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While doing some routine maintenance, I was alarmed to find some moisture under the cabover bed today. Our 91 Warrior stays under a cover 24-7 to help prevent this kind of water damage: http://www.amazon.com/dp/B007TKJLRW/ref=pe_385040_121528360_TE_dp_1

My alarm turned to complete dismay when I discovered layer after layer of mushy, rotten wood over the cab. I'm going to need your tips/tricks to figure all this out, for sure. To start, here are a few questions:

1) Do covers really offer much protection from rain?

2) Just about everything under the bed is ruined, but the sidewalls seem firm/solid; will I need to tear those vertical sidewalls apart in order to rebuild the "base" area?

3) Does anyone have a drawing that might correspond to the structure of my Winne?

4) In the second photo I'm attaching, you can see the piece that joins the two outer sections of fiberglass skin. There was no trace of adhesive/caulk/butyl where those pieces come together... I know this seam is on the underside, but surely there's still a need for some waterproofing. (?)

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I'm not sure what you mean by "cover." I've found that plastic tarps often help RVs rot even faster then when left uncovered. A genuine canvas breathes and works better. But I built a pole barn to park mine in. I've had it with fixing rot.

You will likely find that even the walls that feel solid will have thin plywood that is water-logged. When wood is completely soaked - it rots very slowly but weighs a lot. when it starts to dry a little and some air gets in -is when it really starts to rot fast. I just re-did the walls and roof on mine - and also the floor on the cab-over section. Never again (I hope).

RV walls in these older rigs are bad enough even if IN a barn. Once moisture gets in the walls - it is pretty much trapped forever. Unlike walls on a house -there is no ventilation to insulation and/or wood can dry out.

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My 91 Warrior looked a lot like yours. I vacuumed out all the peeling wood. Used Great Stuff foam to seal holes to the outside. Laid fiberglass cloth across the area, overlapping the remaining good wood by at least three inches. U-shaped around the cab opening. Poured cups of resin over the entire area. The resin sealed up all the remaining wood and fiberglass into a solid composite.

Added a layer of plywood over the entire area to distribute the load. The plywood goes from the metal angles on each side. Two pieces so that the cab area is covered but I can move one over the other to open up below - a feature that I almost never use.

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I'm not sure what you mean by "cover." I've found that plastic tarps often help RVs rot even faster then when left uncovered. A genuine canvas breathes and works better. But I built a pole barn to park mine in. I've had it with fixing rot.

Would love to have a pole barn, or even a basic carport, to keep this thing out of the elements! Too many projects right now and not enough time/$$.

The cover I was referring to was in that Amazon link: http://www.amazon.co...1528360_TE_dp_1

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My 91 Warrior looked a lot like yours. I vacuumed out all the peeling wood. Used Great Stuff foam to seal holes to the outside. Laid fiberglass cloth across the area, overlapping the remaining good wood by at least three inches. U-shaped around the cab opening. Poured cups of resin over the entire area. The resin sealed up all the remaining wood and fiberglass into a solid composite.

Added a layer of plywood over the entire area to distribute the load. The plywood goes from the metal angles on each side. Two pieces so that the cab area is covered but I can move one over the other to open up below - a feature that I almost never use.

Thanks for the input. I hadn't really considered the fiberglass cloth/resin option—I've got a table-saw, chop-saw, jig saw, etc and have some carpentry experience so will probably go that route. (I'm also crazy about this little gizmo.)

Sounds like you didn't make the half-circle cutout in your final plywood pieces. Any particular reason why?

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typical Toyota damage,

I have this,

I ripped out all the wet stuff including the open cell insulation.

I installed a cover on top if the fan so I could keep it wide open.

I keep a window cracked half inch and keep the fan vent wide open. No rain gets in through the fan vent. but some water soaks in through the leaks.

But with the fan vent open the inside dries in a day after the rain and it does NOT smell any inside the camper.

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Mine did not come with a center section cushion, just a couple of old cushions and a piece of wood. I put in a futon mattress, which I can fold over and slide the 20" plywood piece forward. Really haven't needed to do that. The bunk is just too handy as temporary storage.

The camper was also missing part of the front driver corner of the loft, which had been covered with metal tape. I had to pull off the aluminum gunnel, beat it into shape before placing back. Made L shaped fiberglass repairs to the outside corner. Filled inside corner with great stuff. Added Bondo filler to even out the fiberglass.

