Aluminum AND luan for outer roof? or just aluminum?

[misterW]

What to most people put over their cross members for the outer roof? Just aluminum? or aluminum over a second layer of luan (the first layer being under the cross members for the inner ceiling)?

I had planned on just using aluminum, but I may end up using thinner aluminum than planned (.040" instead of .060") and was worried about denting if someone leaned against the trailer?

Ideas or suggestions?

[tonyj]

Most use an outer layer of luan or birch under the aluminum. It helps to have that layer of support so the outer metal skin doesn't look quite so beat up. That said, a projectile of any sort will still leave a mark or dent.

[madjack]

I used no underlayment, just apply the AL directly over the spars...you should use a .040 thick or better if doing this...I did this after consulting the fine folks at Camp-Inn...this is how they build their top shelf teardrops...you will havvta apply an underlayment for the hatch...I used 1/8th birch for this(single layer).....................
madjack

p.s. I have had no problems with dents and ripples doing this...just the normal rock dings you will get regardless of what you do...........MJ

[ssrjim]

I've done both and I don't think it much matters.

Just do what you want.

[gregp136]

No luan here, just insulation. No problems so far.

Greg (and Laurie)

[Kevin & Sandy]

I used thin plywood underneath the aluminum, but then again my aluminum was .032.

[kennyrayandersen]

I used thin plywood underneath the aluminum, but then again my aluminum was .032.

Probably a good call!
I’ve even thought of bonding .025 Al to a core (with maybe fiberglass fabric on the inside), but you’d have to make some tooling, which thing takes a lot of time and effort, not to mention extra dollars. The spar way is easier for on-off builds for sure.

[planovet]

I used 1/8" birch ply under my .040 aluminum roof. It's pretty solid. But like others have said, it probably doesn't matter unless you are crawling around on top of the roof.