More lessons; am I learning?

[Wade]

My 85 Coachmen has a metal roof. I thought it was in pretty good shape as the water damage appears rather minor from my experience with old RVs.  The worst of it appeared to be, surprise surprise, over the cab. It looked like most of the leaking had been addressed and I believe most of it has been.  At some point I plan on removing the emergency exit and replacing it and addressing the damage over the cab. However, there was only one small leak at the emergency exit and I fixed that the first week I had the camper and it continues to hold.

Looks can be deceiving and I believe that my roof is much more deteriorated than I originally thought. Although, after spending a fair amount of time on it, I do not believe the damage is bad as the deterioration should suggest. I think the POs did enough maintenance to limit the damage but I still have the deterioration to deal with.  I truly know nothing and hopefully sharing my experience will either enlighten me or save someone else. I doubt very much that what I am going through is not something that others on the list have went through already.  Here is what has happened:

If I were truly a wise shopper, obviously the sundraders are desirable for good reason;-)  With a metal roof I had a huge red flag that unfortunately I saw as a welcome mat.  The interior damage was minor, rain just before we looked at it and nothing was wet so I thought it was all good. The back was nice shiny white metal and the seams had reinforcing tape coated with rubber and that rubber coating covered the roof in front of that shiny white metal that covered about the rear third.

This is what I am pretty sure I have: I have a metal roof that is developing pin holes from corrosion. I know that the past three years the unit had been stored inside. I also know that at some point, the unit had a new rooftop air installed. (That is the one thing I don't have the paperwork for but I do have it for the original unit and this is not that.) Pretty sure that when they installed the new rooftop unit they put a new piece of metal on the roof and decided that a bit of elastomeric sealant over the rest would be good enough.  Perhaps with vigilant maintenance it will be?

As I said in another post, I developed a leak on our first big trip. It came out at the center vent but the center vent was tightly sealed. I saw bubbles in the eleastomeric sealant and thought it was just bubbled due to bad application and that when the bubbles broke the leak started.  Likely true except for the application as the cause. I now believe that the "bubbles" in the elastomeric sealant are more likely being caused by the corrosion process.  In any case, I have no shop or roof to work under and the eleastomeric sealant can't be applied when temps are going to go below 60 or rain within 24 hours.  Had to do something quick due to my living situation. I scrubbed and rinsed really thoroughly and then covered everything ahead of the new metal with elastomeric roof patch. The aggressive scrubbing has convinced me that I have corrosion under the roof patch.  After it cured I could even see some bleed through and a bit of texture even in places that were not "bubbled" before hand.  The first coat stopped the leak but showed the bleed through and covered more places that the scrubbing exposed. 

Had one more weather window so I went for a second coat. This time I thought it prudent to make a "rubber mache" so to speak.  Used polyester roof patch over all the areas where I could see that there was corrosion underneath. Laid the cloth down over wet roof patch and then covered it completely with more roof patch.  I am currently dry and hoping that it will hold up for a couple of years at least. Not sure what the next "correct" step will be.  Hoping to gain some more insight from posting this.

Thanks!

Wade

 

 

[Back East Don]

I am of the opinion that aluminum roof rot will become far more common place.  The roof is a thin painted skin and that paint is by now old and faded.  Add to this the lack of care the roof gets, as in, out of sight, out of mind.  Most attempt to deal with it only after water has already done a great deal of damage.  Get moisture trapped in the skin of an RV, I think it will do far more damage from underneath than from the outer surface to the metal.

I had tons of rot and resultant pin holes.  Some were pretty large especially under where the AC was.  The previous owner did what you are doing.  Mine had house roofing products all around the vents and seams.  Not knowing any better, I attempted to repair all the cracked seams from the previous work done and while it took care of most of the infiltration, I still had lingering water getting into the corners of the berth.  At first I thought it must be the windows.  I took them out and resealed them and yup, still had water coming in.  Spent a few years working at it and thinking I had it only to once again have albeit small bits of water getting in.  

I do hope this works out for you but will also say, I did not like the performance of home roof products and don't think they are suitable for an RV.  There is a decent amount of flex and movement the RV has.  Products that dry and don't remain pliable are more likely to fail as a result.  Just my opinion.  Perhaps others will have a counter experience.

[hunkaman]

