Hung wall vs. Vacubond wall

[mojoracing]

When thinking about purchasing a new coach, I am not able to come to a common sense decision as to which method of wall construction is better as far as quality of construction and which one will hold up better over time. I guess a good way to compare the two types is by comparing two brands of coachs. Newmar builds a hung wall very much similar to the way one would build a wall in a residential house with wood studs while Entegra builds a vacubonded wall that is an aluminum frame with insulation, glued and sandwiched together using a vacuum bag or table. Besides having to decide which is better and will hold up longer, there is what I believe to be a cosmetic difference on the outside of the coach. When building a hung wall, I believe they use a thicker fiberglass outer layer that doesnt show ripples and deformities as much as a vacubonded wall does thereby giving a much smoother wall and better looking paint. If you were able to choose either wall structure regardless of coach, which would you choose? Again just wall design not coach builder.

[Mr_D]

Actually the hung wall will show more ripples. Having had two Dutch Stars with hung wall construction and now CC with a vacuum bonded wall I guess I'd have to say: I'm not sure!
I think it comes down to how well they fit the insulation and get the openings sealed. Our CC shows some of the steel ribs and stringers, just like our Dutch Stars did. Both are insulated to about the same R values too. The one thing we notice is that the fiberglass roof in the Magna lets more rain sound through than the BriteTek roof on the DSDP.

[JMonroe]

The only wood in the Newmar construction is in the floor. The wall studs are aluminum, just like Entegra.

Builders of both types will be able to list advantages. I like Newmar's ability to run wires through the exterior walls, just as in a home. Outlets in our current coach, and in most RVs, are installed in/on cabinets, many times sticking out an inch or two from the mounting surface. I don't know how or where Entegra mounts its outlets. Watching Newmar's informational videos they also claim the hung wall offers greater flexibility, fewer cracks. A sales rep trying to sell us on a Tiffin bus was pounding on the exterior walls demonstrating how rigid the Tiffin was. One thing very important to me was no wood/Masonite paneling used in the exterior wall. That's a certain delamination waiting to happen, at sometime over the life cycle of the RV.

In a perfect world I'd like to see the stud wall and once wired sprayed insulation. Now that would be tight.

Bottom line, there are a lot of nice Newmar, Tiffin and Entegra coaches on the road with many years and miles on them (although Entegra doesn't have the long history of the others). Searching past threads for any potential problems you're concerned about may lead you to one brand over another. In the end, there's no perfect RV, and if there was, few of us would be able to afford it.

[mojoracing]

Im just worried about delamination and structural integrity. I love the newmars but seem to remember hearing about delam. Do any of the three you mentioned use luan or plywood in their walls sandwiched in somewhere?

[gtsum2]

I looked at newmar next to sportscoach, winny, and fleet wood discovery and looking down the side, the newmar looked much smoother. Could not see any of the studs in the wall...I could see them (sun was hitting all of them at an angle just right) on all the others. Granted these weren't entegra or tiffin quality coaches, but the difference to me was striking

[Mr_D]

Originally Posted by mojoracing

Im just worried about delamination and structural integrity. I love the newmars but seem to remember hearing about delam. Do any of the three you mentioned use luan or plywood in their walls sandwiched in somewhere?

Newmar doesn't and they're not laminated so they can't delaminate. That's the beauty of hung wall.

Our CC used steel frame construction, foam insulation cut to fit the wall openings and then the outside is vacuum bonded. Very heavy and solid but could still delaminate I'm told.

[JMonroe]

As Mr D says, the Newmars are not laminated in the first place, so delamination is a non issue. You can find links to construction videos on the Newmar web site that show them gluing the outer skin to the otherwise completed wall.

[Gary RVRoamer]

If the skin is glued on (and it is), it can delaminate. That's all delamination is, adhesive that no longer holds the skin to the structure. If water gets in, it is probably going to come apart. If not, no worries.

[MRUSA14]

Originally Posted by JMonroe

Bottom line, there are a lot of nice Newmar, Tiffin and Entegra coaches on the road with many years and miles on them (although Entegra doesn't have the long history of the others).

Actually, Entegra bought the assets of Travel Supreme, who began making Fifth Wheels in the 90's and Class A's in 2001. They've been building them the same way for over 15 years. Travel Supreme was founded by ex-Newmar employees, and they basically copied the procedure that Newmar used. I have been through tours at both factories and I doubt that there is much difference in the wall construction of these two brands.

[loisjop]

i don't know where the op got his information, but it is not correct as far as ENTEGRA is concerned. They do not have vaccubond walls. Their walls are all hung walls which allows the access to the wall after installation to run wiring, insulate, and probably most important to run carriage bolts through bottom of wall, through floor and into frame of Mh. Makes a much stronger construction than running screws up from the bottom which is your only choice if you have a vaccubond wall. The hung walls do not delaminate. I suppose they could come unglued from the aluminum studs, but I've never heard of that happening.
By the way having a hung wall allows ENTEGRA to place wall studs 16 inches on center same as a house.
People need to get their facts straight before they start putting out erroneous info.
Yes, the fiberglass ENTEGRA uses is much heavier than in a bonded wall.

[Scarab0088]

Originally Posted by JMonroe

The only wood in the Newmar construction is in the floor. The wall studs are aluminum, just like Entegra...

Originally Posted by Mr_D

Newmar doesn't and they're not laminated so they can't delaminate...

Please notice...there IS wood and lamination used in the Newmar's exterior walls.

The finished fiberglass exterior on all (at least current) Newmar lines is glued to a 3/16 plywood...been that way since we have looked/shopped...


See their product drawing here.
http://www.newmarcorp.com/motor-coac...pecifications/
And
Dutch Star motor coach specs | Newmar
And other model lines...Click on the drawing to enlarge.

IMHO, this makes the exterior walls of a bonded or hung wall virtually equal for delam. risk.
Therefore our focus was insulation. Batten will sag over time, closed cell foam will not.
Plus, if the insulation is bonded to the exterior wall as well as the interior surfaces, all the better.

The Brand X vs. Brand Y argument...leave us out of that.

Safe travels

[skypilot_1]

And Newmar uses fiberglass batten insulation (pink stuff) in a 2.3 inch thick wall, floor and ceilings.
The thermopane windows have a higher R factor. I prefer closed cell foam in my 2 inch thick walls. Jus sayn

[skypilot_1]

Originally Posted by JMonroe

As Mr D says, the Newmars are not laminated in the first place, so delamination is a non issue. You can find links to construction videos on the Newmar web site that show them gluing the outer skin to the otherwise completed wall.

WRONG, seen too many to buy that.

[skypilot_1]

The delam problem came about when the EPA mandated the RV adhesive be water based, unlike the aircraft industry.