Interior Walls and Ceiling Material Ideas Needed

ExpoMike

Well-known member
Hi all,

I have finally fully gutted my M1010 ambulance and am getting ready to start building up the interior. The box is all aluminum using Z channel stud walls and roof, skinned in sheet aluminum. I am planning to use XPS (if I can find locally, which I am having a hard time of) or EPS foam board to insulate the box. I am trying to eliminate or use very little wood inside, to prevent any issues with possible water damage or rot down the road. Originally the inside was skinned in embossed aluminum sheet, riveted to the studs. This method would definitely have issues with thermal bridging which I would like to eliminate as well.

My original idea was to use FRP panels attached to the studs using 3M VHB tape but after talking to a FRP company about my use, they couldn't recommend it for overhead use, let alone not being glued to a solid subsurface. Not sure if this is a viable option at this point. Nice thing about this option was I could get 9' long panels, so I could run them full length front to rear, to minimize joints. Cost was looking around $550 shipped. Concern is, without any subsurface to be glued to, the FRP panels would sag between studs overhead. Another plus is I can get them in some colors outside of basic white.

Then reading in another ExPo member's thread, they used ABS sheets. I went by and talked to a guy at E-Plastics (where they got their panels). Seems like a viable option as he indicated they are very thermal stable and would not need a subsurface to attach to (looking at the 3/16" thick panels). Downside is the weight at 33 lbs per panel, which in a overhead use, I don't think VHB tape would hold long term, requiring some mechanical fashioner, likely creating a thermal bridge. Other items to note, they only come in black or white colors, they are only available in 8' lengths, requiring me to run them vertically so the long walls and ceiling would have 3 joints versus 1 of the FRP panels. Other factor is cost is $1100, double the price.

My question for everyone are as follows,

1. Am I overreacting to the use of wood panels and/or is there a good way to waterproof them?
2. Are there other options beyond wood, FRP or ABS panels that would hold up to camper use (heat, moisture, vibration, etc.) and would work for overhead use by attaching to studs only?
3. Are there better methods to attach panels to the studs, to not cause thermal bridging but will hold up to this use?

One thing to note, weight is a concern as is thickness. With such a limited space, I do not want to use up any extra space then absolutely needed.

Throw out some ideas, thoughts, comments or suggestions. For reference, this is what the inside looks like.

0327211248_HDR.jpg

1128201236.jpg
 

bahndo

Supporting Sponsor: Bahn Camper Works
You can use coosa panels and either upholster or apply a solid surface laminate for your finished walls. Bond them to the studs with either a mma adhesive or 3M 5200. You could even skin them with a wood veneer if you like that look more, I would recommend a 3/8" or 1/2" panel thickness.

Sent from my S61 using Tapatalk
 

ExpoMike

Well-known member
You can use coosa panels and either upholster or apply a solid surface laminate for your finished walls. Bond them to the studs with either a mma adhesive or 3M 5200. You could even skin them with a wood veneer if you like that look more, I would recommend a 3/8" or 1/2" panel thickness.

Sent from my S61 using Tapatalk
That is some interesting stuff. Very cool but well beyond my price point.
 

4xchinook4

Observer
Just talking out loud . Don't know too much bout it. But maybe Cedar wood. Being naturally resistant to mold and what not. As far as wood goes its tongue and groove panels can be pretty light weight at 8' and ¼" thick.

Obviously not the lightest option. But its an idea

Not to mention smells good. Haha

Sent from my SM-G960U using Tapatalk
 
You may be overreacting about the wood issue. 3/16 or even 1/8 luan is light, even with a textile like marine carpet glued on the interior side. Perhaps a deck paint on the frame side for ease of mind? I’ve considered using the luan with thin indoor/outdoor ribbed carpet so that any inside condensation doesn’t create a rainforest...all easily obtained at Lowe’s or HD. Good luck with the build.
 

Roaddude

Long time off-grid vanlife adventurist
I've used regular white tileboard in a couple vans with great success. Inexpensive, light, attaches easily with self-tapping screws through white-capped washers (no idea what their real name is) that hide the screw heads for a finished button look. You can see two rows in the ceiling and a few on the walls in the images below. Surprisingly few hold up a whole sheet. No adhesive or VHB.

The tileboard is a masonite with a smooth white semi-gloss finish on one side. $13.50 a sheet right now at the big box stores and only 1/4" thick at most. The 1st image below, when I used the van for hauling cargo all over North America, gives the best view.

I have XPS in the ceiling, simply arched into place and taped with reflectix tape to seal, then the white tileboard over held in place by only screws into the roof beams; no adhesive or VHB on the insulation or tileboard. No wood strips for screwing to. Not even screwed along the long sides, as I was planning on putting in upper cabinets.