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Ctgriffi,

You're probably going to have to rebuild that rotted area. You can try all the band aid fixes mentioned but unless you remove all of the rot, the rot will just continue on to any of the new wood you might add.This is a pain of a job to do, but not particularly technical. All of the new wood can be found at most any lumber yard and, if you use epoxy glue, the joints you make with the new wood to the old will probably be stronger than the original construction. Just go slowly when removing rot and try to document everything with photos so you know how to put everything back together.

I rebuilt my cabover area a while back and I can send you some photos if you'd like. Send me a private message and I'll send you the pictures.

John

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I read your post and thought how lucky I am to have a leak free unit. No rot, no delamination, no leaks. I am out doing a bit of work and under the sink behind th heater it's WET with a bit of rot. Sink leaking? Nope there has not been any water in that unit since I brought it home the beginning of the year. There has been a lot of rain 5" one day, so it found a way in and from the looks of things it found the way along time ago.

This is great, I really needed one more project : ( Jim SW FL

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Ctgriffi,

You're probably going to have to rebuild that rotted area. You can try all the band aid fixes mentioned but unless you remove all of the rot, the rot will just continue on to any of the new wood you might add.This is a pain of a job to do, but not particularly technical. All of the new wood can be found at most any lumber yard and, if you use epoxy glue, the joints you make with the new wood to the old will probably be stronger than the original construction. Just go slowly when removing rot and try to document everything with photos so you know how to put everything back together.

I rebuilt my cabover area a while back and I can send you some photos if you'd like. Send me a private message and I'll send you the pictures.

John

I agree about wanting to do the job right, no band-aids. Sent you a PM. Thanks

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I read your post and thought how lucky I am to have a leak free unit. No rot, no delamination, no leaks. I am out doing a bit of work and under the sink behind th heater it's WET with a bit of rot. Sink leaking? Nope there has not been any water in that unit since I brought it home the beginning of the year. There has been a lot of rain 5" one day, so it found a way in and from the looks of things it found the way along time ago.

This is great, I really needed one more project : ( Jim SW FL

Yeah, I know how it feels, obviously. I thought I had a "leak free" unit too. I still made sure to always keep it covered when parked at the house, to no avail.

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Just reading some of this is going to give me nightmares tonight. I rebuilt the front berth on mine but the biggest mistake was not going over the outside with a fine tooth comb to seal it up tight. My Itasca is aluminum top and sides where the newer ones are fiberglass sides. From what I can figure, it seems the berth section in this type of RV is prone to a lot of flex. between sleeping in it and driving around, it seems to me like a week point all around.

This year I went up top and went over it completely. Every roof vent and cover was replaced. The nuclear option for me was to liquid EDPM the roof. The berth windows have been gone over. The old lap sealant removed and replaced. I also had pin holes galore up top that were covered over and hidden by roof coating that wore out. Add to that it had been badly repaired from a couple minor accidents front and rear. The bondo repairs to aluminum didn't hold because they were not done properly. I bandaid repaired all of it when I did the berth but then chased little leaks for 3 years.

This year it is sealed up solid and I am not stressing everytime it rains. Wish I had spent half as much energy fixing the roof as I did the berth when I first got it. Live and learn I guess.

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In watching your repair of the roof, I had a thought, OH OH. I do not need to redo my roof at this time, but would look into putting 1 or 2" of foam on the roof and then covering with rubber roofing.

Not sure if this is possible/practicle but after touching my ceiling with the AC on, it really needs something. My last motorhome was an MCI 5C Saudi Model. It was built for service in Saudi Arabia and had a dual roof. A second roof about 1 1/2" higher than the roof and open to air flowing through.

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In watching your repair of the roof, I had a thought, OH OH. I do not need to redo my roof at this time, but would look into putting 1 or 2" of foam on the roof and then covering with rubber roofing.

Not sure if this is possible/practicle but after touching my ceiling with the AC on, it really needs something. My last motorhome was an MCI 5C Saudi Model. It was built for service in Saudi Arabia and had a dual roof. A second roof about 1 1/2" higher than the roof and open to air flowing through.

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The biggest challenge is bonding the foam to the aluminum. Glue & screws likely. Thin luan to top it off along with rounded wood along the front, back and sides. The water based adhesives will have no issues bonding to the wood on top. Standard edge strips to secure it. The vent pipes on mine were long enough that the foam wouldn't have created a problem for the vent covers. RV AC and Vents are designed for thicker roofs than these toyotas. The new ones I put in required I cut the trim peices almost flush and they would accomidate a 2x4 framed roof.

