New here and have a few questions about replacing an aluminum roof ;)

[77 Spartan]

Hello everyone, I am new here and wanted to introduce myself and possibly meet some fellow RV’ers. We are from Arizona…dying in the heat!

I am hoping I can get some advice about replacing a continuous aluminum roof on a 1979 36’ 5th wheel.
The roof was flat, but over the years of what may be neglect or people walking on it, it has low and high spots in it. The spots range from 6" to possibly 8" difference in height. The roof was coated with some sort of sealer paint...doesn't look like rubber roofing, but none the less, it is a mess.

My question is, can I drill out all the rivets’ around the outer edge on the roof, remove the old roof, add in any new stringers' to help strengthen her up and then lay down, .040 4' x 8' aluminum sheets horizontally across the roof area instead of rolled aluminum roof?

I had in mind to start from the back laying the first sheet and then overlap the next sheet by a couple of inches with each sheet as I moved forward while adding some sort of sealer between them as they are overlapped. This way there would be no butt seams and less chance for any leaking.

Does this sound like a sound plan? The material is thicker than the rolled roofing I saw for 50.00 a running foot which would cost me 1500.00
If I use 4' x 8' .040 aluminum sheets, it will cost me around 600.00.

If my idea sounds good, then what would you recommend that I use to seal the outside of the overlapped aluminum panels and outside edges of the roof I pop rivet back together with? Rubber roofing?


I have searched everywhere and can see to find too much about aluminum roof replacement for trailers or 5th wheels. If anyone knows where i can find this information, please feel free to let me know where you found the information.


Thanks in advance!


Century

[mikelcan]

Normally more seams mean more places to leak. The plan of over lapping the seams back to front would help wind from driving from lifting the leading edge. But water will seek the easiest path to a lower elevation. That being said I would think that the eternal bond tape applied over each seam and at the penetration points (AC, skyligts, plumbing vents, etc) would prevent leaks and last a long time.

Mike

[SyrenSkywolf]

Like Mikelcan said, it would present more opportunities for leaking. If you go with that route, I also would recommend Eternabond tape. Two sided tape in between the overlaps, and 1 sided over the seams.

The toughest part about it is if you need to get up there, you could end up putting stress on the seams, eventually causing them to separate.

[Senior Chief]

Do you have evidence of prior leakage?

If not, I would not take the risk of removing your current roof. If your new roof does not seal properly, where do you start looking for the leak? Eternabond is amazing stuff, but its asking a lot to have 5 horizontal seams, plus caps and side seams to seal.

If you decide you still need a new roof, I would do the new aluminum, but then lay down a rubber membrane roof- they now have it as a DIY at the big box hardware stores.

[allegroman]

Heat is a problem, and during the day I feel a lot of it just by touching the ceiling inside, so the thought comes up: Possible to add a new roof above the old one, but including an inch or more insulation?

I don't leak, and this allegro has one-piece seamless aluminum roof. The frame seems to be 1" welded aluminum square tubing covered by 2 sheets of 3/4" plywood. Very strong and sound, but the heat comes thru quite well.

I have no idea what I'll do so far, but in your case, since you are redoing the metal anyhow, you might think about adding a bunch of good insulation while you are at it.

On the other hand, you could always completely remove it all down to the frame and start from scratch. That would reduce the added weight by putting up better stuff, rather than more stuff. Seamless is always good.

am

[ahicks]

The rafters are on 16" centers if I'm not mistaken. That means your 2" overlap on 48" sheets will require new spacing - which may or may not affect the ceiling panels/where they are installed with 48" butt joints?

I would do some more shopping for the rolled roofing. I think it's a much better plan. Is re-using what you have an option?

Have you established the reason for the low and high spots? Is there evidence of this also on the inside?

[77 Spartan]

Thanks so much for the replies. I think it might be best to post some images as there seem to be many of alternatives to what I may need to do.



I am attaching some images of the roof and what our new 5th wheel looks like.....I say our loosely because we will be picking it up this week once she goes through inspection to get a new VIN.