In the walls, as an experiment, I first installed only Reflectix between the metal wall pillars, suspended from the outside skin of the van by spacers half the depth of the pillars; taped completely with Reflectix tape as seal to prevent any heat migration; then the white tileboard screwed directly to the pillars, leaving an equal space between tileboard and reflectix. From the outside in: van skin, air space, reflectix, air space, tileboard.

Again no loss of space to 1x wood strips on the wall for screwing. Reflectix, grossly misused by most, when glued directly to the outer skin acts as a conductor, not a reflector. When suspended, leaving air gap from both outer skin and inside wall as it is supposed to be, it is shockingly effective. It reflects the heat back out in summer and keeps the heat inside in winter.

It worked so well as an experiment, I left it as is, with no other insulation in the walls since I put it in almost ten years ago. I've slept and lived in it like that from northern Quebec to the Chihuahuan Desert in all seasons and have never regretted it.

One thing I like about the tileboard--other than being very inexpensive, is that you can get white moulding strips to finish both edge and joints between pieces, whether butt-jointed or right angle, as you can see on the ceiling about two-thirds the way back, and in the corner of the wall to 1/4 bulkhead (missing from the 3rd image). The ceiling has one full 8' sheet of tileboard and another half sheet at the far end, joined by a plastic moulding strip going side to side.

Driver's side wall is one horizontal 4x8 sheet 'til about 15-18" this side of the 1/4 bulkhead. Hard to tell, but there is a joint with a white double u strip. Easy to use, no glue, looks good. I didn't bother with tileboard below 4' from the ceiling on either wall, as the side cupboards hide those few inches that aren't sheeted.

Other things I like: it is super easy to clean, though rarely needs it; does not absorb smells like wood or a carpeted wall (a big deal in a small living space), and reflects light better than a dark interior of wood or carpet. I often use only one of my Ready Light pods for interior light (seen at the top edge of the last image).

Tileboard is also very easy to replace if needed, though I've never had to yet. After ten years, though, it is finally starting to look dinged up from my bike, throwing gear in there, and stuff banging around. All getting replaced this year, as I redo the whole interior in prep for cabinets and potential poptop. I'm going to use tileboard again. There's maybe 5 sheets of tileboard = $65.00 at current prices to do the whole van.

The 1st image was five or six years ago and the tile board was several years old already. The 2nd image was in 2012, not long after it was put in. The third image is summer 2018. Last image is late summer 2019.

Absolutely no problems with thermal bridging (I think that's where you're overthinking) from the few fasteners used and no sagging or letting go in the ceiling panels other than at the long edges, which were never fastened, taped, or glued. A flat ceiling may be different as the arch in mine--even so slight--helps keep the shape over the length. Though I'm confident that a few nice rows of fasteners would keep it flat on your ceiling. Never had a problem with mine being dimensionally unstable due to temp swings. Never had a leak, so can't speak to problems from that.

cargo_2802-900.jpeg
Walls and ceiling both have the same tileboard.
..

ChisoMtns2012_1359.jpg
2012
..

vanint_6042-900.jpg
2018 - missing the corner strip at the half bulkhead after moving it.
..

vaninterior-181127_7050-900.jpg
Late summer, 2019

It's held up well for years. I don't like all white walls in a house, but in my van it's perfect.

.
 
Last edited:

dbhost

Active member
Just talking out loud . Don't know too much bout it. But maybe Cedar wood. Being naturally resistant to mold and what not. As far as wood goes its tongue and groove panels can be pretty light weight at 8' and ¼" thick.

Obviously not the lightest option. But its an idea

Not to mention smells good. Haha

Sent from my SM-G960U using Tapatalk
I was going to suggest Cedar as well as it is widely used in marine installations with no issues. 3/16" shiplap is readily available, at least near me it is, at pretty decent prices, it smells great, and has the added benefit of repelling insects and other pests.

Cedar is incredibly light as well so it would help keep weight in check.
 

BritKLR

Kapitis Indagatoris
Not a van but, when I redid the interior of our Tiger I used Birch 1/8 inch paneling and birch solids for the cabinets. It's held up very nicely for the past 4-5 years, plus when it gets dinged or scratched I just wipe it with some wood oil and it blends right back in. The bathroom got regular white shower surround pvc glued to the subframe board. Goodluck!

