Insulation and Mold Links

[EastCoastCB]

Mineral Wool is hydrophobic. From the dictionary: tending to repel or fail to mix with water. If fiberglass insulation becomes wet, you end up with a wet lump of glass lint, with no insulation value to boot. Mineral Wool on the other hand will not become wet. Water in fact beads up and rolls off the surface of Mineral Wool. This promotes water draining and drying if the wall cavity becomes wet, rather than holding water like a sponge. Which would you rather have in your wall?

Modern House Plans by Gregory La Vardera Architect: What you don't know about Mineral Wool will make you look stupid.

https://www.youtube.com/watch?t=3&v=gLDxhbKfVeo

[EastCoastCB]

https://www.youtube.com/watch?v=8NC79e0oztM

[EastCoastCB]

Would make a PERFECT insulation material for just behind the cab and over the engine.

https://www.youtube.com/watch?v=7rbRYs0XEAM

[nat_ster]

Great info.

Thx for spoon feeding us.

Nat

[EastCoastCB]

Not spoon feeding, just sharing the info.

[family wagon]

Mmm, spoon-fed yogurt. (this is the same thread as the recent dairy metaphor, isn't it?)

I hadn't heard of/noticed the Roxul products before. The Lowe's in my city doesn't carry it but several others nearby do. Seeing how neatly it cuts, it'll be just the thing for fitting around my engine firewall. It may be good stuff for lining the future generator compartment too. Thanks!

[CaptainInsaneo]

It isn't that common, it costs more than the pink stuff, and it reminds people too much of asbestos (WHICH IT ISNT). It is made from limestone that has been put into a machine that, well I would call Satans cotton candy machine. It melts the limestone and turn it into threads which get glued together. That glue is what will probably determine how much water gets absorbed. Roxul is just a brand name, like kleenex, ask for it and you will probably get some rock wool product it just might not be Roxul. And for all of you who want to do a wood stove rock wool steel studs and concrete board makes a unburnable platform and surround for a stove.

[nat_ster]

Originally Posted by EastCoastCB

Not spoon feeding, just sharing the info.

Lol

I was just saying thanks for doing the research for us.

Nat

[EastCoastCB]

Originally Posted by nat_ster

Lol

I was just saying thanks for doing the research for us.

Nat

No problemo!

[Jman6631]

Hey nat ster, I didn't see you mention two-part foam name brands. Do you have any to recommend?

Thanks in advance!

[nat_ster]

Originally Posted by Jman6631

Hey nat ster, I didn't see you mention two-part foam name brands. Do you have any to recommend?

Thanks in advance!

Welcome.

I see that was your first post.

No, I don't.

This is due to the lack of names on the drums of chemical the contractors here use.

Most I have seen come from Dow Chemical Canada.

Things will be different where you are.

Nat

[family wagon]

The Dow product might be Froth Pak. In addition to that vendor, Lowe's lists it as available for order on their web site (to my US store). I'm thinking long and hard whether to go with this one. Probably will get one kit, at least, for spraying a few spots "along the way" as I re-assemble things down behind the chair rail etc. Not sure yet whether I'll go all-DIY or hire a contractor to do the main part of the job.

[Jman6631]

Thanks nat ster...the search continues...

One thing I haven't seen mentioned yet is the use of spray on undercoating. I've used it with success on other vehicles but never on bare metal. Would it perform any differently than the 'tar' used to affix the roof insulation, that is, trapping moisture between it and the metal and encouraging rust?

Is it evil and to be avoided?

Thanks in advance!

[efgjr]

I've removed 2 random lower panels and got into 2 spots in ceiling . Dry yellow insulation in all4 spots. Im game for pulling it all off if its still the popular opinion. Doing some post surgery healing and plotting my path after Im done. Thanks

[Poznos]

Has anyone done anything in the way of insulating the windows themselves to reduce condensation on them in the winter? I've been thinking about welding some pieces of angle iron into slightly larger pieces that would run the length of the bus. Then attaching those above and below the windows on the outside to form a track that you could slide some Plexiglass into to form a seasonal dual pane window.
Thoughts?

[nat_ster]

Just replace the windows with something real.

I don't understand why people keep trying to work backwards on here. Get rid of the $hit windows.

Everything you try to do to keep the junk windows in going to cost more money than replacing them.

Nat

[KrissyLeigh]

After reading every post I could find on this forum about insulation I am a lot better off than when I started, but I still have a few questions...

I won't be using spray foam, though I wish I was seeing as though it solves the problems I will face, but I cannot use it. So let's pretend it doesn't exist.

We have a '95 BB TC2000 Cumins 5.9 with an Ali Tran. She's a flat nose front engine, a big girl and even has under bay storage compartments and a side and rear exit. I'm in love and want to do this right!

We are stripping our bus down to the outer skin to clean and then re-insulate. Trashing the old insulation. I was going to clean and de-rust the entire interior and then paint with rustoleum and then fix all holes. Is it wise to paint the interior ceilings and walls with rustoleum as well.
We are also following advice to paint the roof with 2-4coats of the reflective paint you have all spoke about.
But back to the interior.
I will be using rigid styrofoam board for all surfaces, floor, ceiling and walls. Nat_Ster as you recommended I will be using the 300psi board for the floor.
My question is, what to do about a Vapor barrier with the rigid board? Can I use Tyvec between the metal skin and rigid board?
Can this be used on the floor as well?

To reduce heat sinks and thermal bridges my plan is to use adhesives to attach the vapor barrier and rigid foam to the bus. Any suggestions on favorite adhesives? Liquid nails?

How will I secure my interior framing for bathroom and interior walls and cabinets to the bus without creating a heat sink?

