Fixing roof

[KIS_Man]

I have a 2006 Palomina Maverick 1000 truck camper. I have some small areas of roof rot around the sky light. I have very carefully laid the rubber roof back exposing the rot. At this point I have not been able to determine the structure of the roof frame. It appears to me the plywood might be glued to the styroforam insulation. Can anyone give me the correct procedure to replace the plywood.
thanks

[KIS_Man]

Thanks to darsben and Joe417. My wood was to far gone to darsben's fix, but it would have saved time. my TC was just like Joe417's. I will glue the wood patch in this am. My concern is weakening the roof. All though the roof was weakened by the rotten wood.

Thanks so much for your help.

[Joe417]

I had the same issues with a 2003 maverick 8801. I had 3 areas affected, 10" to 12" x 24" on each front corner and around the bath sky light. It's a great design and really sturdy (once you get it repaired). The repairs are easy.

Roof was 1/4" plywood glued onto polystyrene forming a stress-skin panel. They are very strong. The roof had a perimeter frame and only 2 cross members, all of about 1 1/2" wood. All the holes in the roof also had 1 1/2" framing. Locations that required screws where there was no framing (such as front cap)had a thin sheet of metal bonded under the plywood.

I dug out all the (while it was still wet) damp wood only, leaving the last ply in some areas as it was securely bonded to the Polystyrene. Let it dry completely. I probably replaced 18 square feet. I cut 1/4" panels to fit the areas affected and bonded them in with polyurethane glue (Gorilla glue)(May be a cheaper brand such as Elmers). It is a moisture cured glue so doesn't need air to cure. It will foam up and fill voids when it combines with moisture.

You'll need to stack something heavy on the plywood for it to cure as the glue will foam up and raise the wood up. Once the wood was repaired I taped all the seams with duct tape and put new rubber on and re-installed everything.

Note 1. If you don't want to replace the rubber, cover it up with something that will peel off the glue when your ready to glue it back down. All the damaged wood pieces will stick to it and are hard to remove from it. Not an issue if you replace the all the rubber.

Note 2. Peel back the rubber and give time to dry. The rubber holds water both ways.

Note 3. When gluing, spread the glue evenly on the roof and mist the replacement wood
panel with water.

Note 4. Wear good rubber gloves or you will be wearing the glue for a while.

I was planning on posting the whole job with pictures but didn't find the time. If you have more questions just ask.

Also, picked up all my supplies in your neighbor hood. Bontrager's just north of Shipshewana.

Maybe this will get you going.

Edit.. I thought of something else. The paneling on the ceiling between the skylight and vent was also de-laminated. The plastic ceiling surface was in good shape. I very carefully dug the wet wood out without damaging the plastic coating. One ply of the interior paneling was still bonded the the plastic. Carefully slid in a new piece of plywood and clamped till the polyurethane cured. You could not tell that it had ever been wet.

good luck.

[darsben]

I would think about using a product called GIT ROT made for rotted marine plywood.
I have no practical experience using it on a RV roof but I have used it on wooden boats with good results