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Insulation and Waterproofing

Let's Put Some Real Insulation in This Thing!

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"The only limit is your imagination"

Here you will see my efforts to not only insulate the trailer from the elements, but also the application of waterproofing membrane and an overall vapor barrier. Should be able to heat it with a candle!

After seeing the miserable poor excuse for insulation that General Coach used, I wanted to actually insulate it rather than drape a thin layer ineffective nothing over it all. They didn't even fill the cavities. 

The floor is framed with 2X3. I used R-20 split in half laterally in there to arrive at R-10. R-12 is meant to fill a 2X4 cavity at 3 1/2". Insulation loses R value if you compact it too much. It needs to be loose to do its job. The walls are framed with 2X2, nominal 1 1/2" I took R-12 and split the batts in half to arrive at R-6. All the walls are done this way. Because the roof is 2X6, ripped to 4 1/2", tapering down to 2 5/8" at the outside, I started with R-20 in the center, and split it off as I went to about R-10 on the outside. I compressed it slightly, not much.

Click on Images to Enlarge


The Floor Insulated:

The floor was insulated early, as I had to put the new plywood down before continuing. The floor page shows more.


The Center Floor Before:

That last piece of floor again. Thought I'd show the insulation here. This is before, with that flimsy factory stuff.


The Center Floor After:

The flat aluminum sheeting is the heat ducts. There is a layer of 3/4 styrofoam under the duct area.

Waterproofing: As mentioned back in the re-assembly, I used Blueskin to keep the water out of vital areas. A bit more on that before we get into insulating it. I showed you what I did to the floor before doing the walls. More detail on that here. Corners of an RV are vulnerable to water entry. They don't do much of a job of sealing them up at the factory. Basically, run the siding to the corners and put a narrow trim over it, a feeble attempt and sealing it and hope for the best. Then when it leaks in a year they blame the RV owner for not maintaining it... Yeah, well....

Anyhow, I thoroughly sealed up the corners top to bottom, and applied the Blueskin to a number of other places, as you will see as we move forward. OK, back to the task at hand.


Wheelwell Housing Fastened:

Up until now the galvanized wheelwell had been just hanging there. Once the Blueskin was in place, I stapled it on there with the 1" X 1" staples


Sealing Corners:

I used 6" Blueskin, so thats 3" each way. I ran it down the back first, then the side.


Sealing Corners:

This ought to help avoid corner rot if water ever gets in there.


Note To Self!!:

Oops! - Bob - be sure to keep your fingers out of the path of a fresh knife blade ! !

They're sharp you know! Tsk Tsk....


Top Of Corner:

Corners of RVs are especially prone to water entry. I made sure they were well wrapped with waterproofing membrane.


Waterproofing Membrane:

I used Blueskin to seal things up as I did around the floor perimeter on the Reassembly page. It is 100% waterproof.

Lets start insulating the outside!


Start With The Back:

Remove the siding for the upteenth time. Ready to get going on insulating it. Takes a lot of time to unwrap it all to work.


The Back Insulated:

I very carefully filled every bit of all cavities to ensure maximum sealing up of everything. Ready for vapor barrier.


Window Surround:

I used Fome-Cor around all windows to ensure an even, snug fit of the window once it gets re-installed.


The Tyvek Test:

Tyvek, a weatherproofing membrane widely used in new construction.

I ran the hose at a trickle for about half a day on a piece of Tyvek tacked to scrap wood. Not even a drop came through.


Tyvek Vapor Barrier:

Back end: this was the first to be covered. Now it's all sealed up well. This stuff breathes but won't let water penetrate. I had 2 rolls of it in the garage so why not


Side View Before Insulation:

Ahhhhh - all that nice new wood finally being covered with insulation! I forgot the Fome-Cor around the windows and didn't notice until much later. Description follows with other pics.


Side Partly Insulated:

This is called using what you have on hand for a nice array of different colored insulation!


Closer Shot:

One thing I had an abundance of is part bundles of insulation. Most guys I work with just scrap the leftovers. Such waste!


Side Closeup:

I took many dozens of pictures like this so I can view later if I need to remember a wiring or other detail.


Side Done:

Isn't that colorful? But it's effective. I paid a lot of attention to making sure every little nook and cranny was completely filled with insulation.


Side View:

Fortunately for me, there was very little wind today. This stuff is a bear to work with in the wind! Here you see it partly covered.


Side Done:

One side and the back finished. I will cut the openings out later. Goal is to get as much insulated as possible before it rains again.


Second Side:

All ready for insulation. Note backing for blinds and more, wafer screws to all things inside to keep wall panels tight to things, wiring done and Blueskin detail.


Side Finished:

All done and ready for vapor barrier. Note the duct tape on the side. Insulation wouldn't stay put. I got tired of putting it back after picking it up off the driveway.


Above Door:

This heavy duty piece of aluminum sheeting is to help stiffen the top of the doorway to help prevent stress cracks. The original was a piece of galvanized.


Clearance Light Detail:

I took these pics so I could review how I solid blocked for the clearance light screws. I wired it for 2 filament bulbs, one to blink with the turn signals.


