rubber gloves and a long sleeve shirt when dealing with the mineral wool! They are as irritating to the skin as fiberglass batts. Andrew and I worked as a team - he would measure out each wall section, hand me the measurements, I would measure out the mineral wool sheets, mark it, cut it and hand the cut pieces to him to install. We found that a serrated knife (it doesn't have to specifically be this 1990 infomercial breadknife) works best for cutting the mineral wall batts. Smooth like butter. I used a piece of scrap wood as a guide.

Here's a picture of Andrew measuring sections of the front bedroom wall. The next photo is the view of the insulation from outside the trailer. You can see the underbelly wrap (black fabric) is holding the bottom pieces in place since there's no outside wall yet. The last photo is the view from inside the rig; the extra space is for the second layer of 2 inch insulation.

Once both layers of insulation were in, we covered that wall with plastic as a vapor barrier. The vapor barrier prevents the humidity inside the bedroom from condensing on the inside of the walls. (For some reason we already had this large sheet of plastic laying around our crawl space.)

Trying to wrangle this huge sheet of plastic was a pain in the butt! Eventually Andrew and I got it straightened out, pulled tight and then stapled it to the wall beams. Once that was done we cut the extras off. 

We used brads to put luan up on the inside of the front bedroom wall and used a router to cut out the window hole.

We realized that the side bedroom window holes can't stay as is (picture on the bottom left). We have to cover up the inner wooden frame (the one that creates the square shape with rounded corners) because the flanges of the actual windows that go into the wall aren't square shaped and aren't wide enough to cover the entire inner wooden frame. So we glued pieces of luan over the inner frame to keep any parts of the inner wooden frame from showing after the window is installed. Instead it will be a smoothluan surface instead of crummy 1" x 2" wood that's visible.

These are the wires from the trailer harness that gets plugged into the truck. The wires control trailer lights, brakes and turn signals. Mixed in those wires are also wires for the A/C receptacles that will be in the bathroom nightstands. We laid them out because they will get covered by insulation and luan.


Putting insulation in the rest of the bedroom walls along with the sink area and shower. Then the  plastic sheet for vapor barrier went on.

While Andrew and I worked on that, Jerud had cut out the parts for the fridge stand. We decided to install a stand because it will hold the fridge in place and make the fridge taller so we don't always have to bend down to get things out of it. The empty space under the stand will make a great place to store shoes! In the picture on the left, Jerud is drilling holes in the platform where the fridge will sit and be attached to.

Meanwhile the world outside got a dusting of snow and the dogs decided to eat it.


Thank you for making your Amazon purchases through our affiliate link.