1991 34' Floor water damaged in rear.

[potatoes]

I have had my 1991 34' Excella for about two weeks & decided to replace the carpet & upholstery. Tore carpet up tonight & floor is rotted in the very rear about 2' in from the rear hatch not being sealed tightly. Is this an easy fix? I also want to use laminate in the entry & kitchen area to the bedroom, but the floor doesn't seem quite level around the wardrobe area. Will that affect the laminate? It's not really unlevel, just seems like it is flat & then slopes towards the wardrobe side...

[malconium]

It sounds like the type of fix where you cut out the rotten part and patch in a new piece of plywood. You can use strips of plywood maybe 4 to 6 inches wide under the edges of the hole to create support for the patch where it does not sit on the metal frame and to tie it together with the rest of the floor. Typically you would attach the strips to the main part of the floor with waterproof wood glue and screws from above (such as decking screws). You can then add glue to the part where the patch sits, add the patch and screw it into place. The wood screws mostly just hold things while the glue dries. Screw spacing could be something like 6" apart. You can use self-drilling/self-taping screws to attach any part of the patch that does sit on metal to the metal.

Is there good plywood all the way around the rotted area?

Malcolm

[87MH]

Originally Posted by potatoes

.... floor is rotted in the very rear about 2' in from the rear hatch not being sealed tightly. Is this an easy fix? ...

How "easy" it is really depends on how far the rot has progressed. You may want to research a floor repair by "Barking Spider", he documented his "fix" for some rot he found in the front, and revealed a horror story of a comedy of errors when he attempted to have it "fixed" by a couple of AS service centers. He ended up doing it himself.

If the rot has progressed under the edges of the floor, to where the floor, frame, and shell come together, the repair could well be complicated. The floor, shell, and frame work together to form the strength of the trailer, and the joining of these three elements must not be compromised.

Unfortunately, as the wooden floor is sandwiched between the frame and the shell (via a "C" channel), a rotten floor in this area will may well lead to a more catastrophic failure. - Do a search on "Rear End Separation" and "Rear End Sag".

Any serious pre-purchase inspection should include a thorough inspection of the entire floor/frame/shell perimeter, to the extent that considerable interior disassembly should be undertaken. This will be expensive, but not nearly as expensive as a proper repair to replace any rotted floor or rusted frame. - Do a search on "Full Monty".

On my 31' Sovereign I did a similar repair - I found the center section of the floor at the very rear of the unit was bad - even though there was very little indication of rot on the surface. As I tore into it, I found more and more hidden damage. The rear is a critical joining area, as the two main frames and three stringers are joined to the shell across the very rear through the "C" channel and plywood floor with bolts. The lack of a sound floor in this area creates a situation where vibration and road stresses are allowed to amplify due to the rear overhang, and possibly allow an even quicker and more destructive deterioration. The difficult part of a fix for floor rot under the "C" channel is getting to it - to properly repair and replace the wood floor in the perimeter mating area the interior panels AND the belly pan should be removed. I extended the "under floor patch" area by quite a bit, and installed screws about every 1 1/2" with a double row (four rows total) in the area of the join - my repair went all of the way across the back where possibly the highest stresses of the monocoque construction are located.

To specifically answer your question on floor repair, below is an excerpt from the AS manual from 1978. The cost (and complexity) of the repair really depends on whether or not the rot has progressed to the area under the "C" channel.

[87MH]

Originally Posted by 87MH

How "easy" it is really depends on how far the rot has progressed. You may want to research a floor repair by "Barking Spider"..l.

"Barkingspider" - REAR repair

http://www.airforums.com/forum...ad.php?t=11903

[potatoes]

Thanks for your replies! I will try to post a picture later today so you can see the extent of the rot. It basically covers the whole rear width, but not quite to the sides and forward about 18"-2'. I tapped the rotted spot with my pliers as I was pulling carpet pad staples out and they went right through the floor. Also, the city water hookup is also next to this area of rot and their is a water stain from a leak at some point but not soft damage. To cover all of the possible damage I think I need to replace about from the rear forward about 3'. I am thankful that I found this forum before I got into this remodel by myself. There is an amazing amout of knowledge & experience here!

