Insulation

[toypusher]

I have high (very high) hopes to get to work on the Cubby starting tomorrow. Anyway, I have thinking about using the 'foil-bubble-foil' or FBF insulation in my teardrop. Here's the plan: use 1/2" ridgid insulation and a layer of FBF in the sidewalls. It's the roof the causes me some concern, as the plans have the aluminum skin put directly over the insulation with only the spars as additional support. It is supposed to be 1 layer of 3/4" and 1 layer of 1/2" ridgid stuff. I am thinking of 1layer of 3/4" and two layers of the FBF. Does anyone think that the support will be there for the outer skin if the FBF layers are to the outside (or top)? Should I put the FBF in the sidewalls on the outside or the inside of the ridgid stuff? Or is a single layer and an airspace a better idea? Not sure about any of this, but I really like the idea of the FBF due to it's extra 'R' value.

Kerry

[Chris C]

I'm a firm believer...............and avid user of the foil/bubble/foil insulation and highly recommend it. Unless you just have to have the rigid insulation, I'd recommend not using it.

[rjhager]

Hi, Kerry,

I know you're using Kevin's plans (I did too) and that's why I used an exterior 1/8" skin on top. I live in a very hail-prone area and felt that it was needed to preclude denting from hail. If you add that top layer of ply, I certainly wouldn't worry about the insulation and use whatever you want.

My $.02 worth!

Good luck with the build and make sure you take plent of pix!

Randy

[toypusher]

Randy

I have considered putting a 1/8" on the top, but am not sure at this point and wanted to get some other opinions. We don't really get much hail around here and I did not want the extra work, weight, or expense if I do not need to go that route.

Thanks

Kerry

[TomS]

I'm putting a 3/8 flexable luan on the outside of my roof.

[Woody]

I would put something to support or back the aluminum roofing 1/8" or whatever. It would be ashame for a dent, ripple or a sag between spars to ruin a good look and cause additional expense later to repair or replace. Just the force of the air when towing could cause a problem with flexing. Let alone some road debris hitting the unbacked metal. I have a dent in the wood (mine is a woody) from a semi tire piece that some else kicked up and smacked the upper part of the front radius of the trailer and it is 1/4" luan backed with another 1/4"piece in that area.The blow was hard enough to dent and marginally crack the wood in the area about the size of a softball. It really could have done some real damage, if that particular area was thinner, it would have penetrated for sure. I could only imagine the damaged area if it wasn't backed and just thin aluminum metal. It would have been a massive and serious damage, if not a hole. So hail is not the only problem to consider here

[Chuck Craven]

I am gong to use the aluminum over the struts. No backing with wood. The aluminum will be .062” thick. Any thinner will show stress points and/or dents easier. My struts/spars will be 1”X1”X1/8” angle iron set at 12” centers. The tear will be 58” wide and 10 foot long. The sides are 1 ½” stress skin panels with a 2” insulated floor. The old Airstreams used .050” aluminum skin and was hard to dent, even at the curved ends. The newer ones use .032 or thinner and dent quite easy. The thicker the aluminum is the better! If you go thicker than .062” then it gets quite hard to work with. It’s all a tradeoff. I do not want to back the roof with wood and have to glue the aluminum. The only glue I have found that will stick to aluminum is T-88 but it is too expensive to get full glue up. And too much work to clean the aluminum.
Chuck

[Chris C]

Chuck, I don't know if you saw this thread or not. Pretty interesting.

http://tnttt.com/viewtopic.php?t=2866

[Chuck Craven]

Hi Chris!
Yes I have seen that thread. I have used the same type of this product on my custom van and after 15 years I had some of the carpet come loose. Recoated the spots and a another 15 years has gone by with some other spots coming loose. But after 30 years loose carpet is not to bad! I never tried it with aluminum but I think the heat from the sun will change its compassion. It will either get brittle or brake down in to goo, either way it has to loosen up. The aluminum I am getting is 60” wide and I will be bending the edges down over the sides. Then that will be covered it with a wood trim piece and caulk between the aluminum and the trim. If the caulk fails I can take off the trim and redo it. The tear will be a tin roof woody.
I have to take vacation the week of the Forth of July so I should have the trailer frame welded and panted. Ready for the body building process.
Chuck