Original Insulation . . . how impotant to replace?

[bamudd]

So, how important is it to tear out the walls and ceiling and replace the original insulation, assuming that all of the above are otherwise in good condition? Will the original soft foam insulation work, or is it really imperative to tear them out?

[kflowers]

I have been wondering the same thing. I have recently taken some panels of my bus. The biggest problem I have seen is the fiberglass on my bus has settled about 6 inches. There are also a couple sections of insulation that water got on them that need to be replaced. I am taking all the panels off my bus to raise the roof.

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[AlleyCat67]

The original insulation is ok for a vehicle but if you plan on living in it, even on a part-time basis, you will want much more/better insulation. There are much better insulation options out there so in a nutshell yes you need to pull that insulation.... if it is in decent condition you can reuse it if you like but add more to it. But consider that you can get a higher R value in the same thickness if you look around.

[bamudd]

What is the R value of that kind of foam?

[bamudd]

And what's the belt insulation to put in a space that thin? Only like a 3" gap on the walls and 2" on the ceiling . . .

[Dapplecreek]

Originally Posted by bamudd

And what's the best insulation to put in a space that thin? Only like a 3" gap on the walls and 2" on the ceiling . . .

Others will reply with more detail, but the short answer is 'professionally sprayed closed cell foam'. (You can do it yourself for $600 a kit but you're likely to need two or three kits by the time you learn how, so it is cheaper to do ALL of the prep work yourself then drive your bus to where the guy is working so he doesn't have to set up/tear down for a trip to your place.)

[bamudd]

How much is that likely to cost?

[AlleyCat67]

Originally Posted by bamudd

How much is that likely to cost?

From what I've heard, having a pro do it will cost less than it will to do it yourself because the professional won't have nearly as much material waste as a DIY job, what with the learning curve and all. YMMV.

[bamudd]

Good to know. Do you know about how much that would be though?

[AlleyCat67]

Unfortunately I do not, I'm not to that point in my conversion yet. 3 kits would be 1800 plus tax, so you can use that as a baseline of sorts.... where in the country you're located will also factor into that.

[Geo Jeff]

The small round vents in the roof at the front and back of my bus ceiling. What or how do they work. I assume they direct vent some how? Trying to decide if I need them or not for moisture control.

I'm taking some rivets out right now from the ceiling and just removed the corner or transition panels from ceiling to wall. the had screws I assume because all the wiring is under them. I've ground on rivets drilled rivets out broken bits. my arms feel like there falling off. I'm curious who these people are that think cutting foam and insulating 1 to 3 of insulation is much different than this factory installed glass. As a cheaper and faster route what does any one think of having insulation just blown in through some holes like they do on the side of your house. I'm just looking at chasing 70f down but if it gets cold some where I don't mind running the heck out of heaters.
I guess what I'm wondering is this insulation idea from the cold states. The r value of the foam we would slice and put up there must be about the same as this home insulation we have. The only real way to get more than a couple R value here is spray foam at 6R a inch witch is amazing. But more for some one that isn't going to be in warmer weather.

Also I had this thought since I was wanting to reuse or leave my perforated roof panels in place. What about just having them foam through holes and let it squeeze through the metal paneling? or even drill hole for the bit of expansion?

These rivets are a ass kicking and it would sure be nice to be able to reuse them in my project.

I'm hoping planning? to just paint the ceiling white inside with rustoleum. And seal all the roof top seems with some type of caulk and then a roof sealer over that.

I see the good news bus has the original roof and they did not take it out. They had a cold issue I saw so in stalled a good forced air propane furnace and it looks like the problem was solved.

I just wonder if were trying to hard and were basing it on ideas not fact's. My roof seems to be insulated very well with no gaps? the foam board has a very low R value. Why are we switching. Then spray foam has aR18 value in a roof it looks like and that would be a good reason fro some people.

[AlleyCat67]

Pulling the ceiling panels and stripping out the old insulation also allows you to make sure you don't have a mold/mildew farm going between the outer and inner panels, which if the outer skin has leaks in it is a very real possibility.

Strictly speaking, no you don't HAVE to do that. But if you don't, and your outer roof does leak, it's just going to make an already existing problem worse. It will eventually rust through the inner sheet metal as well, and depending on where it comes through and what you have there then you could have real problems on your hands if it were to start dripping on your electric panel, for example.

The foam board insulation may not have much R value but from what others more knowledgeable than me have said about it, what's already up there isn't even as good as that. Fine for a vehicle going down the road or an occasional weekend camping trip, but not if you intend to live in it for any length of time.

Spray foam is very good in terms of R value but it's best applied after stripping the inner panels off.... you COULD cut holes and fill the cavity but my concern with that would be either causing rapid corrosion of BOTH inner and outer skin (which I've heard, from other threads here if memory serves, can and does happen under the right conditions), or that the expansion would cause one side or the other to bulge and maybe even pop off if it needs more expansion room than it has.

I've also read that the best way to deal with those rivets is with what I think is a flapper wheel, which is basically just a big floppy grinding disc. As I recall that also has an advantage in that it doesn't gouge up the panels so you could reuse them if you wanted to, though I'm not sure I personally would want to try to reinstall them (though I would hang onto them, they could be repurposed for other aspects of your build).

[Geo Jeff]

I hear what your sayi9ng but I'm not convinced. If some one has a leak they should fix it. This insulation installed in my roof is the R value as replacing it with that white Styrofoam Board. Its the same stuff you put in a 2 x4 wall its not like they made insulation for the bus. Sealing my roof with caulk and the roof coating is as good as it gets. If that cant keep a roof from leaking for 10 years I'm not sure any one has a chance. Plus the only leaks I can find on line seem to be from roof vents cut in. I'm not about to count rust that's just something you would fix or a accident and its fixed poorly. I don't have either.