Light Switch:

All the plugs and switches on the outside wall got the Blueskin treatment to prevent air infiltration. It all helps when it comes time to heat the thing.


Another Clearance Light:

I don't like things just screwed to the siding. Everything has backing. Lots of careful planning and writing notes every time I thought of something.


Fome-Cor Around Openings:

This stuff is a high density foam with perforated foil on both sides. The original installation had something similar so I duplicated it. It will help with the thermal barrier for the windows.


Tyvek Application:

9 foot roll is perfect for this application. Roll it out a few feet at a time, tack it in place on the top and carry on. I am picky, I want it all nice and flat and even. No wrinkles, can't have that!!


Tyvek Application:

The whole side rolled out and tacked in place. I went along the top first, ensuring it was straight and even. Then pulled the middle straight down and worked out the the ends from there.


Top Of Doorway:

Same at the top - if water enters, I will see it come in instead of it being hidden until damage is done. If water comes in, it will show up on the floor, as the door framework is completely sealed.



Many trailers I have seen have water come in by the door.


Bottom Of Doorway:

Again, completely sealed so no water can get into the floor or walls from here. Putting the Blueskin over top of the lino makes it impossible for water to get into the floor from the top.


Front End:

The front is now ready for insulation. That loop of wire up above is for a hitch area light, to see the front at night.


Front Wiring:

More detail pics of where stuff goes. Wiring, and the center support for the propane regulator. See the wafer screws.


Front Done:

There's the multicolor again! And also the Fome-Cor around the window. Ready to cover with Tyvek.


The Roof:

I had to climb up on top of my 2 storey house to get this picture. I was going to rent a helicopter, but this was cheaper! Somewhere a bunch of pics down from here you'll see my extension ladder against the house to get up there for all these pics.


Good Roof Shot:

I stood on the lower roof of the house to grab this pic. All ready for insulation.


Solar Prewire:

I knew I'd want to put some solar on the roof, so took pics of the exact location of the wires. They run down the wall between the bedroom and the bathroom. It's a good a place as any to mount the control panel later. You can see a few water stains where my tarp leaked a bit.


Speaker Cover:

I covered all the speakers with Tyvek and taped it down. This will keep insulation dust out of them. You can see those screws in many of the pics. I didn't spare the fasteners, that's for sure.


Wiring And Backing:

Bathroom to bedroom partition is under that row of screws, Wood backing is for the hanging bathroom door hardware. Note the wafer screws fastening the ceiling panel to the partitions.


Roof Closeup:

If you look close here, you can see the vent pipes for my grey and black tanks. I left them short for ease of installing the roof skin. A coupler, a few inches of pipe and a bit of glue will put them up higher.


Roof Insulated:

All done, except the ends. I still have a little framing work to finish that I've been putting off as long as I can!


Roof Insulated:

I stood on the front of the trailer for this. A lot of the other pics were taken standing on top of my truck rack.


Roof Insulated:

And another picture taken from standing on the back of the trailer. Again, should be able to heat this thing with a candle when I'm done!


Top Ends:

I finally had to finish framing the little curved pieces for the ends and insulate the area.


Extend The Blueskin:

I ran the waterproofing up over the top of the curve for added protection. Now ready to insulate and button it up.


Top Ends:

Now with the insulation in place, I can finish covering it with the Tyvek. This chapter is nearing its end, finally!


Back End Top:

Same deal as the front, framed in the curved pieces and installed them, insulated and finished the Tyvek.


Completely Wrapped:

There! The whole thing is done. Tuck tape has sealed all the joints. Great stuff, it sticks very hard to everything and forms a watertight joint.


Back Detail:

Everything is all taped up and sealed. I even did around the tail light wiring where it comes out.


Front View:

Look close - I painted the hitch with Tremclad rust paint. I got tired of looking at the rusty metal. Going to crawl under and do the whole frame.


Another Finished View:

If you zoom in and look close, you will see that I cut a small piece of Tuck Tape to cover every staple. Boy, that was sure a lot of work!


Front and SIde:

And . . . one more picture. what can I say? except ... One more picture! Note the ladder at the house roof to get the pics! Mother used to call me part monkey...


Window Opening:

Time to cut the Tyvek and staple it down. First I cut it, leaving a flap, then folded and stapled it into the opening. Everyone knows one of the worst leak points is the widows. Water will sneak in and run inside the wall un-noticed.


Sealing The Opening:

Then I went all around with Tuck Tape and made sure it was 100% sealed, right into the inside of the wall, so water cannot find its way into the inside. If water gets through the window somewhere, it will be visible inside.


Grab Handle Recess:

I think the grab handle had a light in it. Can't recall for sure what this wiring is for.


Outside Plug:

I sealed up the plug too. High chance of water getting in while doing 60MPH down the highway. Gotta cover it all.


Roof Vents:

I did a thorough job of sealing the roof vents and A/C opening so any water that gets in will not enter the framing.


AC And a Roof Vent:

The Tuck Tape is a wonderful product. Sticks to everything, won't come off and ensures the framing will stay dry.

Wow, that was sure a pile of work! But she is all insulated and sealed up tight now. It could rain on it like this and aside from the openings, it would stay dry inside.

Next up, onto the siding.

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