2F82339A-82AD-4CA7-848C-78D84CDAB880.jpegADA5C15B-BE48-47E0-A50D-B3E8944B5CAE.jpegA48FB5CD-4662-4A82-B279-A7C56F5A2C22.jpegECD9E9CB-67D4-4F3E-B479-94BD2B1B640C.jpeg11A7D9E0-E732-4A07-828A-6FEFC4194998.jpeg55B03E54-AEF9-4DBB-AE3E-9385D9C71D82.jpeg
 

BritKLR

Kapitis Indagatoris
Forgot to mention about ABS plastic sheeting. If you have a plastic supply company where you live check and see what colors they can get 4x8 sheets of textured ABS plastic in. It's easy to cut with a jigsaw and bend with a heat gun. It's 1/8 thick and super strong. Back when I did the interior panels of my Land Cruiser in black they offered the 4x8 sheets in the colors of the rainbow. Good luck!
2BDA3F91-BE66-476F-B0CD-CD95B12BF554.jpegEF2AD288-CFD5-4C06-BF5B-1915885D6C90.jpegE0A4F85A-EE93-4FB7-B257-61BB131722BE.jpeg96EBB6F3-94AA-4D07-A319-AF1874D5DF28.jpeg60DACA19-7D56-4319-921F-0B39DC4CBE24.jpeg
 

ExpoMike

Well-known member
Thanks everyone with info so far.

@Roaddude Interesting. Thanks for the real world use and longevity you have been seeing. That might ended up being a good option. Definitely cost effective.

@BritKLR If you look in my original post, I already talked with a local supplier of ABS and got a quote for over $1100. I did ask about colors an actually colored ABS is not common, as I did a bunch of research on this. You can find colors but they are actually for laminate use (.040 thick). I can even get that pre laminated to 1/4" Luan ply. To get 1/8" and thicker, you're basically limited to black or white, unless you custom order colors but then there is a huge minimum purchase for that. As for the Birch, looking at your pics (nice Tiger BTW), it seems you have some warped panels up near the top of the cabinets. This is the type of issues I want to avoid.
 

BritKLR

Kapitis Indagatoris
Thanks everyone with info so far.

@Roaddude Interesting. Thanks for the real world use and longevity you have been seeing. That might ended up being a good option. Definitely cost effective.

@BritKLR If you look in my original post, I already talked with a local supplier of ABS and got a quote for over $1100. I did ask about colors an actually colored ABS is not common, as I did a bunch of research on this. You can find colors but they are actually for laminate use (.040 thick). I can even get that pre laminated to 1/4" Luan ply. To get 1/8" and thicker, you're basically limited to black or white, unless you custom order colors but then there is a huge minimum purchase for that. As for the Birch, looking at your pics (nice Tiger BTW), it seems you have some warped panels up near the top of the cabinets. This is the type of issues I want to avoid.
I missed that. My apologizes.

The gaps (warped) that your seeing is actually the contours of the fiberglass roof that the ceiling panels are mounted too. All Tiger ceilings have this gap and actually have trim molding between the ceiling and the cabinets to hide and dress up the fit since the top of the cabinets aren't cad cut to the contour of the ceiling. The pictures were taken before I added the final trim molding, but once added you no longer see the gap. Goodluck with your project.
 

ExpoMike

Well-known member
I missed that. My apologizes.

The gaps (warped) that your seeing is actually the contours of the fiberglass roof that the ceiling panels are mounted too. All Tiger ceilings have this gap and actually have trim molding between the ceiling and the cabinets to hide and dress up the fit since the top of the cabinets aren't cad cut to the contour of the ceiling. The pictures were taken before I added the final trim molding, but once added you no longer see the gap. Goodluck with your project.
Thanks for the clarification on that. No worries about the ABS. :)
 

dstefan

Active member
2. Are there other options beyond wood, FRP or ABS panels that would hold up to camper use (heat, moisture, vibration, etc.) and would work for overhead use by attaching to studs only?
3. Are there better methods to attach panels to the studs, to not cause thermal bridging but will hold up to this use?
I’m a big fan of coroplast, a.k.a. plastic cardboard. it’s lightweight, cheap (you can buy white sheets at Home Depot for about 20 bucks for a 4 x 8‘ sheet), slightly insulating by virtue of having hollow channels and air space, very tough and durable, but flexible. You can heat bend it, it’s easy to cut with a utility knife or a channel cutter made specifically for it. You can split one side along a channel and leave one side intact and make radius bands with it as well. You can even hide wiring in the channels (probably no more than 18 to 16 gauge). Comes in many colors and even with a grey fabric facing. I’ve been prepping it with alcohol and light sanding and VHBing Velcro to and it holds really well.

I just did the inside of my pop-up shell with quarter inch closed cell foam sandwiched between radiant barrier for insulation and chloroplast to cover. It’s all put up with VHB. worked great over a 1 week, 150 miles of washboad roads trip.
 
Top