Also, I am worried about the metal frames in the bus causing thermal bridges and nullifying all of our insulation. Can I cover these with something? I was thinking the foam tubes we use for hot water pipes in homes? Would this work? Can I use an adhesive to adhere foam to the framing bars on ceiling and walls?

I want to insulate right the first time, avoid heat sinks and thermal bridges and also condensation, as we all do.

I know his is a lot of questions and I'm sorry; but one more: do I need to create a space between the insulation and the interior wall for it to work properly? How big of a space? How do others accomplish this?

Thank you in advance!!!!
-KrissyLeigh

[family wagon]

Originally Posted by KrissyLeigh

I will be using rigid styrofoam board for all surfaces, floor, ceiling and walls. Nat_Ster as you recommended I will be using the 300psi board for the floor.
My question is, what to do about a Vapor barrier with the rigid board? Can I use Tyvec between the metal skin and rigid board?
Can this be used on the floor as well?

300 is probably PSF, not PSI (per foot, not per inch). The Tyvek you're thinking of must be house/building wrap? Its purpose is to shed liquid water that gets behind exterior cladding before the water reaches the interior structure and to reduce air in/exfiltration. It isn't a vapor barrier. Some foam boards are good enough to stand as vapor barrier on their own. Dow's blue Styrofoam brand, an extruded polystyrene ("XPS"), is an example. Owens Corning's pink Foamular is another. Note that the board made of white pellets we in the US often call styrofoam isn't Styrofoam; that stuff is expanded polystyrene or "EPS". EPS normally isn't a vapor barrier, but I think it's sometimes available with foil facing and foil is a vapor barrier.. For XPS to serve as a vapor barrier its joints must be sealed well. There is tape made for this, and the cans of single-part spray foam may be a good option for sealing edges of foam board too (make sure the solvents in the spray are compatible with the foam board). It's important to make the insulation thick enough that you won't just get condensation on the inside surface of the foam. For the ceiling, you might consider using multiple layers of thin board. The thinner stuff can bend to follow the roof arch more easily. XPS can be used in the floor too, but do put something over the top of it to spread loads. Dropped objects, footsteps that don't land perfectly flat, etc are enough of a focused load that they'll dent XPS if they hit directly.

Originally Posted by KrissyLeigh

To reduce heat sinks and thermal bridges my plan is to use adhesives to attach the vapor barrier and rigid foam to the bus. Any suggestions on favorite adhesives? Liquid nails?

IIRC there are several different products with the Liquid Nails brand. You'll have to check the labels to find a product that is compatible with your chosen foam: solvents in some adhesives will actually dissolve foam!

Originally Posted by KrissyLeigh

Also, I am worried about the metal frames in the bus causing thermal bridges and nullifying all of our insulation. Can I cover these with something? I was thinking the foam tubes we use for hot water pipes in homes? Would this work? Can I use an adhesive to adhere foam to the framing bars on ceiling and walls?

I'm planning to make my insulation thicker than the height of those frames/ribs so the innermost layer of insulation will run continuous over the inside face. It'll be thinner there than other places, but insulation is never uniform thickness because of structural things like this. If your insulation won't be thick enough to cover the wall structure then yes you could wrap the protruding bit of ribs with some kind of foam. In my opinion pipe insulation wouldn't work so well because it wants to keep a round shape. Maybe instead you could take some thick foam board and cut a groove into it so it fits over the exposed part of the rib. Or build up the same shape by with layers of thinner board.

[jwilcox]

Awesome thread, just the info I'm needing for where I'm at now in the planning process of my build. So.....my plans at this point are to take out the old insulation and skins and replace that with 1.5 inch EPS boards which I got for a song after being reclaimed from an old chicken house (upcycling is super important to me!). I plan to use one layer of this foam in the floor, then install a 1/2" subfloor, then hardwood flooring. In the walls and ceiling, I plan to double the foam for a full 3 inches, followed by some sort of thin paneling. My question is in regards to the vapor barrier: WHERE does it need to go, ie, glued onto the metal BEFORE the foam OR on top of the foam on the inside OR BOTH?? WHAT are good vapor barrier materials? I've been looking at 6ml plastic sheeting.....alot of the shiny types say they are a heat barrier, not a vapor barrier.
Ideas?

Jamie and clan (ie children
PS I think I've become a full busaholic, at least it seems that way with how obsessed I am to plan this out and get all the stuff together for when the demolition starts in just a few days!!!

[charles_m]

eps board insulation has about 1/2 the r value per inch that poly-iso foam has and the same r-value as fiberglass. Because space is so limited in our wall and floor cavities, I would never consider using it, even if it is free. if you're going to the trouble, buy poly-iso, at least for the floor and ceiling. I have close to r20 in my walls and a little over that in my floors and walls. I can stay at 70* in my bus (10 window) with nothing more than a space heater in 10* outdoor temps. If i could do it again, I'd do another inch in my floor and ceilings. Those are, by far, the most important places to insulate but also the most challenging due to headroom limits.

The shiny reflective stuff can function as a vapor barrier if you tape all the seams.

I put the vapor barrier right behind my finished walls, over my strapping/studs. The idea was to keep moist interior air from getting to the cold inside metal where it would condense to water. My bus is spray foamed as are the buses I build. It can act as a vapor barrier depending on the installation, but I still like to throw in a layer of reflective radiant barrier over that to seal it all up. Every bit helps!

EPS is garbage. lol i sound like a crank, but you gotta get serious when its insulation time and all that stuff will do is trick you into thinking you've made a big improvement when you've really only made marginal gains over the stock setup