Need help selecting ceiling insulation materials

[TheStinker]

Hey. I'm new here. My partner and I are currently converting an E-450 based shuttle bus and I'm hung up about what to insulate my ceiling with. I've dug extensively through the the forum but haven't exactly found what I need.

My ceiling is gutted and whats exposed is a thin layer of steel(?) and the steel ribs. The outer shell is fiberglass. I've figured on using 1/8" or 1/4" luan for the ceiling.

What i can't figure is what to put between the ribs. I've seen foam blocks (which is what was originally up there) and I've heard people talking about expanding foam insulation like great stuff. I know great stuff can't be used in a enclosed space so would one have to put it up and then shave it down before putting up the boards? Is this any easier or cheaper or more effective than using styrofoam blocks? Is there a third thing I'm completely missing? I a reflectix layer a good idea?

Any help is greatly appreciated.

[DreamWeaverBus]

Inexperienced opinion here: All those sound like good ideas, at least as far as my research has led me to believe. Spray foam seems to be king if you can afford it, otherwise it seems like rigid foam boards, spray foam in between to seal, and reflectix seems like the next best.

I plan to do just that: spray foam if I can afford it, otherwise rigid foam with spray foam to seal, and reflectix. Some more experienced people should chime in soon..

[Robin97396]

Aside from the spray foam and rigid insulation is the newer rockwool. Some are using that in their builds currently.

The long term thought is that you can use a thin coat of spray foam to insulate the outer skin and ribs 1/2" deep, eliminating condensation while also sealing the interior. Use any other type of insulation, or more foam, to fill in to whatever depth you feel you need. Some have six inch thick walls and ceilings, usually involving several types of insulation. It's all about how you intend to use your bus.

I have spray foam filling the walls and ceilings to rib level. Beyond that I put up 1/2" rigid insulation before putting in a durable interior surface of plywood. I've also retained all my windows, which isn't good during cold weather, so I've cut panels of insulation that cover one or more window frames. I estimate a 70% reduction in heating energy this winter, which was a unusually hard winter this year. I don't have experience with other types of insulation so it's hard to make a comparitive conclusion.

[DreamWeaverBus]

How thick are most bus ribs? I was thinking of spray foam up to that thickness then other insulation outside that. Can you get spray foam less than the thickness of the ribs so the extra insulation you get doesn't go past the ribs? Or is it hard to gauge when spraying? I guess ideally it would be good to get spray foam up to ribs then other insulation beyond that to increase r value.

[Robin97396]

I'm having some issues with R-values. The 1/2" rigid styrofoam insulation I use against the windows has an R-value of just under 2. Yet it works very well in freezing temperatures, as well as stopping the sun on hot days. Doesn't make sense.

[DreamWeaverBus]

I remember you talking about that somewhere... Weird huh? Maybe we don't need as much R value as we think. I'd still rather over do it than under do it.

[Robin97396]

It just makes me think. Has anyone done only the 1/2" of spray foam? I honestly don't know how spray foam compares to styrofoam in R-value but it seems they'd be similar. Rigid styrofoam flat against a window works well in the winter, so I'm wondering if 1/2" of spray foam would possibly be adequate in that same sense that the styrofoam seems to work. Maybe I'll try that on my next bus.

[DreamWeaverBus]

Honestly it's making me thinking that spray foam might be overkill for the price and R value. It just keeps coming back to an effective vapor barrier...

[CaptSquid]

I've installed 1" rigid insulation on the sides, with removable panels for the door and windshield. Remember, though, you'll lose/gain more heat through the roof. This 1" gives me an R-6 on the sides. I haven't insulated the overhead (yet), but I've already done TWO Montana winters in Brunhilde. I use catalytic heaters to keep the cold down to a manageable level.

[Shambhala Tinbolle]

Originally Posted by TheStinker

Hey. I'm new here. My partner and I are currently converting an E-450 based shuttle bus and I'm hung up about what to insulate my ceiling with. I've dug extensively through the the forum but haven't exactly found what I need.

My ceiling is gutted and whats exposed is a thin layer of steel(?) and the steel ribs. The outer shell is fiberglass. I've figured on using 1/8" or 1/4" luan for the ceiling.

What i can't figure is what to put between the ribs. I've seen foam blocks (which is what was originally up there) and I've heard people talking about expanding foam insulation like great stuff. I know great stuff can't be used in a enclosed space so would one have to put it up and then shave it down before putting up the boards? Is this any easier or cheaper or more effective than using styrofoam blocks? Is there a third thing I'm completely missing? I a reflectix layer a good idea?

