PO Sub-floor cover up

[continentsco]

Hey guys,

We bought our first AS last week. Drove 18 hours out of 28, to MS and back home to Houston with our 1985, two door, Excella. We are very happy with it but does need some work.

The person we bought it from flips trailers and even though that is a red flag to some people, we still went ahead and purchased it. He went ahead and installed new 'subfloor' on top of the actual subfloor as it was 'bumpy' (we knew this going in). For our budget, we weren't going to find an AS that didn't need something major to be fixed. Axles looked alright so it had to be the floor.

Last night we spent several hours removing the 3/4 pressed board topping that he had put down and bolted into the frame through the original floor. He had put it around the dinette and cabinets and not under everything. We got up 7 pieces but then got to the back bedroom - we have a center bath.

He has used so much liquid nails that we cannot get it up. He didn't use much on the other pieces so they came up easily but not on these which makes us think he is hiding something.

This picture is just some of the front of the airstream. You can see he patched some of the regular subfloor.

Here is a close up of a small rot spot by the battery compartments.

Here is the dreaded bedroom section that we couldn't get under.

We tried using a circular saw to cut it in pieces and pry up with a crowbar but it stunk the place out with a burning glue smell.

Who has thoughts? Do we just leave it and put flooring over the top? We can only pry from this one section as the rest go up against the wall and we can't get to any other side to put the crowbar under.

Suggestions would be awesome!



Here is our new baby!

[Al Boondy]

Unfortunately you should remove all the subfloor down to the frame and replace.
The plywood floor helps support the shell and since the PO spliced the plywood over the frame rails it is providing almost no support. It needs to cantilever over the frame rails in one piece.
A very nice trailer you have there, we'll worth the time to fix.

Congratulations and good luck!

[continentsco]

Originally Posted by Al Boondy

Unfortunately you should remove all the subfloor down to the frame and replace.
The plywood floor helps support the shell and since the PO spliced the plywood over the frame rails it is providing almost no support. It needs to cantilever over the frame rails in one piece.
A very nice trailer you have there, we'll worth the time to fix.

Congratulations and good luck!

Do you think that I should just take all lower interior skins off, unscrew the bolts, and then cut all wood into pieces and then slide out of the channel?

My issue with liquid nails would be pointless then as I'd cut through both layers with a circular saw and remove.

[Al Boondy]

The interior skin will have to be removed to access the bolts and the belly wraps under the trailer.
The PO probably notched the plywood around bolts and slid pieces in unless he removed skin.
The PO of my excella changed entire sub floor but notched around bolts and spliced plywood over rails.

You may be able to remove the plywood without access to bolts, but you will need access to put them back. Might as well remove skin now.

Before proceeding I would block trailer up nice and straight at several points along frame. The trailer flexes a lot more with inner skins removed.

[Al Boondy]

You can see here how the PO installed new plywood in pieces providing no strength to hold up the shell. I removed it and am glad that I did. Found a few outriggers that needed to be replaced and was able to rust proof and paint the frame.

[fj56]

Congrats on your purchase ...

The only reason an airstream , any year needs new flooring is because there is a water leakage problem...Covering the problem will not solve the problem...Identify the leak , address it , remove the original flooring replace with waterproof plywood , or non-porus material...Never use OSB plywood may be cheaper , but is junk..
Stephen , call if you would like .. 715-617-4099

Originally Posted by continentsco

Hey guys,

We bought our first AS last week. Drove 18 hours out of 28, to MS and back home to Houston with our 1985, two door, Excella. We are very happy with it but does need some work.

The person we bought it from flips trailers and even though that is a red flag to some people, we still went ahead and purchased it. He went ahead and installed new 'subfloor' on top of the actual subfloor as it was 'bumpy' (we knew this going in). For our budget, we weren't going to find an AS that didn't need something major to be fixed. Axles looked alright so it had to be the floor.

Last night we spent several hours removing the 3/4 pressed board topping that he had put down and bolted into the frame through the original floor. He had put it around the dinette and cabinets and not under everything. We got up 7 pieces but then got to the back bedroom - we have a center bath.

He has used so much liquid nails that we cannot get it up. He didn't use much on the other pieces so they came up easily but not on these which makes us think he is hiding something.

This picture is just some of the front of the airstream. You can see he patched some of the regular subfloor. Attachment 275444

Here is a close up of a small rot spot by the battery compartments. Attachment 275445

Here is the dreaded bedroom section that we couldn't get under. Attachment 275446

We tried using a circular saw to cut it in pieces and pry up with a crowbar but it stunk the place out with a burning glue smell. Attachment 275447

Who has thoughts? Do we just leave it and put flooring over the top? We can only pry from this one section as the rest go up against the wall and we can't get to any other side to put the crowbar under.