Not a project I am looking to take on as mine was enough work to just seal up but see the merit to it where you live.

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Around here there are companies that spray foam the exterior of mobile homes and workshops. I think 2" of spray on and a layer of Rhino Liner should do the trick

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Update: Discovered that the cover I was using had a huge hole on the top, invisible from below; must've torn when I was struggling to put it on three months ago. We had several extremely hard rains this summer, so no wonder...

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  • 2 weeks later...

When you rebuilt the cabover how did you secure the new plywood? I'm preparing to remove the two front windows and attempt to fiberglass them in permanently solving the leaks! I haven't done fiberglass work before and I'm sure it's not going to go smoothly but anything will be better than what I have now. I just ordered $250 in materials this afternoon and it should be here by the middle of next week. Any advice to a beginner? I've ordered the Totalboat 5:1 epoxy kit and the Totalboat waxed gelcoat. After all of my research I believe my goal is to apply several coats of gelcoat while it's tacky, let it cure and then resin / fiberglass layers after that.

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FLGA, I've been busy and haven't exactly figured that out yet myself (securing the new wood), although Dolphinite has some great pics available of his repair job. Once I decide what wood is bad vs usable, I plan to tie into existing material with epoxy and pocket holes screws. My Warrior has a large angle piece of metal on each side of the cabover bed, joining the sides to the bed platform, and there are two other long metal pieces that join the exterior skin together, right above the windshield—all of that metal is rusty and nasty, so my first step will be wire-brushing/priming/painting the hardware.

But, maybe your question was directed at someone else...?

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In researching this I found that rot is a fungi (there is a fungus among us) which needs to be eliminated. On mine I was able to remove all rot except a small spot which I treated with antifreeze. I would expound on how to do it, but do not know what I am doing! So a little Googling if you are interested.

Jim

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As soon as the fiberglass mat comes in I will just be attempting to have at it. I will let everyone know how it goes. I anticipate doing it this weekend. I also bought some ribbon caulk / tape to reseal the rest of the windows in the camper.

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  • 2 months later...

I've been putting off my repair/rebuild project for some time, waiting for the unlikely combination of time/money to arrive. Due to a surprising (and very unwelcome) company layoff, I suddenly find myself with plenty of time, so I'm moving ahead and doing what I can with whatever materials I have handy.

I wire-brushed and sanded these pieces today, cleaned them up, and am priming/painting. The angle pieces are steel and join the bed foundation to the sidewalls. The other two pieces are aluminum and screw together to join the upper/lower fiberglass skin, at the roof of the cab.

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I have never had an RV but bought a Toyota dolphin, 1992 for 2500, the RV place I took it to said the floor is completely

Rotted tandem that the cost would be thousands, can I fix it myself

If you've got enough time, money, and carpentry skills, I would say it's possible. I suggest you start a new thread and begin posting all your questions—lots of knowledgeable people around here that will point you in the right direction. :)

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I have never had an RV but bought a Toyota dolphin, 1992 for 2500, the RV place I took it to said the floor is completely

Rotted tandem that the cost would be thousands, can I fix it myself

There is an elderly gentleman near me with a 90's Toy who was told he needed a new floor. If it was mine I would not replace it! His floor is not rotten but soft. The floor is thin luan on the outside covered with foam sheets and gone over with 1/2" (might not even be 1/2"?) flake-board, far from being a substantial floor! I would want a 2nd opinion from a Toy owner.

Jim

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  • 3 months later...

Finally getting close to the point where I can really get into the cabover repair... Got a materials question: I came across some nice, straight 5/4 cedar boards at a local big box store, and I was considering using some of that in my rebuild. Obviously, the water-resistance and light weight of cedar are great benefits, but is it strong enough for structural work? Thoughts?

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7 hours ago, Ctgriffi said:

Finally getting close to the point where I can really get into the cabover repair... Got a materials question: I came across some nice, straight 5/4 cedar boards at a local big box store, and I was considering using some of that in my rebuild. Obviously, the water-resistance and light weight of cedar are great benefits, but is it strong enough for structural work? Thoughts?

Cedar is variable in strength plus it is not the best wood for fastener holding being as it is a soft wood. The cantilevered structure of the overcab framing  is prone to a lot more stress at the joins than any other part of the structure on your motorhome so you do need to have a material with a lot of fastener holding strength. Your most reliable bet for strength versus weight in the framing wood is to use Doug Fir. White Oak would be stronger but also considerably heavier so the Doug Fir is a good compromise of weight versus strength.