I think its safe to say unless you have a leak you cant get more R value unless your spray foaming as its several times better than every thing out there. the real issue is stopping future leaks and there are so many amazing products from EPDM rubber roofs to latex style snow coats to the fiber roll on coatings for homes. We know there is caulking for pre sealing the roof that simply is amazing and almost becomes part of the roof itself.

I'm headed back out to the bus to re install some rivets. NOw the side panels under these shitty windows is a different story I can see how they could have stuff in there. its to bad they didn't seal these windows up at the factory but I appreciate how easy they come out today while I'm working.

Any one have 1 emergency exit with a fan there not using. Do you know if the fan can be added to a non fan set up or its it requires the whole vent.
I have with and one with out. The one with out is in my bathroom just by luck so I though a fan unit would be a perfect option for a shower fan for moisture or vent for my compost toilet.

[TAOLIK]

I was not able to get any direct quotes regarding spray foam contractors in Washington state because I couldn't find anyone to do it/I only tried for a day. But I get the feeling it is in the $1200-2500 range depending on how thick you want it.

I went with polyiso foam (2 inches in the walls, 2.5 in the ceiling, .5 xps in the floor). I have been insulating for a month now. I haven't kept track of my costs but it's projected to be somewhere around $1000-1200 give or take, I've probably spent too much money on reflectix though(I still love it though). It's taken me about 1-2 months and about 60-80 hours probably to insulate the bus and I'm still working on it. This time value of money alone is worth the extra dollars for the 2 part spray foam.

From what I understand you don't want to spray foam without having proper air to cure the foam, otherwise the uncured sprayfoam will corrode the crap out of your metal. If you're going to spend thousands of dollars on your bus conversion, you really shouldn't half ass or gamble with "it will probably/hopefully be okay" mentality. If you're going to spend hundreds, then go for it!

A lot of people have reported the emergency hatches leaking. I patched all existing holes in my roof/and cut a few new holes for 14" RV roof hatches, it's worked well for me and my metal vent hatch was about $30 shipped.

I'm sure if you tried you'd be able to make a custom fans to your setup no problem, the key is you have to spend time and try. Computer fans are probably a good place to start with that.

From my experience so far, most of the bus conversion is doing petty work (like removing rivets). There's plenty of time to overthink while you do mindless tasks like this. If you're anything like me, the more time you put into it though, the more likely you'll want to do it right.

Good luck!

[Scooternj]

Originally Posted by Geo Jeff

The small round vents in the roof at the front and back of my bus ceiling. What or how do they work. I assume they direct vent some how? Trying to decide if I need them or not for moisture control.

The vents are passive vents that allow the bus to breath. Keep them or not, is up to the individual owner. I plan on keeping mine, after putting in window screen and a 12v computer fan to improve airflow

[djthe3rd]

I tried living in my bus with polyiso on the walls/floor/ceiling @ 1in on floor 2in everywhere else and it was a miserable experience with 3 heaters and 2 ac's. You're fighting a losing battle with the metal box. It's either a freezer or an oven without good insul. Spray foam is the only way to go imo. Tiger Foams close cell is a ASTM E-96 class Class II Vapor Retarder (1.0 perm or less and greater than 0.1 perm) 1.67 @ 1" Foam It Greens closed cell is a Class III Vapor Retarder (10 perm or less and greater than 1.0 perm) 7.14 @ 1". Big difference if you plan on being in a tropical zone. I used 2 large tiger foam kits and put 2-3 inches on everything, now shes very very comfortable.

[superdave]

i used 2 kits in my 32' bus. that includes the engine cover and wheel wells. the cheapest ive seen a pro do it on these forums is 2400 bucks, double what the kits cost. there is no better than spray foam, just do it.

[AlleyCat67]

I just looked at the Foam-it Green site.... looks like I can do 1 inch on the ceiling and walls of my bus with 1 kit with a roughly estimated 525 square feet to cover, with 10% overage factored in.... I did not include the floor as I have other plans for that (foam board with radiant heat installed).

The project calculator on their site says you can do up to 730 square feet at 1 inch thickness with one kit, which means I would probably have enough material left to put the rest on my ceiling to add another 1/2 inch or so, since through the roof will be my biggest heat losing area besides the windows but I have an idea in mind for dealing with that too, but that was in another thread.

[New2Skool]

I started planning the foam insulating of my bus this summer and called a few local shops.
They all wanted 1,500 to 1,800 bucks to come and spray in three inches in the walls and 4 inches ceiling.
I happened to be in line at walmart and this young guy wearing a polar insulation tshirt was ahead of me.
He told me to set up a spray job and wait for the company to have a job somewhere and arrange it with the boss and drive your vehicle to the worksite to get foamed.
He said they would charge for material and a hour or two of labor only and save 1,000 bucks depending on how big the job is.
Have your bus taped, plasticed and prepared for spraying and you save more.
I haven't had it done yet but, one of our vendors had his new ford van insulated the same way. He drove about twenty miles parked on the street got foamed, left it over night and picked it up the next morning from the street.
So, that would help.

[tobeamiss]

does anyone know if the FoamItGreen will corrode the metal like the others seem to do?
and....I'm ripping down the ceiling first?
and last...can anyone explain the R value of 7 to 1 inch? would that convert to and r value of say 21 for a 3 inch coating on the ceiling?...