Replacement Insulation

[59toaster]

Originally Posted by Janet

"Stealth Post"This is really Gary. I found 4 Wasp nests and a lot of Black Widow egg sacs. All clean now. Ya, the insulation they used is for the birds or Wasps or what ever. I'm going to use the spray foam to do away with all that.

I need to post the picture of the 2ft x 2ft yepp jacket nest we had in ours.

I was about to post about soem of these concers as I am getting ready to start hussling on ours again. While I was replacing our floor las fal I bough enough 3.5 in batts of ifiberglass insulation to do the floor. At the last minute I decided I did not want it between the frame and floor. I had found severa areas where the insulation had held water and caused some frame rust.

I live in mild climate and have seriously thought about not installing any insulation to the floor. It was so horrid to deal with when we had to dissassemble the coach. Then a second thought was 2 inch blue board tacked to the floor. Again if the coache leaked this would keep the water against the wood if I didn't alwo a little airspace.

Now the spray in being water proof and the fact that I have put a epoxy coat on the wood Hmmmm this has potential.

John:
Tell me more about this stuff in the walls? I have been concidering this as well. With it being closed cell I was wondering if it would seal any minor leaks I may have but it raised a concern of if the water got between say a rib and the shell and was traped would it cause corrosion to form?

I know smebody else on here mentioned using it and not only did it work great as insulation but they said it did a great job with noise insulation. There is a simular product used in the automotive industry and it is used for both noise and structural. It adds rigitity to Uni body vehicles and reduces flex a conciderable amount. Not the formula is a little different and what they use is a bit more rigid but I bet there would still be some improvements here.

Now the down side is the cost. To do the whole inside in 1.5 inches would be quite expensive. Somewhere has to have the stuff cheaper. Grainger is expensive if you don't have a comercial acct with them. I had a guy cut me a break on some stuff by marking them a comercial acct and it was almost a 35% discount.

[Ken J]

On my past two trailers and on the 58 I'm restoring I have not put any insulation in the belly. My thinking is all it does in soak and hold water. I figure that since most SOB's don't have any belly - or insulation - I don't need it either. I live in cold country and last summer we were camping in Texas a 105 degrees, and here in Colorado we have been down to 10 degrees and so I don't miss it at all.

I want the belly to breathe - water will get in there on the road and I want it to dry out quickly.

Just some thoughts to consider

Ken

[Janets Husband]

Originally Posted by Ken J

On my past two trailers and on the 58 I'm restoring I have not put any insulation in the belly. My thinking is all it does in soak and hold water. I figure that since most SOB's don't have any belly - or insulation - I don't need it either. I live in cold country and last summer we were camping in Texas a 105 degrees, and here in Colorado we have been down to 10 degrees and so I don't miss it at all.

I want the belly to breathe - water will get in there on the road and I want it to dry out quickly.

Just some thoughts to consider

Ken

Ken
The foam I used is a closed cell foam it can't suck up water. One of the uses they have for the foam is for flotation in boats and docks.
I really don't know about the breathing thing but it is used in house walls and it does not appear to be a problem in that use.
Water picked up from road spray... I'm not sure it would be a problem either. If the foam is sprayed correctly it will seal anything it touches.
As stated in an earlier post insulation value is not the only consideration for foam insulation. It works great to cut down on outside noise.
I guess only time will tell about how it will stand up to the riggers of travel.

[malconium]

I have recently purchased a 1973 31' Sovereign that was mostly gutted inside. One of the things I am pondering is whether or not I need to remove the walls to check wiring, etc. I am also interested in installing better insulation if possible. Of course that would be easy enough to do if I do in fact remove the wall panels. I was thinking about what I could do to improve the wall insulation if I decided I did not need to remove the wall panels for any other reason. I am aware that foam insulation is used in residentual uses for adding insulation to older homes. The Fomo Foam website in fact has a slow rise foam that they say can be used for installing in walls through a 1/2" diameter hole. They also say that if there is existing fiberglass insulation in the wall that a 3/4" hole with a piece of plasting tubing can be used to make sure the foam starts in the bottom of the cavity. So here are some questions:

1. Has anyone out there added foam to their walls without removing the skin?
2. Is this approach likely to work or is it a dumb idea for any reason?
3. Any suggestions on how to tell where all the cross members are to be sure that I filled all the cavities?
4. Does anyone have any ideas on how to invisibly patch 1/2" or 3/4" holes in the walls if I do not overlay them with something else (such as wood)?
5. Does anyone have any thoughts on using the same approach to insulate the floor (namely to fill the entire floor with foam through holes in the subfloor with the belly pan in place)?

[j54mark]

malconium,

I can't answer all your questions, but I can take on a few of them.

1. Do not remove the interior panels without properly supporting the coach from underneath. They are part of the monocoque structure and their removal - or even a few of them - will cause the structure to sag. You will notice this when you go to reinstall and the rivet holes don't line up.

2. There is no way to get effective coverage on the interior cavities by pumping in foam. The existing fiberglass, the stringers, and an amazing amount of wiring will make complete coverage impossible. You can spot the cross pieces by the rivet lines.