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14 hours ago, snail powered said:

The cantilevered structure of the overcab framing  is prone to a lot more stress at the joins than any other part of the structure...

Thank you, SP, for the insight; Douglas Fir does sound like my best bet. The comment about the "cantilevered structure" stood out to me because it kind of helps me get my head around just how the upper berth is able to support weight, out beyond the roof of the cab (something I was a little fuzzy on before). The dilemma becomes, then: how to best tie into any existing good wood immediately over the driver/passenger area in such a way that, when a few hundred pounds is applied forward of the cab, the joint doesn't split apart. (Epoxy + pocket hole screws + scarf-joints will do the trick, I hope.)

Another related question: The existing bottom structure of my cabover appears to be an open grid of 1x6s (laid flat of course), with insulating foam board filling the gaps in the grid. Most of that material is gone/ruined, and I'm wondering... when I replace those boards, do they need to be glued to the fiberglass skin underneath them, or can they just sit on top?

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You can use metal strapping across joins to help increase the strength in various areas of the construction. That will help tie it back into the main structure of the coach.

Yes you should bond the wood to the fiberglass skin. Stress skin panel is a method of building where the framing and the skin are bonded together resulting in a light weight and strong structure that also has some flexibility to it. Not just the boards on the bottom but also the other areas should also be bonded. Use an adhesive that is rated to stick to fiberglass and wood spreading in a nice even layer all across the timber.

Over the years in this forum there have been quite a few rebuilds by forum members of wood framed overcabs. You can browse through the photo albums and thread postings to find them.

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White Cedar is naturally rot resistant but as the other poster mentioned - soft and wants to split easy.  White Oak is the #1 choice if you want natural rot resistance and strength.  Douglas Fir is also plenty strong but not rot resistant.  Southern Yellow Pine is also extremely strong and this is what is often used to make rot-resistant pressure-treated wood.  Problem is finding any that is dry and not going to warp.

I re-did my cab with White Oak supports. Nothing better IF you can find it. It is a local product here and often used in boat building.

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  • 1 month later...

Small update: Still working at this, just don't have much time. I'm trying to make sure the roof and all is sealed well before I do much cabover reconstruction. Really wish I had a covered place to park this thing; stressful trying to deal with tarps/covers, watching the weather forecast like a hawk, etc!

Anyway, I've heard a lot of people say the front window is often a major source of moisture, so I pulled it out last week for an inspection. I was amazed at how well the window was sealed and by the condition of the surrounding framing—hardly any signs of water damage, when I was expecting a serious mess. So, cleaned it up real well, reinstalled the window with new butyl tape. Guess my water intrusion problems are coming from somewhere else.

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  • 1 month later...

I see my thread is now about 10 months old... and I'm still working away on this same problem. I've replaced all the clearance lights, resealed front and rear roof seams, resealed and reinstalled the front window, and I just finished replacing the large fridge vent on the roof. I think the roof is in pretty good shape (I've not seen any of the tiny pinholes in the aluminum roof that others have mentioned.). So, anyway, moving forward on the cabover rebuild and am well into the demo stage now, ripping everything out, down to bare fiberglass skin. Not my favorite thing, for sure. I look forward to having a nice clean slate to work with again soon; that's the fun part for me. 

Meanwhile, it's been raining and raining for weeks now (wettest, weirdest summer I can remember), and I'm a little concerned about another water-related problem:  While I haven't seen any moisture in the cabover area, I did come across a lot of moisture in the footwell of the cab today. What's the likely source? Anybody else dealt with this in the Toyota cab?

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I can relate, I am still working on various problems and reworking some of the ones I already fixed.  Some day I am going to swap this thing for a golf cart... but not today.   Jim

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I feel like I finally turned a corner on this cabover rebuild—got to the place where I was actually able to start adding new material this past weekend, and it feels great! Still a ways to go, but I feel like I can get my arms around the problem now, and I know what needs to be done.

I also was able identify a very likely source for much of my water intrusion: on one side of the cabover, the corner trim was loose and poorly sealed, right where it makes the lower turn and runs across the underside. New wood inside of that area will allow me to secure the trim and get it sealed up.

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  • 4 weeks later...

Can anybody tell me, for certain, which side of this channel faces to the front of the vehicle? This is the underside piece that joins the fiberglass skin, right in front of cab windshield. 

image.jpg

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