Whole Roof Replacement??

bobnelms · 08-25-2022, 05:31 AM

Hi all,

I have a 37 foot Cougar 5th wheel with significant water damage in the left rear section of the roof -- a 12x12 inch portion of the roof in that area is totally rotted. The water leak has been repaired already, but when I took it to an RV repair shop to see what they said about fixing it, they told me THE WHOLE ROOF would have to be replaced.

They said that when they pull back the rubber to expose the rotted area of the roof, there's no way to adequately reseal the rubber to any new plywood involved in a patch repair -- so that the whole rubber roof would have to be replaced.

I can't imagine having to replace the whole rubber roof if all I have is a 12x12 inch section of it IN ONE CORNER that needs to be replaced.

Should I take it to someone else, or are they correct?

wiredgeorge · 08-25-2022, 05:34 AM

They are correct; whole roof needs to be redone and damaged plywood replaced. I have an RVArmor.com roof and will never heave to worry about it. Costly but when you compare to a conventional rubber roof, not crazy expensive. No more maintenance and a lifetime guarantee which is fully transferable to the next owner if the trailer is sold.

bsmith0404 · 08-25-2022, 06:30 AM

It depends if it’s a rubber roof or TPO. A rubber roof has to be replaced. Technically, a TPO roof can be patched, but realistically, that’s for repairing small holes not for replacing entire sections. For a proper repair, the roof needs to be peeled back and the rotted plywood replaced. Even though the section seems to be 12x12, the damage may actually be much larger. You want to make sure it’s all done so you don’t have to deal with it again in a couple years. If it were mine, I’d get the RV armor. They will do the repairs and replace roof with a lifetime warranty as already mentioned. Probably only be about $2k more than a conventional roof. That is one of the few upgrades that I believe actually adds value at resale as well.

**chuckster57** · 08-25-2022, 06:30 AM

When you start peeling back the membrane, it stretches the rubber and often times pulls wood fibers that stick to it. It is extremely difficult to get it to lay down flat and the glue won’t stick very well.

**chuckster57** · 08-25-2022, 07:12 AM

Both EDPM and TPO roofs can be patched. The issue with the OP’s roof is getting the membrane to re adhere to the decking.

bsmith0404 · 08-25-2022, 07:57 AM

Quote:

Originally Posted by chuckster57

Both EDPM and TPO roofs can be patched. The issue with the OP’s roof is getting the membrane to re adhere to the decking.

True, but unless I’m not aware of another method, the TPO can use a heat gun to mold the two parts together making it basically one piece again. EDPM is just sealed using dicor to seal the seam. I don’t consider that a good repair for a large area. Fine for a small tear, but not a roof section repair at least in my opinion. And I agree that the section would need to be replaced vs old roof laid back down. That’s why I say it’s a large repair, can’t just cut off the old part and replace it with new and seal the seam.

roadglide · 08-25-2022, 08:32 AM

Quote:

Originally Posted by bobnelms

Hi all,

I have a 37 foot Cougar 5th wheel with significant water damage in the left rear section of the roof -- a 12x12 inch portion of the roof in that area is totally rotted. The water leak has been repaired already, but when I took it to an RV repair shop to see what they said about fixing it, they told me THE WHOLE ROOF would have to be replaced.

They said that when they pull back the rubber to expose the rotted area of the roof, there's no way to adequately reseal the rubber to any new plywood involved in a patch repair -- so that the whole rubber roof would have to be replaced.

I can't imagine having to replace the whole rubber roof if all I have is a 12x12 inch section of it IN ONE CORNER that needs to be replaced.

Should I take it to someone else, or are they correct?

. I repaired the front cap area with 1/6 inch aluminum . It formed beautiful over and around the ac area it’s been on the roof for over 5 years and painted it with EPDM rubbed roof coating. I used lots of dicor and screws every 4 inches . I cut aluminum with a small grinder and metal blade its probably not safe thats why I use welding glove and welding hood.

wiredgeorge · 08-25-2022, 09:05 AM

Quote:

Originally Posted by roadglide

. I repaired the front cap area with 1/6 inch aluminum . It formed beautiful over and around the ac area it’s been on the roof for over 5 years and painted it with EPDM rubbed roof coating. I used lots of dicor and screws every 4 inches . I cut aluminum with a small grinder and metal blade its probably not safe thats why I use welding glove and welding hood.

You need to post a picture Jerry. Not sure why the manufacturers don't do it like that. Seems it would be less expensive and less prone to damage and leaks but you would still need to seal around penetrations.

Javi · 08-25-2022, 12:27 PM

If I need a roof replacement

https://youtu.be/7atCc_LfrHY

wiredgeorge · 08-25-2022, 03:42 PM

Quote:

Originally Posted by Javi

If I need a roof replacement

https://youtu.be/7atCc_LfrHY

When RV Armor reinstalled my air conditioner they put some of that tape like stuff (I didn't see it done so not sure what the material is but it is the same as around all other penetrations) and put it over the edges of the A/C opening and coated it as well. The workmanship was top notch on our install.

**sourdough** · 08-25-2022, 04:58 PM

I'm a little nit picky but don't those "seams" that run the length of the trailer kind of put you off? Sort of like 40' runs of Eternabond? I guess if it functions OK without problems that might offset it.

Javi · 08-25-2022, 05:22 PM

Quote:

Originally Posted by sourdough

I'm a little nit picky but don't those "seams" that run the length of the trailer kind of put you off? Sort of like 40' runs of Eternabond? I guess if it functions OK without problems that might offset it.

They don't bother me at all.

bobnelms · 08-26-2022, 06:24 AM

Thanks for all your input. But I'm still inclined to go with a patch job instead of having the whole roof replaced. I'm 75, and intend to keep the rig for another 5 years or so -- and I think a patch job might be sufficient as opposed to a multi-thousand dollar repair. Here's my follow-up questions:

1. What material are the roof trusses -- aluminum?
2. If aluminum, how is the plywood roof attached to it?
3. Why can't I simply replace one section of the plywood, and then cover and adere it with new TPO and then tape the interface with wide, reinforced strips of eternabond?

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