Class C Bunk water damage repair & roof seam seal

I purchased a 92 Fleetwood Jamboree last summer.  I had noticed after purchasing it that some of the screws in the seam under the front cap of the cab over portion were rusted and falling out.

I just got back from a 2 week trip and decided to investigate what was going on.  I pulled the mattresses out of the bunk and started poking around.  I was able to put my hand through a lot of the plywood within a foot of the front of the cab over.  Wood farther back seems sound.

So, I tore into it and pulled the curtains, trim, etc to really see what was going on.  The plywood is pretty much rotted out for the whole front section of the bunk bed and I figure I'll just replace the whole section.  The ceiling and side walls seems sound.  I pulled some of the fabric off the ceiling and all of the wood seems dry and sound.

Other then the lower seem, I can't seem to find any other places where there is evidence of water entry.  I'm finding it hard to believe that enough moisture entered through the lower seam to rot out both the plywood and panelling on the bunk, which isn't even in contact with the fiberglass.

The windows seems to be sealed up well.  No obvious water marks.  I went up on the roof, and the caulking on the top seems looks like it could use replacing;  some cracks and gaps.  I also noticed that the rubber roof is not intact with the roof panels between the cab over vent and the front seem.  This seems to indicate some water intrusion, but again, no evidence of that from the inside.  I want to be sure to fix the leak that caused the damage in the first place.

So, here are my questions:
1)  It looks like I can just unbolt the plywood bunk and replace it.  It seems to be attached to the front and sides using angle iron (iron in the front...galvanized steel on the sides).  Is this a structural piece?  This doen'st look difficult, but maybe I am missing something?

2)  Does the bubble in the roof rubber mean I need to replace the entire roof, or can I just glue it down.  I'm thinking that since it is near the front cap seam, I can just re-glue it and then re-do the seam.

3)  The bottom seam has a little trim piece that covers it.  It currently has a bunch of silicone all around (most likely a previous attempt to fix a leak?).  I was thinking of using Eternabond on the inside and caulk on the outside (since it will show). Will Eternabond work when applied from the inside?

I am also considering putting some kind of backer board for the screws to screw into.  Currently, they either went into the plywood bunk or just into the fiberglass.  I'm also considering adding a piece of trim between the leading edge of the cap and the seam to break up the water flow into the seam.  I noticed while driving in the rain that water runs back along the underside of the cab over right into the seam.  No question here, but input is appreciated.

I plan to remove the windows and reseal them.  I also plan to redo all the roof seams with Eternabond.    My preference is to remove the old sealer first and have a cleaner repair.  I've read plenty of thread on Eternabond vs. Caulk/Dicor, and think Eternabond is the solution for me.

Any and all input is appreciated.

The linked pics show the damage I caused by "poking around" in the bunk, the lower seam and the upper seam.  The area between the upper seam and the vent in the picture is where the roofing material is "bubbled" (hard to see in the pic).


Thanks.

The cab-over section of a Class C is notorious for leaks such as you have found. It sounds like you are doing a thorough job if repairing it, though.

1)  It looks like I can just unbolt the plywood bunk and replace it.  It seems to be attached to the front and sides using angle iron (iron in the front...galvanized steel on the sides).  Is this a structural piece?  This doen'st look difficult, but maybe I am missing something?

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I doubt if it is structural, but do not know that for a fact. I would guess the metal is just to support the bunk, but it may contribute to the stiffness of the cab-over area.

2)  Does the bubble in the roof rubber mean I need to replace the entire roof, or can I just glue it down.

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Just glue it down.

Will Eternabond work when applied from the inside?

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Yes, fairly well, but be sure to caulk the outside as well. If water pooled on top of the Eternabond, it could gradually seep through the bond as the continuous weight of the water pushes the adhesive away.

Backer boards would be a good addition, I think.

I got the cab over area gutted down to the fiberglass, except for the walls, which I don't think I can disassembly without actually taking the walls off.

All the wood in the bunk showed sings of being wet.  Everything from stains to the posted rotted out section.

I put a sprinkler on the roof and sat inside until I started seeing leaks.  The leaks showed up at the front corners of the cab over section.

I figure the leaks are starting on either the top seam, or maybe on the side seam that follows the edge of the cab over.

CW is offering a free leak check if you purchase over $100 of stuff.  I recently got a battery there, so they will do the leak test for me next weekend.  I'll be posting agin then and updating the pictures on my Google page.

I put a sprinkler on the roof and sat inside until I started seeing leaks.  The leaks showed up at the front corners of the cab over section.

