Insulation

[Twigg]

Originally Posted by gzimmerman372

Is the R-Max (or any other foil backed) worth doing? Is there enough benefit? I will be full-timing and going to rather cold and hot climates periodically.

I was set on using polyiso (R-Max) until I did some careful reading.

Polyiso has the highest R-Value per inch (6). Next best id XPS (the pink stuff 5).

However, it turns out that those ratings only apply at the standard test temp. of 70 or 75F. As the temperature falls the polyiso R-Value falls too, right down to 2 when it gets really cold, whereas the R-Value of XPS actually rises slightly.

Don't worry too much about compressive strength. Polyiso is available with a strength right up to 40 psi.

I used the XPS. It's strength is 15 psi, and with 5/8" plywood on top it is perfectly fine.

[gzimmerman372]

Great information from everyone. So I think I'm going to do foam board, not foil backed, all around. The ribs at 2" tall so I've got that much space to work with for insulation. Should I do 2x 1" board, 1x 1.5" board or 1x 2" board? It will be glued to the exterior skin (steel floor, wall, or roof) and then a plywood subfloor, wall or some flexible type wood for the ceiling.

This forum is a great resource, I hope I'm not overdoing by asking too simple of questions.

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[gzimmerman372]

Originally Posted by TrailLifeBill

I am furring out my ceiling with 1x3's over my steel frame, with rubber window tape in between the steel and wood. Then I am going to cut 1" foam board and gluing it to the outside skin, followed by spray foam to get the nooks/crannies that were missed. The ceiling will be tongue and groove boards screwed into the wooden furring strips. Walls will be similarly done, but will be FRP panels attached to the wooden furring strips.

The plan of what you are actually doing, that seems to me like it's leaving roughly 1.5-2" air pocket between the 1" foam board and the T&G ceiling or FRP walls, is that right? Why not fill that with another layer of the 1" board and leave .5-1" air pocket, or even triple layer to have no air pocket?

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[Twigg]

Originally Posted by gzimmerman372

Great information from everyone. So I think I'm going to do foam board, not foil backed, all around. The ribs at 2" tall so I've got that much space to work with for insulation. Should I do 2x 1" board, 1x 1.5" board or 1x 2" board? It will be glued to the exterior skin (steel floor, wall, or roof) and then a plywood subfloor, wall or some flexible type wood for the ceiling.

This forum is a great resource, I hope I'm not overdoing by asking too simple of questions.

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You probably won't get 2" board behind the chair rail.

[TrailLifeBill]

Originally Posted by gzimmerman372

The plan of what you are actually doing, that seems to me like it's leaving roughly 1.5-2" air pocket between the 1" foam board and the T&G ceiling or FRP walls, is that right? Why not fill that with another layer of the 1" board and leave .5-1" air pocket, or even triple layer to have no air pocket?

Not quite there yet, but yes - since I'm spraying, the area will be filled with either another layer of board or spray over board. Will mock up a trial area and see what works best. Same with walls. So far I just have decided on the concept, but the details will iron themselves out in implementation.

[gzimmerman372]

For the floor....

Recommended to do an underlayment layer like the ice/water shield that is self adhesive then small wood frame and foam board/subfloor and all...or...no underlayment and just the foam board straight in the steel?


Steel will be coating with a rust converter and primed before the next layer, but which direction should I go?

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[Twigg]

Originally Posted by gzimmerman372

For the floor....

Recommended to do an underlayment layer like the ice/water shield that is self adhesive then small wood frame and foam board/subfloor and all...or...no underlayment and just the foam board straight in the steel?


Steel will be coating with a rust converter and primed before the next layer, but which direction should I go?

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Once the floor is sealed and primed, the foam board can go straight on top.

No benefit is adding layers, barriers, etc, just keep it simple.

Steel, insulation, plywood, final flooring.

[B-ryanm]

Originally Posted by Ljmbw357

Can someone let me who would insure the bus in Florida

I ensured a 96 T444E threw progressive. Got it ensured as an RV. It’s kinda tricky. You can never say it’s a school bus or has ever been a school bus since you have come to own it. That it’s your camper/rv project.(which in my case it is) The least you say the better. If all goes well you’ll get yourself a cheaply ensured Schoolie.
Hope this helps.
B-Ry