Fiberglass body + insulation

[Morningstar]

Hi All! 

I'm redoing some parts of my sunrader (tearing out the back wall, and the horrible carpeting on the ceiling around the sleeping quarters). It seems most folks posting here have a metal body van; mine is fiberglass. When I tore out the back wall and carpeting, it exposed the fiberglass outer shell. I was thinking of using reflectix and a spray adhesive to stick it to the fiberglass, but I'm not sure that that is the best route....(reflectix needs that air gap n all) I'm planning on going south in the fall and I'm not 100% certain what type of climates I will be in. Any thoughts on what type of insulation n how to install it with fiberglass? How necessary is a vapor barrier?  

Thanks!

 

[Almost There]

Hi All! 

I'm redoing some parts of my sunrader (tearing out the back wall, and the horrible carpeting on the ceiling around the sleeping quarters). It seems most folks posting here have a metal body van; mine is fiberglass. When I tore out the back wall and carpeting, it exposed the fiberglass outer shell. I was thinking of using reflectix and a spray adhesive to stick it to the fiberglass, but I'm not sure that that is the best route....(reflectix needs that air gap n all) I'm planning on going south in the fall and I'm not 100% certain what type of climates I will be in. Any thoughts on what type of insulation n how to install it with fiberglass? How necessary is a vapor barrier?  

Thanks!

When working with a fiberglass shell one needs to not only think about how to install the reflectix/insulation but how the interior walls are going to be finished. Yes, you can glue bubble wrap/reflectix to the fiberglass shell but then what do you attach the interior finishing to?

My fiberglass high top had absolutely no way for me to attach anything to it except with adhesive since it was a single wall shell - some are double hull and you can carefully drill in to the interior shell without damaging the integrity of the outer hull.

I used small pieces of 1 x2 and 1 x3, so they would conform to all the curves, mounted on the fiberglass with PL Premium construction adhesive. It was slow going getting them all attached and since that time some of them have broken loose. If I were to do it again, I'd probably go with fiberglassing the wood to the fiberglass shell.

Once you have mounting strips in place then you can install reflectix/bubble wrap combo by stapling it to the wood and apply whatever interior finish you want by screwing in to the mounting blocks.

Because I never intended to be in colder weather and was only concerned with heat, I used bubble wrap to create a dead air gap and then reflectix stapled to the wood mounting blocks.

IMO vapor barrier in an RV is totally unnecessary, you're better off planning on good ventilation to reduce condensation than to worry about trying to create a vapor barrier that would be extremely difficult to have totally moisture proof.

 

[highdesertranger]

for use when ridged foam board is not an option, I like Ensolite closed cell foam. it comes as peel and stick or plain. it is what old backpacking sleeping pads were mad of. I have slept on an Ensolite pad on snow and was not cold. sometimes you can find the sleeping pads at military surplus stores real cheap. here's a site just to show you what I am talking about, http://www.foammart.com/index.php?nsc=ensolite&pcat=closed-cell . most upholstery shops will have it. with the smaller thickness it is very easy to conform to uneven surfaces and corners. highdesertranger

 

[Morningstar]

Thanks guys! I got some 1/2 inch polyiso, and there are a few mounting boards in there, and i'm going to install one more board across the back (which there was one there when i did the tear out.) I'm going to liquid nails the wood to the fiberglass shell and then stuff the polyiso in there (staple it i guess!) then screw the wall panneling to the wooden boards! Namaste!

 

[highdesertranger]

I have seen liquid nails mentioned in a few threads. in my experience it only holds for a couple of years. after all it is designed for stationary applications and not the vibrations of a vehicle. so have you guys and gals had a different outcome? highdesertranger

 

[Morningstar]

Hi! Thanks again for the responses, also the thread about adhesives and fiberglass was super helpful! I might try the E-6000 for something! Ok, so around the bed area, I'm tearing out the (disgusting and *moldy) padding and fabric. I'm going to reseal the windows to prevent future leakage! I would like to insulate and put new carpet in... thinking of how to do this. Maybe put a wooden anchor across (and glue it with the e-6000) the fiberglass top, then do (in the following order)

Fiberglass shell
bubble wrap (for the required air space),
reflectix,
bubblewrap (does it need a second layer of bubble wrap here?)
carpet pad/some type of foam,
carpet (low-ply/berber).

