Tuesday, June 8, 2021

The Insulating Wallpaper Experiment - A Tutorial for Padded Walls!

Once upon a time, many moons ago, I probably mentioned something about my 1957 Henslee 10'x47' trailer being built before the National Manufactured Housing Construction and Safety Standards Act of 1974 and the Manufactured Home Construction and Safety Standards adopted by the department of Housing and Urban Development in 1976, which required mobile home builders to adhere to minimum performance and safety standards. 

No? Did I not mention that? 

Oh. Well, before those regulations, trailer and mobile home builders could do whatever they wanted (i.e. whatever was cheapest to build and looked slickest on the salesfloor), such as shoddy electrical and plumbing, no insulation at all, doors and windows that trapped people inside during a fire, etc. It was a libertarian paradise of total freedom! But freedom isn't free. My trailer cost over $4000 when it was brand new, which is ~$38,015 in 2021 dollars.

My 47-footer was the biggest, baddest new thing in 1957! Before that, the biggest Henslee trailers were 42 feet long.


When I bought this trailer in 2018, the electrical and plumbing had been updated and were in okay shape, and my electrician uncle and I improved it even more. The problem was the whole "no insulation at all" thing. My first year here, if I didn't have the AC or space heaters going, the interior was always the same temperature as outside, degree for degree. I'm not exaggerating--if it was 33 outside, it was 33 inside. If it was 117 outside, it was 117 inside. Basically like living in a tent. On hot days, the exterior of the trailer was cool to the touch from all the AC radiating out, and on cold winter nights, the exterior was warm to the touch from heat radiating out.

In summary, very wasteful, very expensive, and very uncomfortable. I would try to use as little heating and AC as possible to keep costs down, so I was always shivering or baking to death. And with no insulation, it was noisy as hell. I could hear EVERYTHING outside. The details of every drug deal, the meow of every horny feral cat, the crunch of every gravel foot step, and every barking dog and crying baby within a one mile radius. If a Harley ripped through the neighborhood, it sounded like it was actually in my house. There was no sound difference between having all my doors and windows shut tight versus having them all wide open.

Sleeping was impossible.

I discovered the naked truth of the insulation sitch when I gutted the bathroom and kitchen and saw the walls were just 2x2 studs with metal siding screwed to one side and the interior wood paneling nailed to the other, and a few whisper-thin pieces of 1950s insulation crumbling in a few select spots. No vapor barrier, no sheathing, no nothing. Plus, most trailers like mine have no attic, so the roof is the ceiling. Basically, my place was the exact opposite of a passivhaus.

After three years here, I've gradually addressed these problems within my small budget. I've repaired and sealed the roof and coated it with reflective coating, fixed the damaged siding and sealed the seams, added shade screens on the southern side, replaced the window cranks so they closed properly, added caulking and weatherstripping to all doors and windows, and, in the most severely damaged spots, I've re-insulated, replaced the paneling, and/or drywalled where it would blend in with the surrounding walls and not stick out like a janky patch job.

I've tried to make all repairs visually match the existing materials, which unfortunately meant adding "knockdown" texture to the smooth new ceiling panels to blend them with the old ones. Ceilings have nothing to do with this post, but it was a huge pain in the ass and I want credit for it, so I'm posting a picture. See, you can't even tell where the ceiling patch is! #flex

After all that work, the trailer was finally clean and dry, but the interior temps were still subject to wide fluctuations. The trailer just did not hold any heat or AC pumped into it; cooled or heated air immediately radiated out through the walls and single-pane windows. (Here's a really cool explanation of mean radiant temperature, i.e. why your house isn't comfortable even when the thermostat says it should be.)

On top of that, the untouched sections of interior walls looked like the climbing walls at Chuck E. Cheese. Original 1957 birch panels damaged from six decades of people painting, repainting, hanging pictures, mounting shelves, anchoring furniture, punching and kicking walls, removing original equipment, making sloppy repairs, and installing various gadgets and utility upgrades. Much of the trim was mangled or missing too. 


How about slapping drywall mud over a perfectly functioning outlet. What buffoonery is this?


Aside from just setting the place on fire and calling it good, the Internet told me I had two choices:

1) Remove the siding from the outside, insulate between the studs, then replace the siding. 

No way. I just repaired, sealed, and painted all that siding to perfection and I wasn't going to undo it all.