hey there wade:   your roof issues are sounding really close to mine.  i have a 93 warrior winne with the thin alum roof.  my story?  background, bought almost one year ago. only made one short (150 miles round trip ) voyage last sept. was raining from time of departure to return. at times heavy rain, mostly steady drizzle, noticed absolutely no leakage until may 2016. after a severe hail storm. my winnie was stored from nov 1 to april 1 in indoor storage. only noticed leakage when felt dampness on the couch/bed behind drivers seat.  when i got the ladder out, saw that the hail broke the front roof vent cover. but also noticed dozens of bubbled up areas on roof surface. scraped away the bubble areas and realized the aluminum under the thin coating had degraded resulting in trapping moisture throughout the entire roof area, rotting the plywood below the aluminum sheet. currently it is in the local rv shop getting entire new roof with new interior ceiling panels as well. has been in shop all summer may get it back next spring, insurance paid the cost, approx. 6k  what is troubling to me is this damage was already there and undetectable to me. the hail storm broke the vent cover , but the rv guy said the damage from the bubbles on the roof had been going on for some time prior to my buying the unit.  after that first, and sadly only trip, last sept in the pouring rain the whole time, i would have thought any roof leaking should have been evident. but it was not. no visible water stains, standing water, or other signs. i spent many hours in and out of the rig before i indoor stored it on nov. 1 and noticed nothing that would have alerted me to the roof issue. i am also a newbie to motorhome rving. and this site is wonderful. so many helpful and knowledgeable owners willing to share their information and experiences.  what i learned is a couple things: one, if your roof does not leak KEEP IT THAT WAY, and two, rv roofs require rv materials, they have special needs due to flexing, expansion, contraction, uv damage ,etc. hope you get yours all fixed and water tight, good luck joe from dover

[Wade]

Thank you for your replies! I am just hoping to get one more season out of it with my current repairs holding.  Two would be even better. However, it sounds like that may be living in a dream world?

At least I am pretty sure I know what is going on now. Not looking forward to fixing it but OTOH, should not be the worst thing I've done lately either.  Oh do I miss the days of having a pole shed though;-)  I do love the city but city living does make some things much more difficult.

Wade

[Back East Don]

I took what some think is the extreme option which is to cover the entire roof in liquid EPDM rubber.  The only thing that complicated doing that job was the petroleum solvent based roof products that were done previously.  If I had a roof that was just the painted aluminum, I could have completed mine in a few days.  One day to clean then remove all the old lap sealant. do any minor repairs and replace any vents as needed.  Second day would be tape the edges then prime.  Last day is coat with EPDM.  The last two days would only be a partial days work.  I compounded the problem by not dealing with it correctly and adding more of what didn't work.

You'll likely get a couple season out of it especially if you've gone heavy around the seams.  The issue I see is that these little Toyota's flex and shift quite a bit and the roof sealants often dries too hard to flex with it.  I've received a number of private inquiries regarding the EPDM.    Cost is often used as a reason for going with household products even after protracted dialogs about longevity.  6 tubes of lap sealant, replacement plumbing & refrigerator vents plus base and two gallons of EPDM and a quart of primer should run you just over $300.  Anyone who has an untouched roof that reads this and thinks it is too much money or bother is only hurting themselves in the long run.  Would not hesitate for a second to use this on the next RV I get if compatible.

The problem is that like many of us, we buy these with what ever baggage the previous owner left us with.  I had probably as extreme a case as you will find and simply made a bad situation worse.  Removing the old roof sealant was a pain but the primer is intended to seal the asphalt based products so in theory I could just prime and cover over any of it.   I sealed mine up and I've been bone dry for two season now.  I wash the top a few times during the season and inspect the top to see how everything is holding up.  The road grime washes right off and it looks great.

[markwilliam1]

I have a 1985 Granville that has the original Untouched metal roof! The metal has never even been painted. All original butyl tape under the metal strip (holding the roof down)  and a thin bead of caulking on the edges. I am blessed with absolutely no leaks anywhere on the roof. Don't understand why. After reading Don's post about pin holes, etc. I know I better act. Thanks Don!! Scrubbed the roof with simple green  then wiped hard with acetone. Removed all caulking, took off the deteriorated strip that covers all the screws and replaceed all screws with Stainless Steel screws coated with Flex Seal. After sealing the screws I used 6 tubes of Dicor Lap sealant around EVERYTHING. I am using a product called Snow Roof. It has a 12 year warranty. Very easy to use as it goes on blue and dries very white. Around $150 for 5 gallons. So far I have 2 coats to go. Noticed my roof is far from flat. Many depressions that hold a little water. Don't like walking on it as it flexes a lot. After final painting I will go over all areas covered with lap sealant using eternabond tape. Hopefully I won't have to worry for awhile. Still can't believe this original not touched in 31 years roof doesn't leak!! Good Luck Everyone!

[Totem]

I had an all aluminum dutch kettle pot for fish and turkey frying that served me well over the years that eventually stopped working so well.

we loved boiling sweetcorn in it.

It had the typical moon unit propane grill tank powered burner that it sat on and stayeed at my deer/fish camp. As the years aged it it stopped holding a flame or rather it would flame great and then fizzle out. We simply couldn't understand it. Then one day i fired up just the moon unit without the fryer and let her burn.. she didnt go out.

I placed the kettle on and waited and she went out. I then noticed the steam drips... the kettle had pin holes in the aluminum. tiny ones so small they wouldn't even drip.. but visible if you held the kettle up to the sky. the kettle would heat up and spray steam water onto the burner and extinguish it. Fortunately for me i didnt catch any pan fish up there or turkey that year...Im sure that thing would have gone full meltdown had it had oil in it.

Edited August 29, 2016 by Totem