Something rotten in River City..Andy Help me!

[Trex]

The last three days I have been gutting the interior of my 72/31' international. Today I removed the front gaucho and the carpet behind the gaucho....crap! There is dry rot in the plywood below the front windows and side windows, total of four small areas in the plywood are rotted all the way thru to the insulation!


My question is… do I remove the entire section of plywood, or do I cut out the dry rot and patch? Please help me do the right thing. Hope my photo is not to big! I am still trying to learn how to post threads

[wasagachris]

Rex there will be more damage to the plywood under the edge of the shell. I would replace the entire section of plywood. The sections across the front are where the shell is held down to the frame. This is the main connection point from the shell to the frame. Solid wood is needed there for proper support and a good solid connection. This section can be easily replaced without shell removal. It will however require removal of the lower sections of interior wall to access the bolts holding the shell to the frame. Be sure you carefully inspect the rear section of floor as well. There should be more damage there. BTW that is not dry rot. You have leaks causing the floor to rot. Trust me I know. Mine was exactly the same.

[barts]

You want to replace the rotted wood.... and fix the leaks that caused the rot, of course!

Small sections of plywood are readily replaced, although it is a bit fiddly. You want to cut out the damaged sections, leaving nice straight edges to simplify fitting the replacement piece. Removing the damaged sections from the C channel may require loosening the bottom of the interior skin; there may be bolts or screws into the plywood from the top of the C channel. You'll want to use butt blocks screwed and glued - Gorilla glue or other polyurethanes work well - underneath around the perimeter of the hole to support the replacement piece. The amount of overlap should be several inches as this will insure that the floor has a continuous curvature. I use #10 laminating screws to hold things together while the glue dries.... the replacement piece should be glued and screwed as well.

Depending on the floor covering you're going to use, you may need to fill any remaining gaps at the seams, etc; I use thickened boat building epoxy for this because I'm used to that material.

The repair is not difficult, but removing all the damaged section of plywood can require some patience, ingenuity, and chisels, jig saw blades held in vice grips, etc.

Good luck -

- Bart

[wahoonc]

Replace the entire section. There are some pictures in my gallery where I did the front section only. Turns out the hold down bolts for the shell to the frame were basically missing. One was completely gone, the other barely holding on. The visible rot area was very small. Make sure you caulk the tops of the windows and if you have a window guard that you reseal the fasteners on it too.

Aaron

[AIR-Quarius]

REplace the whole enchilada.

[Splitrock]

Originally Posted by Rex Crabtree

The last three days I have been gutting the interior of my 72/31' international. Today I removed the front gaucho and the carpet behind the gaucho....crap! There is dry rot in the plywood below the front windows and side windows, total of four small areas in the plywood are rotted all the way thru to the insulation! Attachment 113180

Have you checked the rear yet?

Gary

[thecatsandi]

Remove the entire section and treat both sides with a sealant that is non reactive with metal.

[Inland RV Center, In]

Originally Posted by Rex Crabtree

The last three days I have been gutting the interior of my 72/31' international. Today I removed the front gaucho and the carpet behind the gaucho....crap! There is dry rot in the plywood below the front windows and side windows, total of four small areas in the plywood are rotted all the way thru to the insulation!


My question is… do I remove the entire section of plywood, or do I cut out the dry rot and patch? Please help me do the right thing. Hope my photo is not to big! I am still trying to learn how to post threads



Attachment 113180

The floor is a part of the semi-monocoque construction. Sectioning it weakens that construction.

Replace the entire front part of the floor.

Yes, it's more work, but the rewards will be even greater, in time.

However, before you jump in, correct all the water leaks first. Then you have assured yourself that when the floor is replaced, it's done. Sealing the wing windows, vista view window and stack windows, is an easy job, using Vulkem sealer.

Check out the rear end as well, for a bad floor.

If it hasn't been done, replace all the exterior gaskets, including those for the sewer vent pipe covers as well. Some of the gaskets now have upgrades that are far superior.

Andy

[Trex]

To me it looks like the water damage happened many years ago, because she had been painted silver, 10 or 15 years ago, and I can see sealant had been added before it was painted, (paint is pealing away from sealant along the top of the windows). And it looks like it has been dry for many years, (in the rotted areas). But the rainy season is coming to Northern California soon, so if it’s still leaking I will find out soon.

I do plan to reseal the outside, and I plan to replace the front sheet of plywood. Monday, I will remove the inside skin, so I can get to the screws holding down the front of the trailer walls.

Thanks again guys for your advise and support….Trex

[Inland RV Center, In]

Originally Posted by Rex Crabtree

To me it looks like the water damage happened many years ago, because she had been painted silver, 10 or 15 years ago, and I can see sealant had been added before it was painted, (paint is pealing away from sealant along the top of the windows). And it looks like it has been dry for many years, (in the rotted areas). But the rainy season is coming to Northern California soon, so if it’s still leaking I will find out soon.