2) Hang furring strips on the interior paneling, insulate between those strips, drywall over the strips, then mud/tape/sand/paint to produce nice new insulated walls.

No way. Too messy, time-consuming, expensive, and too much sanding in a tiny space that I still needed to eat and sleep in. Plus I'd have to unhook and move all the outlets forward to be flush with the new walls and THEN the doors and window frames would all look sunken too and I'd have to think of a design solution for that...

How else could I get smooth, insulated walls without removing all the exterior siding, ripping down the existing walls, or building new walls on top of the old ones? How could I fix this problem in a cramped little space with minimal mess?

In other words, how could I do it not the right way? Not the Bob Vila way, but the Tim Taylor way?

I scoured the Information Superhighway for months until finally I came across some old Brits on a UK remodeling forum. They were talking about Wallrock, used by people living in ancient stone cottages and castles and dungeons with thatched roofs and other places that don't have stick framing. Apparently insulating ye olde family castle is a legit problem in England. 

God save the Queen.

And what on Earth is Wallrock, you ask.

It's a thermal, fire-resistant insulating wallpaper (!) that comes in various thicknesses for different applications. It's half the thickness of a pencil, plain white in color, paintable, easy to install, and looks like a smooth, normal wall when finished. And it makes your place cozy and comfortable.


Wow! I needed this stuff ASAP.

Except Wallrock Thermal Liner is expensive (between $276 and $483 per 33ft roll!), not readily available here in the US (nor could I find anything even remotely similar), and getting enough of it shipped from England to Arizona to cover 500 sq ft of my walls would have cost, like, a couple thousand dollars. On my pizza delivery driver income...


So the official Wallrock product was off the list, but surely I could invent a DIY version. Was there such a thing as plain white paintable wallpaper here in the States? Could it be attached to thin sheets of foam? Were there any foam sheets that could be glued to my walls and look nice and be affordable and not fall off?

Plain white paintable wallpaper, aka wallpaper liner, is indeed widely available in the US. It's mostly used to smooth out rough walls before applying normal wallpaper or to hide the telltale grooves in 1970s paneling before painting. I bought nine rolls of this brand:


Finding flexible, not-too-thin-and-not-too-thick foam with insulating properties was a bit trickier, as foam typically comes in either a few sheets for packing small fragile items or in giant industrial 3,000-foot rolls. It was also hard to tell by online pictures which foams would have a dense enough texture to accept glue on both sides but not so dense and rigid they would flake and crumble like Styrofoam.

Eventually my Google searches suggested the two basic types of flooring underlayment:

I started out with one pack of the blue accordion-style foam to experiment with. When used under flooring, the foil side faces the living space and acts as a vapor barrier. Score! I knew the white-ish stuff wouldn't work because it's too slippery, but according to my experiment, the folding blue foam held to the wall with Roman Pro-543 wallpaper adhesive like a dream, and plain paper held to the foil side beautifully as well. So I bought five total packs of the blue foam.

Now, I didn't know if gluing this stuff to all my walls would actually produce the desired outcomes of stabilizing my home's interior temps, smoothing out my ugly walls, and/or dampening sounds from outside. Maybe it wouldn't do anything at all, or maybe it would look nice at first and then fall off, or maybe it would look like shit and I'd have to start all over with some other solution. I had no idea how it was going to turn out, but if it failed, then at least then I'd have more data points to consider when inventing something else to avoid drywalling my entire trailer.

I guess the title of this post is a spoiler, huh?

I never did get the hang of writing suspense novels.

When friends and coworkers asked how my home repairs were going and I mentioned this insulating wallpaper experiment, every single time they'd fall into a trance and chant, "Ohh, wallpaper? Eww, I HATE wallpaper. I just...ugh. I could never do wallpaper." 

I'd assure them that this was plain white wallpaper that could be painted any color and would look like an ordinary wall when completed, but they wouldn't listen. Their eyes would glaze over and they'd repeat how much they hated wallpaper and would never touch the stuff. Even when I repeated the phrase "plain white," they simply couldn't picture anything but horrible 1980s Victorian revival stuff.