Suggestions would be awesome!

Attachment 275451

Here is our new baby!

[DavidsonOverlander]

It's big job to replace the full floor, but you'll be glad you did in the long run. It will give you a chance to make sure that the frame is okay, including the outriggers. On our '74 Sovereign almost every outrigger needed to be replaced or repaired. Removing the lower interior skins will also give you an idea of the condition of the insulation and whether there are any mouse nests.

[Belegedhel]

You are teetering on the edge of a monster project.

I would offer that yes, the floor most certainly has rotten spots in it, and that is why the PO covered it all up. In the places where you have been successful in pulling up his overlay, is the subfloor unterneath solid (at least for the most part)?

You have two main paths before you:
1) If there are some rotten spots, but they can be patched up, then this is by a mile your easier route. When I say "patch," I mean cutting out the rotten stuff, installing doublers around the perimeter of the patch, and putting in the patch flush with the existing subfloor. If you have a bunch or rot that extends under the wall, you will be pushed more toward (2) below. As mentioned above, any piece that extends under the wall and has a bolt going through it will need to have the bolt removed, again meaning more and more disassembly.

2) If large swaths of floor are rotten, and especially if you have a significant amount that is against/under the walls, then this may dictate that a complete floor replacement is the way to go. To do this, you will have to remove all the furnishings that limit your access to the lower interior skins, then the lower skins, the banana wraps, and at least part of the bellypan. Some people replace the floor with the shell in place, but I figure you are 90% of the way to a shell-off anyway, you might as well build the gantries and go for it. Makes all the repair work a lot easier.

So how to get the overlay up? Well this is heresy, and my perfectionist nature rebels against my even saying it, but if you can convince yourself that the actual subfloor has enough integrity, then maybe you just put the scabs back in place and think happy thoughts. Alternatively--time to start buying cheap disposable specialty tools:

http://www.harborfreight.com/42-in-l...per-62687.html

Get yourself a nice-sized air compressor while you are at it.

You might also take a 1/2" Forstner bit and just drill through the overlay next to the wall, on top of each outrigger all the way around the trailer. If you don't find rot, then it is good news--more of a patch job than a total replacement.

I just had another look at your pictures--the first two showing what appears to be plywood patches level with the original OSB subfloor. So it looks like there was a bunch of rot all along each side of the front (?) part of the trailer, and the PO cut the rotten stuff out and patched in the plywood. The huge unknown here is what he did with the bolts that go through the C-channel and into the ends of the outriggers. If he just cut slots in the wood and shoved it under the wall, then that is sub-optimal. Probably the only way to see what he did is to either see if you can remove the patch, or take off some banana wrap outside and look up under there to see what you can see.

You know, they say Airstream trailers are like onions: the more layers you peel away, the more you cry...

good luck!

good luck!

[continentsco]

Thanks everyone for your input. Here is where we are after tonight.

We first drilled holes into the bedroom floor with forstner bits to see what was underneath as we couldn't get the OSB up. After drilling through to the sub floor, we found plywood. That could have been good if the original sub floor was plywood but as you can see from the pictures above, it was OSB which means it has been patched - again, like the above pictures. I'll get to that again in a minute.


So after that we decided that we would remove the front, lower, interior skins as we knew there was a small rotten spot by the road side battery compartment. After two hours of drilling rivets and unscrewing every window attachment under the sun, we finally removed one interior skin and then proceeded to remove one of the two plywood patches done, we think by the person before the PO, to see the frame. Thankfully, the frame, although it has surface rust, looks in good shape.


What we found was lovely. The whole front left side around to almost where the dinette was, was rotten and the OSB had broken off during the leak and was in the U/C/J channel (whatever the appropriate channel letter is - 'I'll take a consonant please').



So. The next step from this point is, to continue to remove the entire living area skins all the way around under the window and round to the front door to see what level of damage is under there. First things first, is to fix the living area. Then we can look at the rear bedroom (this is where I pick up from earlier) to see if the same half done job is repeated in the rear. Which it probably is. Oh, the joy.

Small victories and small goals along the way.

[Belegedhel]

Ha! Silly me, thinking that the "repairer" would have actually put the subfloor patches under the walls instead of just leaving a strip of rotting wood there! And I though worst case would be that he shoved the patch in with slots where the bolts would fall. Well, it sounds like you know what to do next, ie., removing lower interior skins and dropping the banana wraps/wrapped belly skin so that you can get at both sides of the bolts. Even if you end up replacing the living area and bedroom floor entirely, it doesn't sound like you have a lot of cabinetry to tear out to do that, so it is a pain, but still not a shell-off. Make sure that any patches you install are thoroughly painted with some kind of sealant like polyurathane so that the next time they get wet, they don't disintegrate. Also, use a decent grade of plywood, not that OSB garbage.

good luck!

