Insulation in the walls.. November 07, 2011, 06:30:48 pm Yahoo Message Number: 126459So, with a few walls open, I've found the typical fiberglass insulation in place -- and while I could put it back where it came from I'm wondering about the merits of ditching the fiberglass insulation in favor of rigid foam board with or without a foil wrapping. I did see a fair amount of comments here on the LD mailing list about insulation and that new models from '08 and beyond use some sort of foam insulation instead of fiberglass. In thinking about the wall thickness, I believe I might be able to get almost 1.75" thick on our '85 to completely fill each wall void but I'm not likely going to find a material in the exact thickness which I think is about 1/16" thinner than 1.75" if I recall.. Has anyone done this sort of upgrade while your wall(s) was open and more importantly was there obvious benefits?In checking both Home Depot & Lowes I can get two sheets to make a foam sandwich for ~$20 as I'm sure I wouldn't need more than that. The added benefit of course is that if moisture gets in the wall cavity in the future, it won't soak into the foam like it does with fiberglass.So.. Whaddya think? Worth-it?
Re: Insulation in the walls.. Reply #1 – November 07, 2011, 06:46:24 pm Yahoo Message Number: 126460"So.. Whaddya think? Worth-it?"RickWhy not? I can't think of any downside. It is what the Factory, and just about everyone else, now uses. I see no reason to use the more expensive aluminum coated foam. Cut the foam so it is a press fit, with few or no edge gaps. A tight fit helps eliminate squeaks and air leaks.Do the rear corners of your LD have rot between the windows? This is common in older LDs that have not been well maintained.Larry
Re: Insulation in the walls.. Reply #2 – November 07, 2011, 06:47:59 pm Yahoo Message Number: 126461I watched a friend convert an Eagle bus into a motorhome. For wall insulation, they sprayed foam insulation on the inside (After all the wiring, etc. was finished.) When it was firm, they shaved it smooth before putting on the interior walls. That's about as good as it gets.Dick
Re: Insulation in the walls.. Reply #3 – November 07, 2011, 07:03:56 pm Yahoo Message Number: 126462On Tue, 08 Nov 2011 00:46:15 -0000, Larry wrote:Quote Why not? I can't think of any downside. It is what the Factory, and just about everyone else, now uses. I see no reason to use the more expensive aluminum coated foam. Cut the foam so it is a press fit, with few or no edge gaps. A tight fit helps eliminate squeaks and air leaks. Sounds good! I'll put that on my list of things to be 'adjusted'.. Quote Do the rear corners of your LD have rot between the windows? This is common in older LDs that have not been well maintained. Yup.. Checkout the pics at : http://old-lazydaze-rehab.blogspot.com/ Luckily the void down the false-wall (where the spare lives) looks like it's in good shape. I'll be applying a Boracare clone to the material I'm not removing in an effort to kill any remaining fungi I can't get to as this product will soak into the wood fibers and stabilize things prior to beefing up the bad parts of the wood structure using System3 products which will harden up the wood and allow me to re-mold parts with jagged ends and also allow screwing into them after they've cured. I'll also be replacing the entire bottom sill plate of the back window with new wood (ripped down kiln dried 2x3's) to fit the wall cavity to provide better structure than just fixing the left/right corners of that back window -- the center was in fine shape. I believe I've got my gameplan figured out on this part of the project. Just gotta run to the mothership to get some corner gimp and some spiral nails and I'm good to go..-- Rick
Re: Insulation in the walls.. Reply #4 – November 07, 2011, 09:34:21 pm Yahoo Message Number: 126465And for small sections a few feet square, you might be able to use the expanding foam dispensers they sell at Home Depot and other places. One or two cans would be plenty; also, it might even be easier to install the inside wall, then just squirt the foam into the wall through a couple small, well-placed holes.Eric
Re: Insulation in the walls.. Reply #5 – November 07, 2011, 11:07:05 pm Yahoo Message Number: 126466On Nov 7, 2011, at 7:34 PM, Eric Greenwell wrote:QuoteAnd for small sections a few feet square, you might be able to use the expanding foam dispensers they sell at Home Depot and other places. One or two cans would be plenty; also, it might even be easier to install the inside wall, then just squirt the foam into the wall through a couple small, well-placed holes. I'll stick with the solid foam -- I've not had great results 'sculpting' that spray foam once it's done expanding.. Thanks for the idea though![Non-text portions of this message have been removed]
Re: Insulation in the walls.. Reply #6 – November 08, 2011, 01:37:18 am Yahoo Message Number: 126470"And for small sections a few feet square, you might be able to use the expanding foam dispensers they sell at Home Depot and other places." If doing this, make sure to use the 'low-expansion' type foam and not the regular foam, also known as 'window and door' foam. A little too much of the regular foam can pop the paneling off the wall, even if glued. The stuff is amazingly powerful, a useful bit of knowledge gained from a couple of messy personal experiences. http://greatstuff.dow.com/>Larry
Re: Insulation in the walls.. Reply #7 – November 08, 2011, 08:40:10 am Yahoo Message Number: 126471Rick raised the subject of foam insulation in the walls. Here is what I know based on the housing industry rather than RV's.1) Open cell foam insulation, in boards or sprayed in place, has about the same insulation value as classic fiberglass.2) Closed cell foam, sprayed in place, has about twice the insulation value of open cell foam and fiberglass.3) Closed cell foam forms its own vapor barrier.4) Both open cell and closed cell sprayed foam will require professional installation for the best job. The void must be completely filled for best results, which means some overfill will happen. This gets trimmed using a device that shaves the surface.5) On a personal note, thirty years ago I made my own camper in a bare Tradesman van. After running the wires, etc, I had closed cell foam sprayed in place. The result was an amazing increase in wall strength. You know how you can knock on a hollow wall panel of