It hurt my soul a little that anyone would think I have such terrible taste, but then I understood why designers now call it "wall covering" instead of "wallpaper," because people become unreasonable upon hearing the latter word, like they're under a spell. I guess like how trailer parks are now called "mobile home parks" no matter what they look like, 'cause people apparently lose their minds over the phrase "trailer park."

Anyway, forget about those people. Here's how to create your very own padded walls!

1) Prep the paneling: First, remove any trim, switch plates, nails, dirt, etc. Fill any holes with drywall mud or caulk, scrape the roughest patches with a metal putty knife, and wipe the walls clean with a damp rag or degreaser if needed. I also sealed small gaps, seams, or splintered spots with butyl tape.



2)  Attach foam: Moving from one area to the next, use a box cutter to cut the sheets of foam underlayment to dry fit. Spread a generous amount of wallpaper adhesive on the blue side with a paintbrush, then press the sheets firmly to the wall, smoothing them out with your hands. Outlets are easy to cut out immediately after gluing. Clean up any excess glue right away with a damp rag.

Dry fit each section first.


Pour the glue on and spread it evenly with a paintbrush. Don't forget the edges and corners!

Stick it on the wall and press firmly. Smooth out any bubbles.

Carefully cut away from outlets and wipe off any stray glue.

Gettin' there!

Butyl tape under the foam for any small gaps or splintered/questionable areas.

3) Tape the foam's seams: Let all that glue dry for a day or two, then tape all seams with underlayment tape (or any thermal tape). Next, take your protein pills and put your helmet on, because your room will now look like the inside of a spaceship:

The stars look very different today.

I know you're laughing, but stay with me here. We're not done yet! And never judge a masterpiece before it's done.

4) Attach wallpaper: Dry fit the white paper first, then use water or glue, depending on whether you got the pre-pasted type or plain. I bought the pre-pasted kind and the instructions said to soak the paper in a tub, but that made a huge mess and drove tons of water into my baseboard area, so instead I cut the dry paper sheets to fit, sprayed them vigorously with water, then smoothed them onto the foil/foam walls with a plastic putty knife with the sharp corners snipped off. I wiped up drips and smoothed everything out with a clean damp rag as I went.

See what I mean about working in a tiny space? No way was I drywalling while also living in here.

Also, be sure to very slightly overlap the seams because the paper will expand when wet, then shrink a little as it dries. I hung wallpaper for a living in my youth so this was old hat to me, but detailed paperhanging tutorials are on YouTube if you need them! 


5) Touch-ups: Let the paper dry for a day or two, then take a flashlight to check for any edges or seams that dried out and curled up. Using a small craft paintbrush and a few spoonfuls of wallpaper adhesive, wiggle a generous amount of glue under any loose edges. Wipe smooth with a clean damp rag. Curling, peeling edges may be more prevalent on south-facing walls, which expand and contract more. If you find any bubbles in the middle of your walls, carefully lance them with a box cutter, apply more glue, and smooth them out with a clean damp rag.

My north-facing walls look perfect! No touch-ups needed.

My south-facing walls had a few curling, dried-out edges. Easily remedied by adding more glue!

The pre-pasted paper adhesive was okay, but not as strong as the Roman glue I used for touch-ups, so if I were to do this again, I'd buy unpasted paper and glue it all with Roman. 

6) Painting: Woohoo! The fun part! Prime and paint your walls as normal. The white paper will expand again from the paint's moisture but will shrink back to normal and dry smooth, so leave these bubbles alone.


Look at these smooth, beautiful walls!!

The same spot, before and after.


If any seams dry and settle with a noticeable gap, you can fill the gap with drywall mud, smooth it out with a damp rag or sponge, then prime and paint. 

Small holes can also be repaired with drywall mud or tiny bits of caulk. Smooth it out with a damp sponge (don't sand!), then prime and paint the spot. I screwed up the measurements for my curtain rods, but the errant holes were an easy fix.

Mud patch before wet sponge-ing.

I decided on the color "Navajo Sand" (originally by Glidden but I got the sample matched in Valspar) for the whole interior and used a 1/2" textured roller to help hide any remaining imperfections. Navajo Sand is a beautiful beige that is so calming and gentle to look at, but more modern than tacky 80s puke-beige. Navajo Sand goes with everything and I LOVE, LOVE, LOVE it. The entire ceiling also got a fresh coat of white paint. 

Beige: The color of my soul.

