Advice needs about roofing an RV I am considering.

[Mike Conte]

Advice needed!!

Hi. I am considering a 1975 Midas Mini 260 (GMC 350 cu. In.) that was pampered by the owner (a skillful mechanic) for 35 yrs.  But the gentleman passed away before he could finish replacing the roof after it was hit by a tree. He almost finished framing (2x3's laid flat) and bought a roll of aluminum. If I buy it should I...

1: try to finish it myself or hire a body shop that does a lot of RV work.

2: Does the aluminum need a plywood sub-deck? I have read "no" but I can't imagine it is strong enough. From my research it seems the aluminum and 3/8 plywood will weigh about 300 lbs each.

3: Should I go with plywood and a rubber membrane and sell the aluminum (or maybe save it and dream of building a teardrop).

 Also, I think the roof should be usable to carry (for example) a small boat (mine is about 65lbs) or other cargo. I am probably just a newbie who thinks he needs more space. The boat is not that important.Please comment. 

It will be my first RV and we will be retired empty-nesters wandering the US and Canada visiting far-flung friends.

Thanks,

Mike354

[Rich Thomas]

It's hard to give you advice on the roof without knowing what you are up against. Most roofs do have a plywood sub structure under the aluminum. There are several good examples of roof repair in the links at the top and bottom of each page. Try looking through those and also if you can add some detailed pictures would help those members with the experience to better comment on your project. If you have carpentry skills or if you like to jump into new things you should have no or little problem doing the work yourself. Just don't let the project over whelm you.   

[Mike Conte]

Thank you Rich.  All but the last 4 feet of roof is completely removed and he put in the 2X3 joists.  The walls are good. I just can't see how the aluminum would be strong enough to walk on and I assume an RV roof should be able to handle that. I have researched quite a few roof repair postings but this is basically new construction.  I am sure the roof would have been perfect if he had finished it and I wish I new what plans he had for framing (ie. blocking between the joists etc. I think his plan was to put the seamless sheet of aluminum directly on the 2X3's).  I also wonder if the metal can be attached without using any screws, just an adhesive.  Thanks again. I think I will call the company that sells the aluminum.

[Jim Stoltz]

IMO, the aluminum will need a plywood base if you're going to want to put stuff up there. I would use the aluminum rather than going rubber since you would have it in-hand. You might be able to google the roof carrying capacity, assuming the previous owner was rebuilding it to factory specs. You can coat the whole new roof, or just the seams and protrusions with an EPDM coating. My old Allegro has an aluminum roof and I used about half-a-gallon of EPDM coating (Liquid Roof brand, but Dicor makes one too) on the seams, vents, plumbing stacks, etc. It works well.

[Rich Thomas]

Thanks for jumping in here Jim , I hope some of the others will as well. I think Mike needs some of you that have done this to chime in. Things like what ply to use as in 3 ply 5 ply what to attach it with and so on. 

[Jim Stoltz]

There are pics of my brothers pre-inferno repairs here somewhere. He used a table saw to rip 2x4s down to whatever wacky size the factory ceiling joists were. New plywood and then the original aluminum back over top. Sealed it with Liquid Roof EPDM sealant. Worked great but didn't hold up to the fire too well.

[david craft]

if he got the .040 aluminum then your good with out the plywood. it would be good to sheet ply the ac support and the deck for cargo though, also the antenna. glue on aluminum seems to promote electrolysis, dont use. seen this done at the factory back in the day. attach one end of the sheet at the termination at one end of the coach and the make a clamp of 1x2s and c clamps at the other. pull the entire sheet taut over the coach with a come along down over the radius at the end of the coach. when all is square, trim edges on sides and hammer over with a rubber mallet and staple. the factory had scaffolding and this went pretty fast and was entertaining to watch...lol...all done at a brisk walk! hammer the metal over just a little more each trip. attaching molding on the sides makes for a better sealing/draining roof. good luck! otherwise id sheet with 7/16 osb and epdm. do the entire roof for nascar events...be sure to chamfer the edges on the side of the wall of either roof before applying metal or rubber.

[david craft]

can we get a look at what you got? are you going for that original appearance or performance? the roof i depicted is square cornered, not the radiused pictured by pat. i probably would have epdm sheeted that over those radiused corners to be rid of the T bar down the roof and to prevent collecting water.

[Mike Conte]

Thank you all for responding. It is a typical Class C on a GMC vandura..I am going to take a closer look with a good light and take photos tomorrow.  I will also measure the thickness of the Aluminum.

Jim's pictures were good. Thanks again.

David: If I understand your process (or even if I don't, you sparked an idea. 

The aluminum is about 10 inches wider than the roof. I am thinking (not worried about the original look) that I pull the sheet over, square it up and fix it securely at the front under the cabover. Then I pull it tight with a come-along attached to the back end of the sheet. Then I would take it a few inches over the rear end and down the back wall.and secure it there. 

Then, instead of trimming it down each side, could I bend the overhanging metal over the top of the walls and secure it to the sides??  I would have all fasteners into vertical wall studs or on the bottom of the cabover.

(There is no A/C,just a crank open vent/fan)

Am I out to lunch and daydreaming here or might this work?  Not sure about how to bend down the 5" on each side but it sounds like a rubber mallet will do. I am not even sure that I'd need the metal trim. 

I have talked to a local shop and they estimate $1,000 labor.  So now, thanks to all of you, I am thinking about doing it myself as I described.  Please, stop me if I am crazy and getting myself into a mess I will regret.

[david craft]

thats prolly going to look like shittaki souffle. its a lot to snip granted, but just leave enough to cover with molding. theresmwood in the corner to attach to. who knows whats there 5" down. leave enough metal to hammer down to the screw line and staple. youll be glad u did...

[Mike Conte]

Yes, thanks David.  First I will look into the wall construction as I would want to be able to screw into solid studs, If that works out. I might add trim to match the stripe that runs end to end at mid-door level.  I wonder why they do not wrap the roof covering over the edge and down the side wall.

What type of staples?

I assume all metal fasteners have to be aluminum or at least, not steel.

BTW, you've probably accurately described the eventual artistic merit of my plan coupled with my skill ( or lack thereof).  I will probably need to name the unit, "Sandford and Son". (Hope you get the reference.)

I will report back after I see the rig again later today.

[Rich Thomas]

Mike, you can pick up an air nibbler or electric metal shear for a very reasonable price from Harbor Freight or the big box hardware stores. this will put you in a more confident situation. Stretch out the aluminum as you described and fit it to one side, then you only have to trim on the opposite side. also you can pick up metal clamps like vice grips to aid in bending called a hand brake. You can do this job and do it well for far less than your labor quote. good luck with your project.  

[david craft]

rich is pretty much right on.  with a lot of overhang, its get harder to get the cut right where you want it.  after the cut, if you work it a little at a time to get the full break, it wont stretch between areas you break and leave dimples.  you want one full break ideally.  does that make sense?  the break leaves a clean roof for drainage but also a clean side, without all the distortion you would have by continuing another 5 inches.