I used 3M General Trim Adhesive 08088 spray installing the foil side of foil/bubble wrap insulation directly to the bare metal walls and roof---not a single piece has yet to lift off or fail to stay stuck. Of course this isn't something to use if you hope to remove it later. I simply sprayed each surface lightly then immediately put in place---this allows a quick adjustment if needed. Once its stuck in place, all wrinkles smoothed out its pretty much there until you wrestle it off.

My idea is any interior insulation cuts down on the condensation found in a no-frills bare walled cargo van suffers. Think of Club Wagons which aren't all that well insulated apart from the interior panels mostly plastic and a smattering of automotive matting.

When I use the pink fiberglass its the unfaced stuff---the paper vapor barrier could be an issue so avoiding it altogether seemed the best move.

Not familiar with the Roxsol but from these forums learned about Dyna-Mat and Reflectix (??) Oddly enough I'd discovered some Reflectix-like material several years ago and have now done two E250's using it.

 

Mark III had installed fiberglass in several wall / cavity locations in my conversion vans.

Vapor Barriers are necessary to separate 2 areas of significantly different air temperature / humidity. These are exterior walls. In van applications, Vapor barrier would go between the pink insulation and the interior wall finish.

We use Roxsul now in most construction projects to be LEED-certified. It is more expensive, but it is a great product. The exterior wall application is different from the interior walls. The Interior Roxsul has a sound-deadening quality to it.

 

I don't know where to start. When fiberglass is smashed it loses its R value, not my opinion but I have read that in many places. Vans move, so the fiberglass is also moving. As it moves it leaks out to all kinds of places, mostly the interior, unless it is sealed from the interior compartment. I owned a van conversion company here in New Mexico for 20 years and have seen all kinds of insulation for vans. I have been in vans that made me itch immediately from the fiberglass used in that van. I'm sure some people tolerate that itching much better than I. I have also itched from conventional batteries used in vans without venting to the outside. That really itches me, and probably others too. If you read up on current insulation practices you will see that probably the best thing is to use the foil both sides bubble material along with an air gap. When you read what I have read you will see that an air gap is preferred because it is such a good insulator. I could go on and on, but I'll spare you guys.
Rick
Albuquerque

 

I grabbed a roofer/skin guy and asked him to break this down for me: basically JWA your foil bubble wrap is a fancy Ice & Water Shield. A vapor barrier would not be necessary in your case.

 

Rick: forgive me for being skeptical, but I just can't see the double-foil bubble-wrap as an insulator. What is its R-Value? What products (make & model) do you use? Can you provide a link to its cut-sheets?

 

From a quick research I learned that the foil bubble wrap is a "radiant barrier" not "insulator" and as such has an R-Value of 1, regardless of what its Mfrs may claim.

A more accurate measurement would be the R-value of the ASSEMBLY that contains the double foil bubble wrap. Evidently this is controversial product even as a duct wrapper The Foil-Faced Bubble Wrap Sham - Understanding Radiant Barriers

My roofing guy actually wasn't that far off calling it an "fancy ice and water shield".

 

Hey Henry---totally agree I've got nothing more than a fancy ice and water shield! I did read the hype and found it completely unbelievable but bought anyway because it would work as a damper for the bare metal walls. That it cuts down some of the inside condesation is an added benefit and with a double layer on ceiling and walls there is a noticable insulating value as well. Most likely that's due its in contrast with nothing at all.

When my long term refit is finally finished I hope to have additional inner panels of 1/8" plywood and acrylic textured sheeting with perhaps the Johns-Manville white unfaced insulation batts properly laid in behind. Same treatment with the roof and a remotely possible relocation of a rear heating until closer to the floor instead of ceiling mounted.

As is once the interior is warmed to an acceptable temperature its easy to maintain. Having a separator curtain essentially gives me two zones which can be independently heated. Cooling is only important in the front so the curtain is an efficiency boost for the standard A/C----one could hang meat during the summer!

FWIW I bought my foil/bubble wrap 4' x 120' for about $130 shipped in via UPS. So far that one roll has taken me through one standard E250 and my current raised roof E250 each with the double layers. Although the raised roof ceiling was insulated with pink fiberglass that's not a bad investment if just the square footage alone is considered. I have enough left to make a few sets of solar shields for the front doors to augment my Intra-Tech windshield shade and covered the inside of those same front doors.

I guess we all find what works best for us and it seems there's more than one good way to do this. The only issue is the expanding foams which would trouble me with the possible moisture trapping issues.

 

Absolutely, there is more than one way to skin the cat. Rick is bringing some important points to van's insulation. Although I am not convinced by him when advising to use only the double-foil bubble wrap with air-gap, at least he brings up the importance of securing the fiberglass and encapsulating it well.

Another product that has become very popular around here for heavy-traffic floor systems is VersaRock, as opposed to plywood. I would think for you guys using vans as work stations it might be beneficial to bring it up. I did not use it on my van.

On my van I used fiberglass where I could, and on tight clearances I used either foam or duct wool (similar to Roxsul). I re-did the carpet with regular carpet padding over plastic.

We never had an issue with itching. Of course I stuffed the fiberglass well, secured it with ties, and encapsulated with the finish systems (usually plywood and fabric).

I used car-hood (foil) insulation at the doghouse. Under the van I spent a lot of time and effort, POR-15, then undercarriage spray. I also build a fiber-insulated sheet-metal trough for the under-the-van AC and Heater lines.

Undercarriage spray was used on front (electrical window) doors as well. I was afraid of jamming the mechanism if I used any other kind of fiber.

Loved the feeling and the door-thumping sound.

Insulation is one side of the coin -- the other side is proper ventilation. Speaking about ventilation -- I did install a thermo-switched Exhaust Fan and ductwork in the rear / upper part of the turtle-top. That fan alone helped a lot with ventilation in the summer. It ended up being powered by solar panels I installed on top, with a normal manual override.

 

I have an extended window van and I used this stuff to make sun shields for all of the windows. The rear side windows I keep in place all of the time, even when I'm driving it. The difference between no shields and shields is about 30-40 degrees on a sunny summer day. I use the van to tow my race car, a place to change into my driving suit, store all my tires, tools, etc. and as a place to sleep at night.

 

Does make a big difference--and has a few added benefits too.

Van was broken into sitting in my driveway (before installing alarm) and I swear it was to steal a Sony CD/AM/FM receiver---little did the crooks know they'd have to fall over about $1700 worth work tools. Thinking if they couldn't see it they might not be so prone to try again adding a curtain between seats and cargo area, full windshield sun sheild and the side pieces too its nearly impossible to see inside now. So far no return visits for more of my stuff.

I got the idea from RV's and stored aircraft so thought it would work just as well for a parked vehicle. Keeping it in place regardless the weather makes it seem less suspicious at least in my mind. Hot summer days I'll start the A/C and let it cool the front area before heading off---makes an enjoyable job. With the Autoware black Cordura seat covers this thing would be very hot otherwise.

Rear area windows are double tinted which allows some light inside during the day if needed but the curious have to get close and shine their own light in to see anything at night.

Works great----glad to see I'm not the only thinking in this direction!

 

well I got both of my walls insulated and the 1/4 sanded plywood up. looks pretty good im happy with the how it looks, sounds, and feels. I think ill us 3m adhesive and the foil stuff on the front cab are under the factory mat and insulation, and on the firewall and inside the front doors. I really want this thing to be as quite as possible, I hate road noise but I don't mind the thrush welded mufflers growling a little, although the walls almost drown them out too. as for the roof ill probably use the foil backed foam board insulation becuase it has a decent r-value and its thin to conserve valuable head room, still need to finish my high top for that though.