Click to enlarge this photo. Blogger won't let me enlarge it for some reason.

Those blue lines are not decorative, people. They are measurements for curtain rods.

6) Replace trim, switch plates, curtains, etc. My next steps are to install baseboards and quarter-round trim around the ceiling/wall junctions, then trim out all the doors and windows. 

And that's it, kids! That is how to create padded walls. 

It looks great. But did it work?

You guys, it totally worked. 

My walls look nice and smooth, my trailer is quiet and comfortable, and my "touch the siding" test proves the heat and AC don't radiate straight through the walls anymore. I can keep the inside at whatever temp I want--warm and cozy in the winter, dry and cool in the summer. I'm much, much more comfortable day-to-day, and according to my electric bill, I'm using the same kilowatts per month for vastly increased comfort. I don't math good, but I think that means it's more efficient...?

What about those single-pane windows though?

Replacing 12 windows would cost several thousand dollars, and the window cranks prevent the use of inserts. Instead I bought full-length Sun Zero Energy Saving Blackout drapes and hemmed them with Stitch Witch to fit. Actually, I bought these insulating drapes first, then matched the wall color to them, and that's how I ended up with Navajo Sand. Not only do these drapes help insulate the thin windows, but they also discourage gnats and tiny moths from buzzing around my windows at night and finding their way in:

Sun Zero insulating drapes, before and after. Dark windows are less sexy to moths.

The total cost of the foam, paintable paper, glue, primer, and paint was $456.54. This project was quick, easy, relatively clean, lightweight, and cost me just one week of delivery tips. All the supplies easily fit in my car, I didn't need any help lifting or transporting anything, and I got the whole house done myself in about eight evenings.    

According to current prices for drywall, stud lumber, mud, and renting a truck to haul it all home, building new walls would have cost $494.64. Plus exponentially more time and mess, and ideally someone to help me carry 16 sheets of drywall.

Of course, like anything, there are a few cons. The foil side of the foam means you can't use a typical magnetic studfinder to hang things. But people with plaster and lathe walls also have that problem, so studs can be found in several other ways. For me, I can measure the seams of my exterior siding, then mirror the measurements inside. But really, how often do you have to find studs? 

The only other downside I can think of is when I had covid last December, I used a humidifier to help me sleep, and each morning my bedroom wallpaper would be bubbly. I'd turn off the humidifier, let in some fresh air, and the wallpaper would go back to normal. But I live in the desert, so I really don't know if this project would work in a very humid climate like Hawaii, the Carolinas, or Florida. It might look bubbly all the time. I don't know. You'd have to try it on a small section and see.

Wallrock advertises a lot about its fire resistance, and I'm not sure if my insulating wallpaper invention is fire resistant. I'd have to put together a sample and test it, but I don't think it would be worse than drywall because of the foam's foil backing; the paper is glued to metal, really. I'm not sure fire resistance is relevant to trailers or tiny homes anyway because they're so small, light, delicate, and open-concept to begin with. They're built to be kindling, unlike large brick houses with fire doors on multiple floors that can be shut to contain a fire long enough for a family of eight to escape. Regardless of your home type, keep a fire extinguisher or thick blankets on hand to smother small grease fires, keep the batteries in your fire alarms fresh, don't block your doors/windows with heavy furniture, be very careful with space heaters, get any strange electrical issues fixed immediately, clean out your dryer vents, and if your house is on fire, get the fuck out. That's all I have to say.  

That said, I conclude that my insulating wallpaper invention was a success. In February 2018, this 60-year-old trailer was cold, damp, noisy, and full of bugs and lizards. Now it's warm, clean, quiet, dry, and comfy. It worked for me, and it may work for your shed, boat, sunroom, RV, trailer, tiny home, storage space, or whatever. Naturally, don't take my word as gospel. I'm not a guru, architect, or engineer. Do your own research, understand your space's envelope, and make your own informed decisions. I'm not responsible if you try this and somehow manage to blow up your entire trailer park. I'm a pizza delivery driver who glued foam and wallpaper to the walls of my cheap little trailer. That's it.  

But someday I'll live in a normal house with standard framing and decent insulation and a real HVAC system, but in the meantime, this place is kinda cute with the padded walls. Perfect for hanging straight jackets...

Oh, and stay tuned for The Great Kitchen Reveal! Here's a teaser photo: