Underlayment for skins (?)

[les45]

(I posted this in the Canned Ham section but I'm posting it here also to see if anyone else might have some comments.)

I'm finally to the point of being ready to skin my pop-up to retro project (http://tnttt.com/viewtopic.php?f=50&t=70991). Picked a metal vendor and ordered the skins this week and hope to have them delivered in about two weeks. My plan had been to use the 5mm Revolutionply as an underlayment for all my wall skins but as I look through the canned ham restoration Youtube videos it looks like most people just staple their skins directly to the insulated wood framing without underlayment. I figure the underlayment will add about 80 lbs to the build so I'm not worried about the weight. I already have the plywood that I salvaged from a previous project. Any thoughts on the pros and cons of this issue?

[steve cowan]

I've followed your build journal and it is looking great.Nice and simple.If weight is no issue I would use the underlay.I think it would give more resistance to a dent
if trailer got whacked.Looks like you are close to the finish line.

[les45]

I've followed your build journal and it is looking great.Nice and simple.If weight is no issue I would use the underlay.I think it would give more resistance to a dent
if trailer got whacked.Looks like you are close to the finish line.

Thanks, Steve. I'm afraid it will be a while to finish. I'm traveling two weeks in May and then the summer heat will slow me down. We don't camp in the heat of the summer or the cold of winter so I'm not planning on a maiden cruise until Fall anyway. As for the underlayment, I'm leaning toward leaving it off since I'll have rigid foam insulation on all the walls. That should help with the dent issue. Also, my skins will have a corrugated pattern that keeps them fairly stiff also. One of the big factors is that it makes it a lot easier to install the metal skins when you can see where you are stapling and easier to measure to the holes for the clearance and running lights. I'll be using 16" panels which will have an effective face height of about 13" so I'll have a lot of stapling to do.