Roof, Roof, (and we're not talking dogs here)

[Larry Dedrick]

Ed:
       I just took a crash refresher course on galvanic corrosion, and the state of the steel screws that were removed, from an aluminum frame, appear to be the sacrificial metal. The illustration that was used to demonstrate galvanic corrosion was a steel rivet into aluminum. However, the ceramic coating, on the screws you suggested, will definitely serve as an insulator and thus help prevent corrosion. Bottom line we both can agree on, the screws were definitely corroded and in my case, severely corroded.

Adam:
       Although the Tech that repaired my roof separation did not lay a bead of of silicone, I certainly would have. Also, a shot of silicone in the hole as well, so the shank and head of the fastener are sealed. Good luck with your project.

                                              Larry D.  

[Edward Buker]

Adam,

If I remember doing this repair, it was awhile ago, I think the area behind the wall structure was not a readily accessible area to put sealant on. I think the gutter trim was still attached to the roof structure and you end up pulling the roof in with the attached gutter strip that overlaps and then in turn pulls in the wall also if that has pulled out. The top of the wall is behind the gutter strip and there is little space there that would allow access. You are basically bowing the roof section back tight to the underlying metal sidewall and catching the wall structure in the process. If the wall could be better adhered I would probably use an adhesive rather than silicone. I do not think this is necessary if the gutter strip is well fastened and ties the top of the wall.

If you have this problem, you are living with an access point where water can get behind the wall, as well as wall panels that flex more while driving and may in time delaminate the adhesives that are holding the wall panels to the frame to a greater extent. Beaver had adhesion problems with this frame to wall panel joint and keeping things mechanically fastened at the edges can only help.

Later Ed

[Adam Hicklin]

Ed, on mine the roof cap and the gutter separated together so there is about a half inch gap between the side panel and the cap/gutter.  Certainly enough room to squeeze some goo in there.  I like the idea of an adhesive.  I'll try to send a picture tomorrow.  

[Wayne Tull]

Timely thread as I was planning repairs to address water leaks in this area of the coach, of course in this part of the country 70 degree weather is ways out in the future.

[Edward Buker]

The screw dimensions that I used would probably be fine for most Marquis. As Joel pointed out there are some construction differences and I think the Patriot walls may be a bit thinner and therefor you may need a shorter screw if you own a Patriot. Not sure what you used Joel and if your screws terminated length wise in a rectangular aluminum tube. A test hole drilled through the gutter on a non delaminated tight section of wall would be good. Drill until you hit metal behind the wall structure and then add maybe a half inch of length and that should work.

Later Ed

[Keith Oliver]

Regular Reader will recall that I have posted on this subject in the past.  Here is my latest instalment.

On the passenger side, I have been chasing leaks for about a year.  In redoing the valences I discovered and repaired extensive rot in the passenger sidewall between the two large windows.  I sourced the leak to the  total  lack of water protection on the window installation, resulting in water migrating upward as well as downward from the window openings, getting into the thin plywood and travelling where that would lead.  After fully repairing the window openings, I still have a tiny water leak, so todays report is of taking the gutter off and fixing it.

Like the window installation, the gutter was installed originally with no attention being paid to making the joint between the roof/front and rear caps/sidewall water tight before adding the gutter.  I found the roof rivetted to the sidewalls every 24 to 30 inches, but no caulking whatsoever along that joint, the cap not attached in any way to the sidewall, and a gap of up to 3/8 inch between the cap and sidewall, behind which the rotting plywood is plainly visible, no caulking in evidence.  Over the whole, the gutter is screwed, about every 8 inches.  Between the gutter and the bottom edge of the cap is a tape of mastic, very sticky stuff, but in a location that stands proud of the cap by about 1/16th in, so touching rarely, protecting nothing.  More disappointing, nothing to prevent the water being driven up from under the gutter, along the sidewall, entering the space between the sidewall and the roof, which will happen if ever you drive in the rain.  (what were they thinking?  We live in a rainforest, so have to expect to drive in the rain from time to time)  Some misguided PO had tried to correct some of these deficiencies with copious quantities of silicone, but regular reader will recall my rants against any use of that product in an outdoor environment.  Naturally, all the silicone was doing at present was to hold in some of the water that it had allowed to penetrate.
All of the screw heads (rough count, 50 on a side) were rusted.  About half of the screw shafts also rusted, so this indicates water perpetually using the screw as a pathway to the inside.  
I bought a new plastic strip (Camping World, 100 ft for ~ $30), Replaced all of the screws, caulked the joint with Lexel, dabbed every screwhole and later, every screw head with Lexel and ran a bead of Lexel above and below the gutter extrusion after fastening.  All that remains is to clean off the slops and shine up the fibregalass.  The job took about 4 hours total, a borrowed ladder, 2 tubes of Lexel, 50 screws, 1/2 a pack of plastic strip.  When I get to the other side, it should go alittle faster.

[Carl Marchant]

I have 98 beaver with pin holes in the fiberglass roof. My question is those who have put deck paint on roof will this paint seal those holes or do I need to take another route??? My other route was to use rvroof in Green Cove Springs Florida. They offer 20 year guarantee and I know this would stop all present leaks as well as future ones.
Thanks in advance for your advise

[Gerald Farris]

Carl,
If you have pin holes in the fiberglass roof, you need to use something thicker deck paint to coat your roof with. A rubberized bed liner type coating is normally the preferred solution for your problem.

Gerald  

[Andy Clark]

Larry,

The screws I used were ceramic coated hardened steel screws. They are designed for building aluminum structures. I have never seen one corrode and I live in a salt environment here. I do not think that dissimilar metals or galvanic reaction played much of a role here with the original fastener failure. They were just a poorly protected steel screw and the gutter strip behind the rubber is a recess that fills with water and seeps around a poorly sealed screw. On the inside of the wall there is probably a lot of condensation available with the frame metal surfaces against the outside wall as cooling occurs. I know there was literally nothing left of the screws that let loose on my trim strip but it just looked like rust and not a galvanic reaction to me. You are right that dissimilar metals are not optimal but the ceramic coating is very tough, a good isolator, and is very corrosion resistant. Rivets are fast to work with but I do not love them for this application either. I like your idea of screwing the side wall and gutter strip somewhere down the road when you have time and the parts. Glad you are back having fun.

Later Ed

I posted info about my fix to this problem several months ago. The reason for this post is to address an additional associated installation error made by the factory. Ed alluded to it in the above quote.

It's this....the void behind the gutter trim does indeed fill with water and any weakness in the sealing of the screw heads will allow water intrusuiion into the wall. The fix for this is...at the extreme forward and aft ends of the gutter strip cover, the factory actually sealed tight the open ends of the flexible trim. You need to open up both front and rear of the strip so that air can flow through and keep it dry behind the cover (strip). It's kinda like the open ended rockers in old cars that were designed for flow-through ventilation for exactly the same reason-namely the prevention of water build-up.
Andy