She is a 1978 32' Century Supreme 5th wheel.


I hope this may give everyone a good idea of what we are in for. I want to do an excellent job fixing her as we love this old girl and think she will be a real beauty when we are finished.

I am open to all your thoughts on this project.....

[ahicks]

From what I see (assuming no rot) I would patiently fix what you have. You would need to pull and replace/re-install everything on the roof using modern sealants that are much sturdier than what's on it now. For bigger projects towards the center of the roof, lay some plywood on the roof to spread your weight out over a couple of rafters. Project very do-able, especially by an individual considering replacing that entire roof. Try not to look at the entire project at once. Do a vent, then another, then something else. Break it down into smaller pieces! I would work from the center out...

I share your enthusiasm for this project! Those old Centuries can charm anyone! We had a 30' TT for a while quite some time ago. Running gear built like a tank!

[Rapid Robert]

I agree with ahicks save the existing roof if you can. Someone has coated it with an elastic roof coating to reflect the heat, as a lot of people do here. It probably was not cleaned properly first so it is peeling. The warping may just be from heating and cooling, aluminum moves around a lot in our climate. If there are no leaks or rot wait a few months until the weather cools a bit and go to work on it as he said. Put your money in the best RV sealants you can get then cover them with Eternabond tape.

[Got Briards]

Century

yeah...i agree; she looks great ... charming lines

IMHO if you re-roof with 4x8' sheets do not just overlap ... regardless what kind of sealer you use ,it will get old one day.
try to seal it mechanically;
if you dont have access to a "J-seam former" i would at least use a sheetmetal brake and bend up a ~1" lip and (almost) flatten it with the clamp-down beam. do the same (but bend downwards) with the next sheet. hook them together and you have a home made interlocking J seam that is virtually waterproof even without sealer

btw
aluminum is difficult to paint due to its surface oxidation ... if the prep work is not done correctly the paint/coat will lift again.
if you decide to re-roof i would suggest to not use bare aluminum; use powdercoated semi trailer siding. PC bonds well to aluminum and is a excellent base for a topcoating to stick to

[leadman]

What you have looks to be repairable. The low areas possibly could be pulled up with suction cups. Then I would make a brace for the interior roof under the area that had sagged. I would use plywood under the ceiling and 2X4s down to the floor. Then inject expanding foam in between the interior ceiling and the roof. This would help keep the roof in the up position. Be aware the foam keeps expanding for awhile so allow for that. I would inject it from the inside so there are no additional holes in the aluminum.
If that works ok then scrape off all the old sealer and reseal per whatever instructions come with the product you buy.

[ahicks]

That roof is laid loose over the stick rafters and fiberglass insulation. There's no luan or anything else to support it evenly (other than areas reinforced for A/C's). It's going to have low and high spots as there's nothing to support it. It's how many/most were built back then. Nothing wrong with it.

[77 Spartan]

I wanted to take a moment to thank each of you for giving me advice about the 5th wheel and we do appreciate your time.

Now the bad news, unfortunately we were unable to get her because my brother in laws' partner threw such a hissy fit and backed out on going to pick her up for us. This clown complained and whined so much that it ended up in a huge dispute and to this day we no longer speak with each other and I will never forget or forgive what they did to us.......

This has hit us , especially me, very hard. We really wanted this classic and had some good dreams of our future owning this baby,not only that, we lost a very good sized deposit......sigh

I am still trying to find out who bought her so we can make an offer as we now have a dually to tow her and the money to buy her back.

If any of you know of a 5th wheel like this one or one similar, could you please send me a private message. I would really appreciate any help from the community regarding finding another 70's Century 5th wheel or where I could search for one. I have tried to search the net, but have come up empty handed.

Hope all is well with y'all, happy trails!

I look forward to your comments and any suggestions about future 5th wheels for sale.

[Senior Chief]

So sorry to hear about losing your rig; its always the pits when family gets to tangling...