Any help is greatly appreciated.

hello, i'm the inexperienced voice on this thread.
I'm in planning/research stages of my adventure - bus purchase is in process.
Though spray foam insulation(s) is wildly popular, I don't want it in my bus home. That's a personal choice because of health.
I have been looking into radiant foil and specific insulating of 'metal buildings'.
I see my bus as a building on wheels that happens to be made of pretty serious metal, so figure that insulation geared to metal buildings would be suitable.
https://www.radiantguard.com/pages/h...ls%20&%20roofs
This link may be of help in your query.
Idea I have is to strap & insulate exterior, then sheath with wood or metal. Then do another process for the interior - vapor barrier, strap, insulate, sheath. I don't know what 'R' value this approach would give, or what challenges will present themselves. Like with many insulation approaches, the answers lie miles and years down the road...
very best to you,

[DreamWeaverBus]

Originally Posted by Shambhala Tinbolle

https://www.radiantguard.com/pages/h...ls%20&%20roofs
This link may be of help in your query.
Idea I have is to strap & insulate exterior, then sheath with wood or metal. Then do another process for the interior - vapor barrier, strap, insulate, sheath. I don't know what 'R' value this approach would give, or what challenges will present themselves. Like with many insulation approaches, the answers lie miles and years down the road...
very best to you,[/FONT][/SIZE]

I like your thinking!! As Robin has said, I am chasing my tail over and over on this insulation business. Cost IS a big factor with me, but doing the thing RIGHT is also big, since I plan on moving north and want to not freeze my ass off. But also not OVER doing it is big, if something cheaper and easier can be done, I'd like to do that. Reflectix type stuff is high on my list right now. I'm gonna just keep chasing my tail prolly. Once I have a bus and gut it and get a quote from local spray foam people, then I'll be able to make a choice. Your link was very helpful, thank you!!!

[heeranyi]

When you say spray foam is expensive, how expensive are you talking about?

[DreamWeaverBus]

Most of what I have read says one DIY home kit of spray foam will cost $500-$600, like this one on eBay: Touch 'n Seal U2-600 Spray Foam Insulation Kit Closed Cell-Standard FR - 600BF | eBay
That gives you 600BF, which means one inch of thickness on 600 square feet of surface. (Correct me if I'm wrong, peeps) You'd probably want at least 2 for a decent job on a school bus, so that's about a thousand dollars right there DIY. In my area, midwest, I can probably expect to pay double that for a pro to do it. If I do it at all, to save money I'm probably gonna DIY.

[EastCoastCB]

The professional spray foam guys here don't even return calls or emails about spraying a bus. The quotes I have managed to get were over two grand.
I'll DIY. Better off doin it myself anyhow.

[superdave]

Originally Posted by DreamWeaverBus

Most of what I have read says one DIY home kit of spray foam will cost $500-$600, like this one on eBay: Touch 'n Seal U2-600 Spray Foam Insulation Kit Closed Cell-Standard FR - 600BF | eBay
That gives you 600BF, which means one inch of thickness on 600 square feet of surface. (Correct me if I'm wrong, peeps) You'd probably want at least 2 for a decent job on a school bus, so that's about a thousand dollars right there DIY. In my area, midwest, I can probably expect to pay double that for a pro to do it. If I do it at all, to save money I'm probably gonna DIY.

good kits, covered my 32' bus with 2"

[heeranyi]

Thank you for the info. I guess if it saves me and my little ones from being hot or cold for years to come, it's worth paying for. Ok, I guess I'll be watching some videos on how to diy spray foam.

[Robin97396]

You ought to see the look on the commercial foam sprayer's face when I started talking about spraying foam under the floor. Not a happy look.

[heeranyi]

oh my goodness, I can only imagine. Maybe a halloween mask with goggles. lol

[TheStinker]

Sorry for the long wait responding. For those interested, i ended up using 2" thick extruded polystyrene (xps). I cut it carefully so that it would wedge between the ribs of the bus with three pieces per rib section to adjust for curve. I filled in all the gaps with great stuff and shaved it down. Then I painted and cut to fit some 11/32" plywood and screwed it up on the ribs. Seems like it will do the trick.

Thanks for your input! Now on to the next problem.

[Tango]

Sounds good...but without pix...it didn't happen. Jack's rule.