I figure the leaks are starting on either the top seam, or maybe on the side seam that follows the edge of the cab over.

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That would be very typical of Class C construction. Most of them leak there after awhile.

Update...

Well, the leak test found leaks were I suspected, in the front corners of the front cap, and a few around some windows, etc that will be easy to fix.

Fortunately, no leaks on the roof!

Here's a tip for you....don't try driving your class C with the trim pulled off the underside of the cab over part.  The pressure of the wind off the windshield tore open the seam.  It must have been a hilarious sight as all the wood pieces and dust from the rotted plywood went flying around the inside of the RV.  Fortunatley, I was able to pull over and deal with the problem.  I should have gone back home, but instead used lots of duct tape, and put enough weight in the bunk area to keep it from opening up much.  Still, I had to drive about 45MPH the entire way (about 5 miles) on the freeway.  I used more weight on the way home and things were fine (still staying under 50MPH).

As mentioned above, I had pulled off all the front trim to investigate things.  After returning from CW, I pulled of the old sealant and cleaned things up.  I got some new sealant and Eternabond from Best Materials and have repaired the front seam.  I used Eternabond on the inside and new sealant on  the outside.  I filled in some of the larger gaps before applying a continuous strip along the whole seam.  I used some luan board as backing.

The paint was peeling off the trim, so I stripped and repainted it.  Some I found some Duplicolor at NAPA that was a close match.  it came out pretty good and I used it on the screws as well (they were already coated for corrosion).


I plan to soak the luan board in CPES, which is a competing product to Git-Rot (www.rotdoctor.com) and will be using the same for the board along the front of the bunk area which is showing some water damage.  I'll also back up this board by gluing and screwing a piece of 1/2" plywood to it.

So far, so good.  These projects gone go one of 2 ways once you decide to tear into things.  Either the spin out of control and you wish you never started (how many projects have I had to abandon?) or things go pretty much as planned.  This one is the later, fortunately.

At this point, I can drive Madge again, which is great as I'd like to go to the coast next weekend.  I just don't have a bunk, but that's OK.

I'm waiting for the CPES, so the next step is to weld up a new bracket for the bunk.  I plan to do that this weekend, though I won't install it until all the side seams have been repaired and I've tested for leaks again.

I should have updated photos soon.  See the link in the OP.

Very impressive and complete repair (so far) ... the photos really do a great job of showing the progression!  I've got to say congrats for doing this repair yourself.  It sounds like you never really had any reservations about it, but it is quite an undertaking that many folks may not even attempt.  I'm no good at fabricating replacement parts/panels out of wood and other materials.  You saved yourself hundreds if not thousands of dollars by doing the job yourself no doubt.  Did CW ever give you any kind of estimate?

I never asked.  I figured as long as I was careful in disassembly, I wouldn't make things worse.
It is a lot of work, though none of it seem to require great skills. 

I think the hardest part is not having a guide of any sort.  Not understanding how the rv was put together makes it difficult.

I think there is a place in the market for an RV restoration book.  I have a book for restoring old motorcycles.  It is not brand/model specific, but just goes into the methods used at the time.

Part of the enjoyment is figuring things out.  It's also part of the stress and is delaying things as I ponder what to do.

As for doing it myself...I didn't have the budget for anything else.  I also have a number of friends with experience in building hot rods and restoring old cars, including one whose a pretty good welder and owns a plasma cutter.  If I get in over my head, I have some support.  I also have this forum which has been a great help.

Thanks for the kudos.  It's fun to share your work in pictures.  It's interesting how the net has changed how we work.  We know think a lot more about taking pictures and describing what we are doing to help out others.

James

I'm back...

Project was put on hold due to other projects that were deemed more important (only bathroom in the house needed finishing) and being short handed at work.

So, when we last left off, everything had been gutted and I'm ready to start re-assembly.  I made a new bracket for the front of the plywood bed support, but in my haste, heath from welding warped it.  I cut it into 3 sections and think I can still use it if I route down the plywood a bit so it fill fit; the new brackets have a channel to support the plywood from the bottom and allow me to screw into it from the top..sort of looks like this:
  \
  \___
    \____

Over the winter, I notied quite a bit of water collecting in the cab over, I don't think I made the existing leaks any worse, but my repear on the bottom seam doesn't give the water any where to go.  I sucked it all out and put a tarp over the front to keep it dry over the winter. 

I recaulked the leaking seam pretty well, but think it may need a bit of sealer over the caulk.  I read about this somewhere on the forum.  I need to re-acquaint my self with what to do here.  I know the leak is on the side  (front corner of the cab-over) and not the top because I had it tested at CW.

