Insulation off-gassing and condensation questions.

[tacticalblack]

Do you guys think that possible off-gassing from sprayed polyurethane foam insulation would still be a problem if it is then covered with a product such as line-X?

I realise that this would be a pricey way to go, but I seem to lean towards sprayed polyurethane foam over more conventional methods such as fiberglass, styrofoam, Reflectix type products, etc., for the following reasons;

- Would probably reduce outside noise better due to its density
- Might even help a little bit with wall/structure rigidity (long shot, I know...)
- I figure that because the foam would infiltrate small areas and fill gaps, condensation and problems associated with it would not be an issue since there would be no air-space (please tell me your thoughts on this also)

Any information, comments, and input (especially from past experiences; both good and not so good) would be greatly appreciated. Thanks in advance, Kevin.

[mjeffrey]

In my research for my own conversion, I read that the spray-in foam has killed many a van - it was apparently the popular thing with 70s (?) vans, but ended up blocking drainage holes and capturing moisture, then holding it against the sheet metal until it rusted right through.

Having said that, I seem to recall someone on the forum here having used it, and possibly taking extra care to avoid spraying it near drainage areas. Only time will tell, I guess

No idea about off-gassing through Line-X. If you're concerned about off-gassing, then polyurethane foam is probably a bad idea, and you probably want to look at jute/cotton felt or fiberglass; if you think the dangers are overblown, then you're fine I've been unable to find any definitive answer.

Cheers!
Mike.

[tacticalblack]

Thanks Mike. I din't think that sprayed polyurethane could absorb and retain humidity. If that's the case, the Line-X could maybe make things worse, as moisture would not be able to escape/dry as easily. The idea is to build it right and make it last, so if it will cause rusting problems, then I need to find another way to insulate the van. I am however considering installing two (2) "FanTastic" roof fans (or at least one fan and one vent) to help with air circulation. Thanks again, Kevin.

[mjeffrey]

Hey Kevin,

I don't think it absorbs moisture - rather, it traps it against the metal. Not sure if the moisture is introduced later, or if it's trapped there during application (perhaps just the moisture in the air, or already on the metal surface).

I'm not an expert, though - I've just read about a few folks losing their vans to this stuff.

Cheers,
Mike.

[Scalf77]

One of the spray on materials you can look into is http://www.lizardskin.com/. I haven't looked at to hard and was actually thinking of spraying it on the top of the roof. For that reason I did not look into off-gassing. The off-gassing and the fact that it would plug the weep holes are really what help put it into the taboo side of insulating vans, I also believe that when the older stuff caught on fire it was plain toxic.

-greg

[tacticalblack]

Thanks guys. Lizard Skin Ceramic Insulation looks interesting; I will have to research it some more. I wonder what its R-Value equivalent is. Also, I hope that it is able to flex a little bit once dried (the Ceramic word scares me a bit...).

Going back to Sprayed polyurethane foam, would spraying the body with a product such as POR-15 (chassis saver rust preventative) prior to application take care of potential rust issues?

Thanks again, Kevin.

[LenS]

Our 2000 Chev. Express had sprayed in insulation (do not know type...now). Had to remove it from the roof area when we had the penthouse added in 2009. Saw no distress or rusting on the steel van skin after 8-9 years of use. The paint on the inside looked as it came out of the dealership. We have camped in the spring and late fall with the van over the years. Windows would fog up on those trips with moisture.

Have seen some poor jobs done when SMB has installed fiberglass insulation....missing pieces, gaps, etc.

The sprayed in foam REALLY made the van MUCH more quite. Plugged drain holes could be a real problem and should be discussed prior to having foam put in. SMB-I really had a mess when they air chiseled off the roof for the penthouse. I did remove a 6"-12"wide path of the insulation from the roof where they would be cutting. 6 months later still find insulation pieces in storage areas and corners.

Good Luck

[august]

Kevin-

I haven't worked with spray foam in vans, but due work with it in buildings almost daily. Polyurethane off-gasses horribly for the first few days. By day 7 there is not supposed to any additional off-gassing, some claim the off-gassing is only 48 hours. Our entire house is insulated with poly and I can say it smelled for about two weeks- then not a bit since.

It is an effective moisture barrier, so I think the concern would just be trapping moisture frome plugged drainholes, or if there is some route water can get down behind where you insulate, it will not ventilate and therefor never dry.

August

[saabman]

Hi just my 2 cent:

I am planning out my Chevy Express conversion V.2 and I think the idea is the best insulation should have a space between the steel and the insulation (whatever it my be) then have a water resistant layer which should catch any condensation and allow it to run off without damaging interior or exterior parts...

But that is only theory and we all know that theory...

[billwilson]

FWIW : POR-15 is THE treatment of choice for old rusty VW vans
guys swear by it

i have no personal first hand with it, but the posts on www.thesamba.com under Vanagans
really tell a story