[bake315]

Originally Posted by potatoes

Thanks for your replies! I will try to post a picture later today so you can see the extent of the rot. It basically covers the whole rear width, but not quite to the sides and forward about 18"-2'. I tapped the rotted spot with my pliers as I was pulling carpet pad staples out and they went right through the floor. Also, the city water hookup is also next to this area of rot and their is a water stain from a leak at some point but not soft damage. To cover all of the possible damage I think I need to replace about from the rear forward about 3'. I am thankful that I found this forum before I got into this remodel by myself. There is an amazing amout of knowledge & experience here!

Is your floor OSB, or regular plywood?

Reason I ask is that I replaced the carpet throughout my 34' last winter, and noted that the flooring is 4x8 sheets of plywood fastened to the frame cross-wise throughout the entire trailer. If yours is like mine, I'd think it might be possible to replace that entire section as one piece. I would recommend stabilizing the frame from beneath if you do this, though.

Probably would be a good time to get in there and replace waterlogged insulation in the belly pan, too.

[potatoes]

My floor is the OSB and it is one solid sheet from front to back. I tried to look for the seams and never found one which surprised me. It looks like I need to replace at least 3' maybe 4' to get rid of all the bad stuff for sure.

[bake315]

Originally Posted by potatoes

My floor is the OSB and it is one solid sheet from front to back. I tried to look for the seams and never found one which surprised me. It looks like I need to replace at least 3' maybe 4' to get rid of all the bad stuff for sure.

It isn't unusual that there are no seams with OSB since they can manufacture it to whatever width/length they want. This is just me, but given that it's such a large area of damage I'd cut out a section as far in as you have to, and then go all the way across. Fortunately there isn't a lot back there on the 34's that is particularly heavy, like tanks and such. I can't imagine being able to put enough weight in the bumper compartment to make any difference. The fact that mine was built with individual sections would seem to indicate that manufacturing costs had more to do with it than strength. I'd bolster the frame, cut out the bad, fasten the new piece of OSB (or comparable sheet of plywood)securely to frame and shell, and call 'er fixed. Just make sure you have that city water supply leak fixed first, though!

[potatoes]

I plan to get the materials together this weekend and possibly start the repair. I've read through several posts about repairing floors and feel like I should be able to make the proper repair to the floor. The city water looks like the PO used a short piece of clear hose with hose clamps that could be the problem there. I'll get started and post my progress. Thanks for you help and suggestions.

[PizzaChop]

Dennis pretty much said it all (good job, Dennis).

The actual flooring replacement isn't so bad, it's the disassembly and reassembly that stinks. (Remove rear belt line, belly wrap, banana wrap, etc.)

I would definitely replace at least a full sheet of plywood (4'x8') considering the trouble it takes. But on positive note, it will give you a chance to inspect, repair (if necessary), and paint (reseal) the frame as well as replace the insulation.

It's not a particularly expensive repair (less than $100 in materials) unless you pay someone else to do it (I've read where someone was charged close to $2K for this, and they didn't even replace the whole sheet.).

I just did it again (2nd year in a row, different trailer) recently and have posted some pics. (If you look back at all my pics, you'll see the floor job I did last year on the '72 Overlander.)

You want to be sure that you have the rear skin to frame area sealed really good to prevent future water damage. (Of course, I don't really know what a 90s Airstream looks like compared to my 73 model)

I would remove the belly pan and banana wrap before cutting out the floor.

When cutting out existing floor, keep it together as much as possible to use as a template. What worked best for me is to use a reciprocating saw to cut out the floor about 1-2" from wall and then cut bolts off around the perimeter (as they will most likely be rusted) and remove the 3-4" extending under the floor). The reciprocating saw has a smaller blade width which helps in making your template. (both times I superimposed fragments of floor onto $10 sheet of 1/4"" luan to use as a template. Definitely $10 well spent as it's a lot easier to maneuver than 3/4" when checking for fit.)

[potatoes]

Seems as if my leaks might be coming from the beltline (if that is what the trim with the wide blue insert is) area in the rear and maybe on the drivers side just ahead of rear. Is that an area that could cause leaks to the interior if the sealant is not up to par on that beltline?

[dinoburb]

Hi!

This is a note from a science teacher; please be careful when working in the underbelly of your AS. The waste products from our furry little mouse friends carry the Hanta Virus. This disease has been around since the Korean War - where it got its name. I have inclused a link to a site in Washington State, but there are numerous sites providing information on this deadly virus.

Click here:
http://www.doh.wa.gov/topics/hanta.htm

Hope this helps.

Take extra care!