Insulation Recommendations

[LisaH]

The tear out of my 31' Sovereign is just about complete, and it's time to set sights on insulation. I've narrowed it down to the Reflectix (silver bubble type) or the R-Tech Insulfoam sheeting. I am chemically sensitive, and plan to use my Airstream for a safe living space; so this plays into my choice of materials.

Also - any tips on application. My ex-husband is providing some help on the project, but most of the direction lies on me, and I'll confess I'm a bit overwhelmed. Is the insulation best applied to the inside of the exterior skin, or the outside of the interior wall. Are air spaces preferable? Is there an adhesive that is somewhat "non-toxic"?

Any help or direction is welcome.

Thanks,
Lisa

[calais66]

Well, I'm sure you're going to be in for no shortage of opinion or advice on this topic

I'd suggest using both foam and reflective insulation together. From my understanding, reflective is meant to be used in conjunction with other insulation (foam, fiberglass, whatever), not just by itself. If you do end up using both, make sure you're creating a 'dead air space' between the reflective and the wall.

[Protagonist]

Consider Prodex. It's a foam insulation sandwiched between two reflective layers, and comes in two thicknesses, 5mm and 10mm.

[perryg114]

RMAX is a rigid foam with foil on both sides but a radiation barrier in addition to real insulation is a good idea. The foil on the RMAX acts a radiation barrier but it probably not quiet as good a the shiny bubble wrap stuff (Reflectix). I would use 2 layers of 1/2" RMAX and 1 layer of the bubble wrap. I just used the two layers of RMAX. If it were on the roof area, I would use the bubble wrap stuff as well. The bubble wrap is going to do the most good on sun facing areas.

Perry

[Belegedhel]

As you do your research, be sure to read the small print about installation requirements. Some of those shiny bubble wraps make some pretty dramatic claims about R values (R16 for instance), but when you read the small print about requirements for installation, you find that they require several inches of air gap to be effective. Do a search for "insulation" on these forums, and you will find a plethora of opinions and arguments. I recall one of our members actually doing some tests using a variety of the popular products, and coming to the conclusion that for the space you have to work with, the pink fiberglass is just as good as anything. Bear also in mind that regardless of how high-tech you can go with the space between your walls, your windows will be, by far, your largest source of heat transfer.

As to installation, you want to install the insulation on the inside of the exterior shell, and then just slap your inside skins in place when ready.

I'm at roughly the same stage as you. I have put my plastic endcaps back in place and used the pink stuff against the shell, and put a layer of reflectix against the plastic caps, just because I had a roll of it handy. Haven't quite committed to what I will do for the rest of the trailer yet. The pink stuff, though itchy, is certainly easy to use. I just use spray adhesive on the inside of the shell, and then slap a split thickness layer of fiberglass in place. I then chink the gaps with stray pieces. The reflectix was then glued directly to the plastic caps with spray adhesive. I could do it this way since there are no/few ribs in this area. Wouldn't go this route for the rest of the walls.

The spray adhesive might not fit your chemical free requirements, but you might find products like the foam board out-gas over time, and won't be a good fit either. Not sure how inert the fiberglass is, but at least it doesn't have a smell to it.

good luck!

[perryg114]

Pink stuff is the devil. It sucks up water and promotes mold growth. The pink stuff is a partner in crime with rear end floor and frame rot. I think it is also responsible for a lot of musty smells in an old trailer.

Perry

[Belegedhel]

Eh. I wouldn't go so far as to recommend the pink stuff, but it sure is easier to bend it around a curve. I don't see it as being anywhere near as capable of "wicking" as many believe--the best prevention for mold and rot is to keep the water out. Definitely wouldn't install it under my subfloor, but that is a nice flat surface that is easy to install foam board against.

Also in my personal experience the funky smell is the result of a rodent infestation. Granted, they make a nice habitrail our of the pink stuff--don't know what kind of mess they would make of some other material.

[putback]

And there is another to consider, yellow stuff. Got the idea from professional commercial heating and ventilation contractor. Its used to insulate and sound deaden metal ductwork. Like the pink fiberglass but a bit more dense and 1 1/2 inch thick. Put it in one 5 years ago, very pleased with the stuff. Don't let this out, its less expensive!!

[Belegedhel]

Where do you get the yellow stuff?

[putback]

I got mine locally, privately owned construction supplier. The contractor called the supplier and allowed me to cash out what I needed under his account. I'll try to find the product name and post it this weekend.

[65CV]

Chemical Sensitivity is a very broad description -- if you can narrow it down a bit, it might help in recommendations.

I have an Engineering background and did a lot of research on insulation before deciding on our path. I came to the conclusion, based on a lot of great work by others on this forum, that the reflective insulation is best for warmer camping and a fiberglass or wool-type insulation is best for cold camping.

We chose a multi-layer Prodex installation, using thin strips of Prodex glued to the outer wall, then a layer of full Prodex, followed by another layer of thin strips running at a 90 degree angle to the first strips, followed by another layer of Prodex. It was a lot of work, but works well in our camping style. The air gaps formed by the thin strips are a huge factor in efficiency.

We used a construction adhesive. If you decide to use a method like this, you may be able to modify it by:
(1) minimize use of any adhesive by carefully cutting the panels so that they press-fit into each cavity. With two layers back to back, you'll miss some air space and efficiency, but will have no chemicals except for the bubbles in the Prodex.
(2) find a good water-based adhesive that will hold things in place as you assemble like we did, providing that you don't have issues with the adhesive
(3) if you have major issues with any adhesive, consider a triple layer of Prodex/Reflectix, held in place with thin aluminum strips riveted behind the face of each rib

Keep an eye on insulation4less.com (I think that is the right link). If you sign up for their offers, they will infrequently run a 1/2 price sale on Prodex. I have used both and prefer Prodex for its quality and r-value.

As mentioned earlier in this thread, the windows are a MAJOR contributor to heat gain or loss. We have cut a panel of Prodex the size of each window and put them behind the screens in extreme hot or cold weather. The difference is amazing.

Standard blown or rigid foams are full of isocyanates and urethanes -- I doubt these would work for you.

[putback]

Originally Posted by Belegedhel

Where do you get the yellow stuff?

The brand is Certianteed Soft Touch duct wrap. Fiberglass w/ heavy fiber reinforced reflective backing.

[cameront120]

If you want a batt type insulation don't use fibreglass, it retains moisture and the r-value degrades. You might be better off with an insulation made from rock slag, such as Roxul. It's hydrophobic, so will repel water if it comes in contact with the insulation.
Has anyone experimented with aerogel insulation?

[LisaH]

Thank you so much for your detailed and informative response. I think I'll go with the Prodex as you and many others have recommended.

I'm sensitive to solvents, chemicals, glues, mold... and trace amount of carbon monoxide, so the trailer will have to be all electric. Back to the insulation issue - I'm curious, is condensation between the walls common, and if so are there any tips on how to decrease the chances of this becoming a problem (i.e. mold).

Guess the next task will be narrowing down the least toxic adhesive and calking for the windows and exterior shell.

Thanks again!

[LisaH]

Thank you for such a detailed and helpful response.
What thickness of the Prodex do you recommend?

Lisa

[LisaH]

What thickness would you recommend? and any installation recommendations you'd have based on your experience?