I found the leak in my roof.It is aluminum and there is what looks like rust holes. I taped over them with duct tape for now. It seems to be just the front right quadrant affected, the rest of the roof is solid.Preventative maintenance needs to be done.How should I fix the holes?I was thinking of just putting new aluminum sheets over the front 8 feet of roof. Maybe some sort of glue between roof and new metal.??What is best for the rest of the roof that has not yet decayed? Just rubber membrane coating??

Bondo all purpose. Cheap, easy to work with and dries hard. Use slightly less hardener than called for and you have a little more working time. It will take a EPDM paint if you decide to coat the patch or the whole roof and if not will keep water out by it self.

O'd be first concerned with what the leak did under the skin and then address the leak.

Bondo a good idea.The roof is thin metal, will the Bondo crack if roof moves?Sidecarflip, The water got the ceiling wet, the vinyl wall paper on ceiling kept it water tight, it stayed wet, not really rotted though. I pulled it all out of areas over the metal framing, pulled plys off, and left the las ply that is bonded to the foam. Hoping it will dry and make things easier to glue back up as easier to glue to wood than this white foam.One wall is wet, and everything except the exterior skin removed. Keeping the skin intact and fixing from the inside so I do not have to pull the entire outer skin off the 22 foot length… Hoping it works , no reason not to…

Wood does rot when wet (and enclosed and light tight). What happens to RV's they rot. The reason why your aluminum roof perforated in the first place was water under it and the water coupled with the mold, attacked the aluminum from the underside causing corrosion and your hole issues. It corroded from underneath not from the outside.After you mitigate the intrusion issue and only after, I'd repair the perforations with sheet aluminum sealed to the original roof with either Dicor or Sikaflex. Don't think Bondo is the correct solution to the repair.

I am considering applying a rubberized coating over the entire roof. Like Elastomeric Metal RV Roof Coating.Patching the holes with something first…I guess I need to rip out the styrofoam also since it is saturated, or will it dry now that the ceiling is out?Wood underwater does not rot, it needs air. Mine stayed wet all the time and I was intrigued that it had not rotted. but That is a non-issue here though. Has no bearing or significance. tks

Holie roof | Good Sam Community

time2roll
Nomad
Dec 06, 2017
I would have it ripped off and rebuilt of different material.

http://rvroof.com/

Good luck.
72cougarxr7
Explorer
Dec 06, 2017
I have seen aluminum corrosion like that caused by contact with steel staples, any moisture will corrode the dis similar metals.
I had a spot in mine do that, on a wall, I sanded, and filled the hole with JB weld epoxy.
ScottG
Nomad
Dec 05, 2017
Sometimes there are contaminates in aluminum that will cause a spot to corrode almost like metal rusts, except the corrosion is white-ish.
DownTheAvenue
Explorer
Dec 05, 2017
There is a product called Kool Seal that is designed for mobile home metal roofs which would work quite well in this situation. Use the fabric membrane over the holes, and put the Kool Seal over the entire roof. It should make a completely water proof roof, seal the holes, and tolerate anymore corrosion. I would not tear out any of the interior ceiling, just Kool Seal the exterior.
ajriding
Explorer II
Dec 04, 2017
Yea, DTA, I think it was galvanic corrosion. Maybe humidity caught inside ceiling acted to aid the process.

Now I do not think there is an easy fix. Im looking at tearing out the ceiling all the way up to just the metal roof (ceiling panel, foam, 1/8 plywood), but just the front half. I think the rear is fine, for now at least, and if not I will deal with it years down the road.
DownTheAvenue
Explorer
Dec 04, 2017
SidecarFlip wrote:
Wood does rot when wet (and enclosed and light tight). What happens to RV's they rot. The reason why your aluminum roof perforated in the first place was water under it and the water coupled with the mold, attacked the aluminum from the underside causing corrosion and your hole issues. It corroded from underneath not from the outside.

According to this statement, water and mold caused the aluminium to corrode. I DON"T THINK SO! Water will not cause aluminium to corrode! Mold will not cause aluminium to corrode! I bet there were dissimilar metals touching which will cause aluminium to corrode, especially when exposed to a damp environment.

I bet the aluminium roof was touching metal staples in the roof truss and dampness caused electrolysis.
NMDriver
Explorer
Dec 04, 2017
If you are just filling the holes and then putting a stretchable EPDM paint on over it I do not think the Bondo will come loose especially if you push it into the holes.

If you were going to try the bondo on the whole area and the roof flexed then it may pop loose over time. I am not sure about a large area coverage and a flexible metal roof. Ask some auto body shop about the Bondo for body repair. The Bondo for metal may be just enough different from the All Purpose Bondo that it adheres better.

I use the All Purpose on seams and to fix wood damage. My roof is wood covered in EPDM with metal around the edge and vents, etc.. I have used the Bondo with good results on the metal and to bond wood to wood and wood to metal. The bondo on my repairs has been good for a long time. One painted wood/bondo support has held up to years of exposure in my back yard.
ajriding
Explorer II
Dec 04, 2017
Herculiner being spray-on truck bed liner?

I am wondering if this started from a tree branch laying on the roof pooling water. The person I bought it from no, but maybe the other owner, 6 months removed, had it parked under low branches. Damage seems to be concentrated in one area with 26 spots I found, and only 4 to the left, and none on the other side.

Wondering so I am sure to find the source, but if I rubber coat it then that will get all the leaks…
wa8yxm
Explorer III
Dec 04, 2017
Well you have two choices. Ihe metal around those holes is solid.. SNOW COAT or one of the other liquid roof products

If the metal is getting kind of like a dry leaf (Easily Crumnbled) New Metal Roof,
pianotuna
Nomad III
Dec 04, 2017
At least one member has used Herculiner to repair a roof.