sheet metal and you get a sound that lets you know it is hollow, and how such panels have some give to them? Well, knocking on one of my panels produced a dull thud, much like knocking on a stone wall. The panels had no give to them. Fifteen years later, parts of the van that did not have foam fill behind them were rusting out (thank you, NJ winters and salty roads) but the areas with the foam were completely free of rust and any sign of aging, except for some chalking of the paint.6) Solid foam panels are pretty good, if you can get them snugly in the space to be filled. One way is to use Liquid Nails to bond the panel in place, then use the spray foam in cans (low expansion, please) to go around the edges and fill any spaces.7) If you use foam panels, find out if the panels are open or closed cell foam. If open cell, a vapor barrier is needed. A sheet of poly stapled in place will do nicely. Once in place, if you ever have to gain access to the space, foam boards make that much easier than sprayed in place foam.I am a fan of sprayed in place closed cell foam. There is something new out there that trumps it, however - gas-filled panels. See http://tinyurl.com/cs5ktmc. They have twice the insulation value as closed cell foam, or 4 times that of open cell foam or fiberglass. They are very light. They are easy to install, remove and reinstall in spaces of standard or uniform dimension. This is the stuff of the future, folks.Ken F in NM[Non-text portions of this message have been removed]
Re: Insulation in the walls.. Reply #8 – November 08, 2011, 09:37:06 am Yahoo Message Number: 126474Interesting stuff, Ken. I can see it used both
Re: Insulation in the walls.. Reply #9 – November 08, 2011, 10:32:20 am Yahoo Message Number: 126476On Tue, 08 Nov 2011 15:37:05 -0000, sunnyeddie2000 wrote: QuoteInteresting stuff, Ken. I can see it used both in the motorhome and in a house, depending on cost. Be sure there is no period included when you click on the link, like I did the first time. my only negative thought on that product -- particularly if used in a house is what happens if the homeowner decides to hang a picture or something and drives a fastener into the wall and accidentally punctures the inflated panel -- perhaps if they're only 1.5" thick then they'd be somehow centered within the stud space so issues like that would be minimized. Otherwise it sounds like a great product -- albeit you need to have very standardized sizes since it's a sealed product like a bag..
Re: Insulation in the walls.. Reply #10 – November 08, 2011, 12:06:26 pm Yahoo Message Number: 126477"I am a fan of sprayed in place closed cell foam. There is something new out there that trumps it, however - gas-filled panels."Ken If I ever build another house, it will have sprayed foam insulation, after it is completely framed, wired, plumbed and raceways installed to accommodate future wiring and plumbing changes and additions. Once the foam is sprayed, the walls are permanently sealed, which is good in that every little crack and crevice is tightly sealed, almost completely blocking infiltration. Fine Homebuilding recently had a article on how they sealed a new home, under construction, to a point there there was almost no infiltration. Homes this tight need air-to-air heat exchangers to provide enough fresh air for a healthy environment. LD could build an extremely solid RV by spraying the walls, after interior construction and before the exterior panels are installed. Heck, enough foam and it might float...always wanted a yacht. Gas bag insulation, hmmm, very lightweight but not too sure I would be eager to use them since it is a new product, without a long track record. I have never seen a balloon stay inflated for more than a few weeks before either leaking down or popping. If the tubes do develop leaks or get damaged (Rick's nail in the wall), there would be no insulation and no easy way to reinflate, repair or replaced the tubes. Since the price is right up there with spray insulation, a proven product, foam would seem to be a more logical choice plus it has so many extra benefits such a low noise, added structural strength and the great advantage of a totally sealed structure. Gas insulation is still new and will probably go through many evolutionary changes below it is ready for prime time. I have watched workers at LD install foam board to LDs under construction. They cut the foam so that it is slightly bigger than the space it is intended to fit and is then forced into place, using the foam's ability to compress, to hold it without the use of glue or sealant You can go only so far insulating an LD. The walls are thin and do not allow much insulation, no matter what type is used. The large windows, even if dual-paned, are huge heat leaks plus their aluminum frames transfer a lot of heat and cold. The entire cab, frame and exterior skin of the coach are metal which is also a great conductor of heat. My latest fantasy is to access an industrial size 3D plastic printer and 'print' a new coach, made of various plastics picked for the application. The newer machines can blend different colors and types of plastic. With a CAD-CAM approach, a whole new world of RVs could be possible. http://en.wikipedia.org/wiki/3D_printing> http://www.popsci.com/technology/article/2010-04/hp-prints-three-dimensions-release-designjet-3d>Larry
Re: Insulation in the walls.. Reply #11 – November 08, 2011, 01:48:31 pm Yahoo Message Number: 126478Good catch Eddie. I didn't see that period, and thought it was a bad address.Dick
Re: Insulation in the walls.. Reply #12 – November 09, 2011, 07:50:58 am Yahoo Message Number: 126497RE: Gas-filled panels, second thoughts. Something occurred to me after my post in which I introduced gas-filled panels. So far they are being used in open spaces like attics. I visualized them being placed in a tightly enclosed wall such as on a LD, at approximately sea level at the factory, then the coach being driven to 8,000 or 10,000 feet elevation. The gas expands, either rupturing the panel or the wall, or leaking the special fill gases out. You drop back to lower altitudes, assuming your walls still appear to be intact, and the panels compress, reducing their value as an insulator.... The panels may be great for stick houses, but I don't think they would work on a structure that changes location like we do.Ken F in NM
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