Wall insulation questions

[FatBoySTL]

I'm about ready to put insulation in the walls. I'm going with 2" polyiso foamboard with an aluminum backer. Questions for those who've done foam board in the walls:

Did you trim down the rub-rail screw tips before putting the foam in, or just press the foam over the screws?

Did you glue the foam to the outside wall? Glue the inside panel to the foam?

Did you fill all the gaps with spray foam from a can? Lots of caulk? Tape the seams?

Did you do anything specific to avoid squeaks while running down the road? Did it work? What would you do differently?

Thanks a million!

[Drew Bru]

We used 3" blue foam. I don't think we used adhesive, we just cut the sections so they'd press in firmly. I don't remember whether there were protruding screws, but if there were I'm sure we just pushed the insulation into them. We shoved 1 1/2" (?) insulation behind the chair rail, then put some over the front to be flush with the blue foam. We taped all of the seams, but didn't use spay foam. I think we may have shoved insulation scraps into any cracks or crevices. We then sheeted over it with 1/4" luan plywood and used adhesive to hold it to the insulation, and self-tappers to attach it to the ribs. We put beadboard over the plywood.
The walls were wavy in places but it doesn't show up in a finished bus full of cabinets and furniture. We've never had any problems with squeaky walls, so that may just be an urban legend.

[ol trunt]

I used two 1" layers of foam everywhere and 3" in the "cab". I stuck the layers together with spray glue compatible with foam to hold things in place long enough to get the interior panels back on. I used spray foam to fill voids in the sheet insulation. Happily I have no squeaks from the foam insulation.
Jack

[Danjo]

Originally Posted by ol trunt

I used two 1" layers of foam everywhere and 3" in the "cab". I stuck the layers together with spray glue compatible with foam to hold things in place long enough to get the interior panels back on. I used spray foam to fill voids in the sheet insulation. Happily I have no squeaks from the foam insulation.
Jack

Didn’t think of squeaky foam. You don’t want any Squeaky Fromme either, BTW

[FatBoySTL]

Originally Posted by Danjo

Didn’t think of squeaky foam. You don’t want any Squeaky Fromme either, BTW

She's harmless now... Gotta be an octegenarian by now, right?

Ok, one last question (I think): This is a 4-window bus. Between the kitchenette, dinette, cabinetry, bed, and shower, ALL of my walls will be covered (at least to the window sill) with cabinets or permanently mounted furniture. ALL furniture will be mounted to the plywood floor and chair rail, with the top of the waist-high cabinets also getting screwed to ribs just below the window. I don't need wall board thick enough to anchor anything, and I don't need anything cosmetic (it won't be seen unless you're pulling at the in the back of a cabinet).I just need something thick just need something on the walls thick enough to hold the foam in. I was considering using plastic wall panel boards... They're very thin and completely water-proof. I can glue them tight to the foam, then screws into the furring strips or ribs. Thoughts?

Thanks again!

[SpaceWaster503]

I also have a short 4 window bus and am wondering about spray insulation vs. cutting squares of "foam board" insulation??
Advice??

[Danjo]

Originally Posted by FatBoySTL

She's harmless now... Gotta be an octegenarian by now, right?

Ok, one last question (I think): This is a 4-window bus. Between the kitchenette, dinette, cabinetry, bed, and shower, ALL of my walls will be covered (at least to the window sill) with cabinets or permanently mounted furniture. ALL furniture will be mounted to the plywood floor and chair rail, with the top of the waist-high cabinets also getting screwed to ribs just below the window. I don't need wall board thick enough to anchor anything, and I don't need anything cosmetic (it won't be seen unless you're pulling at the in the back of a cabinet).I just need something thick just need something on the walls thick enough to hold the foam in. I was considering using plastic wall panel boards... They're very thin and completely water-proof. I can glue them tight to the foam, then screws into the furring strips or ribs. Thoughts?

Thanks again!

FRP? Sure that would work

[FatBoySTL]

Originally Posted by SpaceWaster503

I also have a short 4 window bus and am wondering about spray insulation vs. cutting squares of "foam board" insulation??
Advice??

I would love to have a pro spray in foam throughout, but that's $600+ (minimum job size). I can buy a kit and do it myself for $400, but that's still out of my budget, and I'd probably screw it up (in hilarious and disastrous ways). Using 1.5" foam boards, I can do the floor and walls for under $150 (not doing ceiling at this time). The polyiso actually has a higher R-value per inch than spray foam, but the spray gets into every nook and cranny, so it's probably a wash.