I do plan to reseal the outside, and I plan to replace the front sheet of plywood. Monday, I will remove the inside skin, so I can get to the screws holding down the front of the trailer walls.

Thanks again guys for your advise and support….Trex

If the floor is not rotten, and still has some lif to it, then you can repair it with a very slow setting of fiberglass resin.

Andy

[Trex]

Today I removed the interior wall above the rot.... I see that the bots are bent over so they don't loosen over time. Q. What is the best tool/saw to use to cut old bots off? And what is the best type of bot/screw should I use to replace the one's that I cut out?

[68 TWind]

For the ones you can access on the straight section on wall, I used a 4 in. grinder with a thin cut off blade when I replaced all the rear wood in my TW. You must be careful, eye protection and don't hit the exterior skin. It makes short work of the bolts. On the bolts that are were not easily reached by the angle grinder I used a dremel tool with a cut off wheel. The vibrating type saws ( Multimaster, etc) are great to clean the wood out of the channel but I tried several different blades and none would cut through the bolts.

[barts]

If you cannot reach the bolt w/ the angle head grinder/cut-off wheel, a metal cutting jigsaw blade held in vice grips will make short work of the bolts - there are only a handful of 3/8" bolts - most are 1/4" or smaller (#12). Replace them with stainless ones, with self-locking nuts.

- Bart

[Cracker]

In some cases I believe water damage comes from condensation. I stored my original Airstream briefcase in the curbside compartment under the couch arm and, when I was prepping the AS the first of the summer, I found all of the papers in the briefcase to be soaking wet! There were no descernible leaks anywhere, however, due to the position of the AS in my driveway over the winter, this compartment went from 10 deg below at night to being directly heated by the sun for the better part of the day. I would guess that, on a 25 deg day, thanks to the insulation afforded by the couch, the temperature therein probably went up to near 70 deg - and whatever humidity that was available collected in the briefcase! I would suspect that this phenomena occurs elsewhere in the trailer where there are enclosed exterior compartments. With that in mind, this winter I plan to open every compartment I can to prevent differential temperatures. For the record, the briefcase was not in contact with the inner shell of the trailer, although the couch arm above it was, and there was absolutely no sign of moisture anywhere else in the carpeted compartment. As for the plywood under the carpet I can only hope that it remains undamaged.

[Trex]

Today I got most of the subfloor/plywood removed... I am having some problems removing the 4 bolts out of the very front of the plywood/frame. I did buy a 4" grinder this morning at Home Depot. Works great.

Anyway, once I get the last of the plywood and bolts out. How do you I insert the new section of plywood in one piece, or do I cut into two sections and insert. How do I bolt down the plywood without taking out the skin under the frame? I need more good advise!

Here is a couple of photos from today…..

[68 TWind]

There is not way to insert a whole piece, because of the curve and the channel it won't go in. What I did when I replaced the rear sheet and what most folks do it to split the new piece where the seam will be on top of the frame rail. Couple of things to consider.
1) Put a slight bevel on the edges that go into the channel, it will really ease the install.
To install it you can lay a 2x4 on the inside edge of the new piece and tap it in till it drops in place.
2) I coated and outside 6 inches top and bottom of the new wood with boat builders epoxy resin to seal and protect from any future damage. I also put several coats of marine spar urethane on the rest of the wood, but this was in the rear and under the bath.
3) You MUST drop the belly pan for banana wrap to replace the bolts in the channel. They hold the front of the trailer on the frame, you MUST replace them.
4) For other areas if you don't have access you can use self tapping floor bolts. VTS has them. HD has them now as well if you need them in a hurry. Elevator bolts are better but these work ok but NOT in the channel area.

[Trex]

Removed the rest of the bolts today cleaned the area and got some cardboard and made templets so I can cut the plywood. I plan to get epoxy resin seal and seal/treat plywood before I install. The plywood is marine grade... $82 bucks a sheet, May be overkill? Plan to use deck paint for all the subfloor. Also finding many holes in skin along the subfloor line, so I need to seal inside and out with Vulken???
Hopefully I can get that stuff at the RV store across the freeway from my house.....Trex

[HiHoAgRV]

Oh boy...

THAT Looks Familar...

http://www.airforums.com/forums/f205...tml#post734787

[Trex]

Installed the new floor today... I painted plywood with trailer roof paint. Using epoxy to fill holes around the elevator bolts and two small water damaged areas in the corners of the 2nd sheet of plywood. Looks like it going to work okay. I will bolt down the front wall tomorrow.

See if I can upload photos....

[Trex]

This may sound a little crazy… but I am thinking about using diamond plate aluminum, and screw and glue to my sub-floor under the refrigerator and the full ten feet under my sink, stove/oven, and counter space on the road side. If I cut a 4x8’ sheet in half I should have enough to cover….. The twin beds are gone and plan to built custom cabinets and diner seating in place of the beds. Has anyone out there tried this?