3. Foam-in-place for the floor from above is an even worse idea, if possible. It might be possible from underneath, by cutting holes in the belly pan, I don't know. They would be easy to patch and the belly pan is not structural, as the floor is.

Mark

[Rick Alston]

59Toaster said "Then a second thought was 2 inch blue board tacked to the floor. Again if the coache leaked this would keep the water against the wood if I didn't alwo a little airspace."
I am thinking of doing this process and my thought is to apply the blue-board insulation but leave an inch or so around the edges to handle the water that may come down the side walls. Also, I think placing a vapor barrier between the wood floor and the blue-board would be helpful to keep any road spray off the wood.
Any thoughts?

[Over59]

Rich. Why not glue the blue board to the underside of the floor leaving no space for the water vapor. Seal around the floor / insulation edge with a flexible waterproof caulking and leaving space around the steel which is painted with POR 15 first and sealed anyway. Alternative to consider is fiberglass foiled sheeting between the floor and blue board leaving the edges open for "breathing". Wouldn't it be easier to seal the underside of the floor with a waterproof paint? If the top and bottom are sealed then the only access water has is the edges with water getting in from around the trim ( seal it with the gray stuff) or down the wall cavity from shell leaks ( my favorite thing to worry about). I don't think breathing is going to help that. I believe that if you sit the trailer in the sun and get the shell heated up good that the moisture will build vapor pressure and find it's way inside the coach and out the fan vent.
I agree with the guy who wanted plastic floors and drain holes between the shells.
If it cann't rot it cann't rot. Seems airstream materials engineers lost their way somewhere in the 70's.

[74Argosy24MH]

Originally Posted by 59toaster

John:
Tell me more about this stuff in the walls? I have been concidering this as well. With it being closed cell I was wondering if it would seal any minor leaks I may have but it raised a concern of if the water got between say a rib and the shell and was traped would it cause corrosion to form?

Sorry Toaster, I missed your post the first time around.

I got mine from Fastenal, you live near Atlanta, there are outlets there. It is expensive but they were cheaper than the manufacturer's vendors. It is pressurized also so must be shipped as hazardous material which adds to the cost.

One thing I learned is that there is a flame retardant version. RVs burn quickly, flammable foam (and the vapors) inside the walls are something I didn't want. Another thing I learned was to check the dates on the cylinders, I got one that only had 2 days to go and sent it back. They weren't happy, but it aint cheap and I didn't want to deal with having a mess because they didn't rotate stock.

Your point about leaks is something I considered. You are right if it leaks water will probably be there forever. I did a lot of work on the exterior of mine, all windows and doors were pulled and resealed with butyl rubber tape, there is no sealer around the outside and no leaks. The lapped seams of the outer skins probably never leak, mine have between 4 and 6 inches of overlap. Vents, plumbing vents, lights, etc. I firmly believe should be (pulled and) resealed as part of a routine maintence schedule. So in the long run I figured leaks were not going to be as much a problem as with fiberglass.

This was not advertised as sound insulation, specifically on their website (before Dow took over) it said there were no sound insulating qualities. I was used to working in an empty hollow shell so that might have made a difference. But the skin is more solid and it is much quieter after insulating. I dould definitely do it again.

FWIW- I put a Fantastic fan in a 1990 Holiday Rambler mh last week. They are constructed somewhat similar to an AS, aluminum skin rivited to an aluminum frame, but wood paneling inside. It had 2" styrofoam insulation in the ceiling and 1/2" styrofoam glued to the paneling. There has been some discussion here about styrofoam falling apart, but when I pulled the old vent there wasn't any, no little pile of styrofoam balls drifting to the floor. I pulled the ceiling panel down a little and it looked good for 14 years old. I am sure it was fitted to the openings and being glued to the paneling helped, but with proper installation it seems to work.

John

[Rick Alston]

Your comment on insulation is right on target!

Yes, I think it may be a good idea to seal the outside edges and paint the exposed wood with a sealant. Leaving a small gap for the steel to breathe is also a key procedure to avoid moisture building up on the frame and subsequent rust.

About your comment on Airstream engineers, I'd like to make an observation. In 1975, I invited Bill Hewlett of Hewlett-Packard to speak at a business club at the university, and he came and was very "entertaining" to us as senior business majors. At lunch, he told me that H-P hand-held scientific calculators were built with obsolescence in the design. This was purposeful, he said, because no company could continue in business without providing customer support and repair service for existing products along with building new and better products. I think the survival of H-P is a clear indication of Bill's business mind.

So, Airstream probably thinks in a similar vain. If Airstream built trailers or motor homes to last "a lifetime", then a good part of its profits from new sales and repair would not happen; thus its survival as a going concern could be questionable.

Thanks for your thoughts.
Rick

[Silverflames]

My 1969 Ambassador has spray foam underneath it. Did a great job of holding the moisture around the frame. I just finished replacing the whole front of the frame from the front door forward. I will not be going with the spray foam again... Foam board maybe?? Plus when you try to cut it away, it gets in your eyes and hurts like hell!!