I guess the best bet would be to screw/staple the carpet to the wooden anchors? Does the insulation(bublewrapp n reflectix) need to be glued/adhered in any way, or will the securing of the carpet hold it in place?

 

[Almost There]

Hi! Thanks again for the responses, also the thread about adhesives and fiberglass was super helpful! I might try the E-6000 for something! Ok, so around the bed area, I'm tearing out the (disgusting and *moldy) padding and fabric. I'm going to reseal the windows to prevent future leakage! I would like to insulate and put new carpet in... thinking of how to do this. Maybe put a wooden anchor across (and glue it with the e-6000) the fiberglass top, then do (in the following order)

Fiberglass shell
bubble wrap (for the required air space),
reflectix,
bubblewrap (does it need a second layer of bubble wrap here?)
carpet pad/some type of foam,
carpet (low-ply/berber).

I guess the best bet would be to screw/staple the carpet to the wooden anchors? Does the insulation(bublewrapp n reflectix) need to be glued/adhered in any way, or will the securing of the carpet hold it in place?

IMO, the second layer of bubble wrap will not be needed. Unless, you're wanting to try to use the reflectix as a reflective barrier to trap heat that you produce by way of a heater, inside the van. A small heater such as the Mr. Buddy is more than sufficient to heat the van. I'm not sure how efficient it would be in any case.

When I did my van I cut the reflectix to fit between the ribs of the van and then used 3M Super 77 glue to adhere the bubble wrap to the outer side of the reflectix. BTW, you'll want the 5/16" bubble wrap at a minimum, thicker is better but harder to come by.

Once the panels were assembled I used metal tape to fasten the panel all the way around to the ribs. Since you're working with a fiberglass shell, you might want to stick the assembled panels to the fiberglass with the metal tape (test the tape for adherence first) and then tape the next panel almost overlapping the first panel to create a seamless installation.

Way back in the 70's carpeting the walls was fashionable (shaggin' wagons) but we only used the vans for weekend trips. Carpet absorbs moisture, dirt, odors and everything else. I would seriously recommend that you think about putting something other than carpet on the walls of the vehicle. Yes, I know that a lot of the fiberglass trailers come with some type of carpet on the walls inside but that's not to say that it's a good thing. Vinyl would be a better choice if you have to have something that is really flexible. Panelling or wood finish is another alternative.

 

[highdesertranger]

if you choose carpeting, Hull Liner is a better option. here's an example, http://www.yourautotrim.com/huhfa.html . highdesertranger

 

[4GNomad]

Awesome... This Hull Liner is what I needed as I wanted to go this route after the insulation is installed. Thanks for the info and link.

 

[Morningstar]

http://www.thefoamfactory.com/closedcellfoam/polystyrene.html (i don't know how to make it clickable, so maybe copy n paste?) I was thinking this material polystyrene for below where my sleeping pad will go (it looks super cushy!) and it seems to have a high r-rating. What do you guys think? The sleeping space is lofted above the driver n passenger seats. Then for the roof above the bed i was thinking either the self-adhesive ensolite that highdesertranger mentioned or the reflectix with bubble wrap.... wich do you think would be better. I'm going south first and it will probably still be super hot (i'm leaving August 1st, and will be in AZ around mid/end of September I think...) So I'm not sure which choice would better keep heat out?

 

[Morningstar]

Just was doing some price comparison, and it seems like all the supplies i will need for the reflectix would be about half the cost of the ensolite, and about the same as the polystyrene... so the question is... is polystyrene any good/ better then reflectix/ higher r-value than reflectix?? and if so , maybe i will go that route and layer it as follows

fiberglass shell
foil (nessecary?)
polystyrene (which is kina thick.. an inch i think?)
carpet/hull liner

and then..... how to mount it to the roof securely?!?!?!

 

[akrvbob]

Reflectix has 0 R-Value. Reflective materials are not an insulation and there are NO government or industry standards for a R-Value on them--because they don't have any! Without standards, anybody can make up any number it wants. So Reflectix the company made up a number out of the air about R-1. It's meaningless.

Use styrofoam--or even better, polyiso!
Bob