Community Forums

Highgturn · 07-23-2007, 09:33 AM

MaryJane,

PI uses the fiberglass for all of its insulation. For 2007 they are advertising R10 sidewalls and R17 in both the ceiling and floor. Personally, I don't know if it is superior to the solid core Styrofoam used by some manufactures or not. It does seem likely that the fiberglass will fill more voids and be less likely to have cracks for warm/cold air to escape.

camperguy · 07-23-2007, 11:08 AM

Mary Jane..PI uses fiberglass insulation. Fiberglass has a higher R Value per inch than any other type of insulation, that is why it is used in homes and commercial buildings. A leak can be a problem with any type of insulation. Fiberglass can get wet, but when it dries out again, it will still have the same R Value as before.

Dale Tomlinson · 07-27-2007, 08:10 AM

camperguy,
Unfortunately, that is not true. Styrofoam insulation has 2 or more times the R-value over fiberglass insul, but is much more expensive. Thats reason more fiberglass is used in homes & buildings. Certain types of polyearathane foams are even better, but also much more expensive. I have spent 42 years in construction, using all types of insul.

Dutch_man39 · 07-27-2007, 10:25 AM

Dale,

I see that NuWa uses high density blue polystyrene foam which is bonded in their sidewall construction. They claim this is stronger by 25% over the white bead foam and it resists water much better.

Is this what you are talking about in your post?

Bill

wrongway · 07-27-2007, 10:55 AM

Maybe in the construction side of insulation styrofoam maybe a stronger style of insulation, that is not true in the RV Industry. What full styrofoam insulation is used for in the RV industry is to keep the walls from sucking in. Block styrofoam is place between the studing to keep the walls from coming in on a, what is called, vacuum bond walls. The place the walls under a large canvas blanket, secure the side and ends and suck the air out of the cavity to get the walls and glue to adhere. The styrofoam keeps the walls from "sucking in". You will not see a "True" 4 season coach with styrofoam insulation in it. They will all have blanket to insure that insulation factor in the unit. A unit that is insulated with styrofoam is going to be a aluminum framed unit and if in cold conditions you will see moistures on the studding on the inside. The blue board that Nuwa is using in a moisture barrier effect to keep the moisture from coming. In the end Blanket Insulation is the best for a full time style unit.

ChiefJohn · 07-27-2007, 02:01 PM

Tom, aka "wrongway", thanks again for sharing your RV knowledge and experience with our Excel owners.

Dutch_man39 · 07-27-2007, 05:09 PM

Wrongway,

I realize this is an Excel forum and you sell Excel. I'm not knocking Excel. They are on our short list of 5th wheels to buy within the next year.

However, to set the record straight the Blue Polystyrene Foam was developed by Dow Chemical 50 years ago and is used widely in convential stick built buildings and according to Dow provides superior insulating qualities.

Take a look at the NuWa website and watch the video of a 1 ton pickup driving over several different samples of RV sidewall construction. The only one that didn't collapse is the NuWay pressure laminated wall with the Dow Blue Foam!

MakinSmoke · 07-28-2007, 03:16 AM

"The only one that didn't collapse is the NuWay pressure laminated wall with the Dow Blue Foam!"

This demonstration would clearly show strength but doesn't necessarily show insulation quality. Blue foam does appear to be stronger but is there a demonstration showing that is superior in insulation quality?

Quote from NuWa site
"NuWa's use of Blue Dow foam in sidewalls does create 25%+ greater insulation than most RV's. The floor and roof are extremely well insulated with blanket insulation and/or high tech materials."
I can find no "proof" of the 25% statement, just the manufacturers statement. They actually go the other way and say "R-factors" are not used because they are not relavent.

In a further FAQ they say...
"Is the Blue Dow foam insulation NuWa uses really as good as they say?
Yes, probably better. The rest of the industry typically uses white bead foam insulation board. The same thickness of Blue Dow foam has more than 25% greater strength and insulation than the white bead foam. It would take a 2" thick piece of white bead foam to match Dow's superior characteristics with a 1 ½" thickness. Few people are aware that white bead foam will "absorb" moisture, while the Blue Dow will not. The white bead foam actually gains weight with time."

Again, they are comparing the blue foam to white bead foam, not fiberglass insulation here. It also appears to me that they mix up strength, moisture barrier qualities and insulation in an attempt to "spin" the answer in their favor. I think the blue foam may be stronger, and a superior moisture barrier but I still can't see where it is superior insulation.

This is a great discussion.

ChiefJohn · 07-28-2007, 04:16 AM

This discussion is above me -- I did find a source that compares the various types of insulation here.

John

MaryJane Svenson · 07-28-2007, 04:36 AM

I too am enjoying this discussion. I always was under the impression that the solid insulation material was best - higher R value - but also would continue to insulate if wet. I also understood that fiberglass compacts and loses its insulating properties when wet (to say nothing of staying wet and growing mold) Would like to know if that is true and what happens when your trialer springs a leak like the one discussed in the shower?

MaryJane Svenson · 07-28-2007, 09:18 AM

My husband wants to know why the rv industry doesn't use the blow in foam - which he feels has the highest r value. Also shows it does on the chart - great resource thanks Chiefjohn
Any ideas on that one? That would really seal up all the cracks and crevices!

D and J · 07-28-2007, 11:12 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MaryJane Svenson:
My husband wants to know why the rv industry doesn't use the blow in foam - which he feels has the highest r value. Also shows it does on the chart - great resource thanks Chiefjohn
Any ideas on that one? That would really seal up all the cracks and crevices! </div></BLOCKQUOTE>

I could be wrong, but I think it is not used because it can breakdown due to movement and stress cause by a chassis rolling down the highway. About 25 years ago, I owned a Chevy C20 van that I installed paneling on the inside. After the paneling was installed, I drilled some small holes, and injected blow in foam between the paneling and the sheet metal. Worked great till about a year, then the screaching noise from the foam started to drive me crazy.

24him · 07-28-2007, 12:22 PM

ok, let's see how the fiberglass stacks up with foam. 1( foam is toxic ,right ?
2 ( fiberglass is not ? right ?
3 Lord forbid, that you have a fire, with the foam you will breath the toxic before you know it. with the fiberglass seems to me that your safer less or no toxic fumes.
personal i was told by a fireman to stay away from the foam, no matter how much " R " value it has. the toxic fumes will KILL YOU before you have a chance to get out!!
so it's your call ! as for me i will stay with fiberglass..
24him

camperguy · 07-28-2007, 12:49 PM

Mary Jane..I assume you are asking why the RV industry doesn't use polyurethane. It would be very expensive and labor intensive to install. It gets sprayed into the wall, then it expands for a few seconds, and sets up. It would be very difficult to spray it evenly into a 1 1/2" cavity. We used it in our new office, but we had 5 1/2" studs to work with. It's a great insulator, seals up every crevice and is extremely quiet from the outside world! However, I don't think it would work in an RV.