We've still been using the RV, during the project.  We just lost use of the cab-over area.

Glad to be back!

magconpres-
Welcome back.  Once you figure all of this out for your class C, let me know if you get bored and I will "let" you work on mine!

Camera's out of commission, so no pics, but she's almost done.
Welding up the brackets took some time.  It wasn't as much the welding, as it was the grinding. 
A got 2 lessons out of that:
1)  take your time welding.  I put too much heat into the steel and warped it.  I had to mount the brackets in a vice with some spacers to bend the past "flat" so they would get unsprung.  That added some time, but no real effort, to the whole thing.
2)  Don't take you eye protection off until you're done cleaning up.  I did and when sweeping up a particle of metal dust landed in my eye.  I didn't notice it for about 3 days (until it started to rust)  I noticed the night before a business trip.  Since I didnt' want to live with it for 3 more days, I had to visit the ER.  That added $800 to my project and pretty much blew my budget.  Other than that, I think I have about $2oo into the repair.

back in the cab, I put the CPES on the board that runs only the front of the cab-over.  This is the board that the bracket bolted to.  It was pretty rotted out for the bottom 2 inches, but the top 3 were solid.  After letting the CPES cure, I glued and screwed some 3/4" plywood to it to provide some good wood for the bracket to screw to.  I screwed this using the top 3 inches (into the good wood on the original board), and then screwed my new brackets to the bottom section.

With the bracket in place, it was just a matter of cutting some 3/4 inch plywood to fit.  The original setup had the seam running across the width of the rv.  I had to cut the original wood lengthwise (front to back) to get it out, and did the same thing for putting in t the new wood.  With the new brackets, I didn't even need screws in the front (the new brackets support the wood from the bottom).  I didn't like how the seam was flexing, so I routed out space for some 1/8" mending plates and screwed two of the across the seam.

Things got much easier from then on as I now had a platform that could support my weight.  I put in the side brackets (the oringals were in good shape). and screwed up into the new platform through the sheet metal sa it was originally.  Everything is now very solid.

I have put all the trim back in the cab, so it looks good again.

I have a few things left to do:
1)  screw up through the trim piece on the bottom of the cab-over into the new platform (this was the original symptom and is in the pictures I posted)  Those screws stick up about 1/2 in into the bed sction and had to be removed to put in the plywood.
2)  put a 1/8" piece of plywood on top of the 3/4 to finish it out.  I was going to use some counter-top laminate, but it was too expensive and too thin.
3)  Build some storage cubbies up top.  The original design had some boxed sections covering the brackets that run down the sides of the bed.  They are about 5" tall and 5" deep.  I figure I can make some pockets in them for keeping a cell-phone, watch, wallet, etc.  It's essentially wasted space, and it would be nice to do something "extra" for all the work I've put into this.

I'd say that if I could have worked on this straight through I could have wrapped it up in a week.  It really didn't take that long, but I had a lot of interruptions and needed lots of time to think things through.

Would I do it again?  Absolutely!  Would I recommend that someone else in the same situation try it?  That depends on the person, but in general yes.  Anyone with some basic home repair skills could have tackled this.  I think the hardest part was just wrestling with awkward shapes of plywood.  I didn't have to rebuild the bracket.  I could have treated the old one for rust, painted it, and re-used it.  It would probably have lasted another 10 years if kept dry.  Or I could have paid someone to weld it for me (in my case, I probably would have come out ahead given the $800 ER bill).

My next project now that my confidence is up is to re-do the interior.  I plan to update the colors and put in some cork flooring.  That'll wait until the winter to start.  In the meantime, I do plan to upgrade to a smart charger.

Enjoy the summer everyone!

Is there any chance you're still around? Love to chat with someone who's been there/done that!

My status is the bunk area had rotten flooring (bed frame). I've removed all the old rotten frame, and most of the plywood interior skin. I fixed a temporary frame that kept weight off the skin (attached to solid frame coming down off the ceiling and fixed to solid areas house side of the bunk) but now looking at a more permanent repair.

If like to fully remove the soft frame that the seam at the front of the cab is attached to.

Ideally I'd like to replace that bunk floor section entirely, but not sure how to go about it. Would I remove the side/wall seam/trims and front trim and literally slide a new sheet and screw it onto a new frame? Is the old seam trim reusable or is new trim required (and does that mean enough to retrim the whole roof?).

I would like to make sure I'm neither over complicating (redo entire seam/clamps/3 people/ 2 months/new everything,) or over simplifying (reuse existing trim/just slide in new sheet).

Any thoughts?

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Thanks, I might give it a try.