[continentsco]

Originally Posted by Belegedhel

Ha! Silly me, thinking that the "repairer" would have actually put the subfloor patches under the walls instead of just leaving a strip of rotting wood there! And I though worst case would be that he shoved the patch in with slots where the bolts would fall. Well, it sounds like you know what to do next, ie., removing lower interior skins and dropping the banana wraps/wrapped belly skin so that you can get at both sides of the bolts. Even if you end up replacing the living area and bedroom floor entirely, it doesn't sound like you have a lot of cabinetry to tear out to do that, so it is a pain, but still not a shell-off. Make sure that any patches you install are thoroughly painted with some kind of sealant like polyurathane so that the next time they get wet, they don't disintegrate. Also, use a decent grade of plywood, not that OSB garbage.

good luck!

My concern right now is that the C channel is bent in certain spots, nothing major, but enough that it is going to make sliding new wood in very tricky. Should I use a router bit on the edge of 3/4 marine grade plywood to take it down to 1/2 inch to make it easier to slide in?

The only real cabinetry is the kitchen and closets which are in really good shape and, from what we can see under it, the floor looks in decent shape there and is original. I don't want to touch that unless I have to.

[Al Boondy]

Originally Posted by continentsco

My concern right now is that the C channel is bent in certain spots, nothing major, but enough that it is going to make sliding new wood in very tricky. Should I use a router bit on the edge of 3/4 marine grade plywood to take it down to 1/2 inch to make it easier to slide in?

I planed a short piece oak to slightly thicker than the plywood then chamfered the edges and used it return channel to original size. Couple of taps with a hammer.
A belt sander works great on the plywood to reduce the thickness and chamfer it's edges for easier insertion.

[Belegedhel]

Don't carve the edge of your plywood any thinner. Better to straighten up the C-channel. The channel is likely bent in the first place because it is not getting any support from the rotting wood that is supposed to be under/in it. If you can get away with doing a shell-on floor replacement in the front and back, leaving the central areas with their cabinetry alone, this may be best case scenario at this point.

Also, marine grade plywood is not necessary. The benefits of marine grade are a higher number of layers and less voids. It will still rot when wet. Just use a decent grade plywood so that you don't have to waste a bunch of time smoothing it out before laying your flooring. Coat it (especially the edges) with a few layers of poly, and you will be way better off than the trailer was built at the factory. Why they don't just use papier mache instead of that OSB, one has to wonder.

good luck!

[continentsco]

Originally Posted by Belegedhel

Don't carve the edge of your plywood any thinner. Better to straighten up the C-channel. The channel is likely bent in the first place because it is not getting any support from the rotting wood that is supposed to be under/in it. If you can get away with doing a shell-on floor replacement in the front and back, leaving the central areas with their cabinetry alone, this may be best case scenario at this point.

Also, marine grade plywood is not necessary. The benefits of marine grade are a higher number of layers and less voids. It will still rot when wet. Just use a decent grade plywood so that you don't have to waste a bunch of time smoothing it out before laying your flooring. Coat it (especially the edges) with a few layers of poly, and you will be way better off than the trailer was built at the factory. Why they don't just use papier mache instead of that OSB, one has to wonder.

good luck!

Next question. And getting ahead of myself. If the interior width, i.e, from the interior side of the exterior wall to the other interior of exterior wall (if that makes sense) is 8 ft, but the width between C channels (road side to curb side) is only 7 3/4ft, how do i get a 8ft wide piece of plywood into that gap? I know I could do 4 and 4, but ideally id like one piece of 8x4 to go the entire width of the trailer so the entire front section of shell is connected to the same piece of wood.

Lets see what you got now.

[Belegedhel]

Do a google search for "shell on floor replacement." There are a few threads, and they all describe how they dealt with the problem that you are speaking of.

Short answer is that if you were to completely disconnect the shell from the frame and the belly pan, you might be able to stretch the shell "open" enough to give you the clearance you need to get the full width sheet into place. Since you probably are going to leave the center section of the trailer alone, it is unlikely that you will be able to do that.

With this in mind, you will very likely have to split the flooring into two halves, get them into place and then join them in the middle with a doubler underneath.

good luck!

[HiHoAgRV]

I replaced sections with a scarf in the center

http://www.airforums.com/forums/f36/...tml#post733344

[HiJoeSilver]

Well the good news is you're well on your way to a full monte, bad news is you're well on your way to a full monte.

Lots of good suggestions from others so far.

Sides are usually wrapped inside the c channel. The ends have U channel sitting on top of the plywood. Treat the edges of the plywood with epoxy or polyurethane to seal them. I also wrapped my edges in several layers of heavy aluminum foil tape for more barrier.
Rear is worst for rot. Shell off is a good time to add some flashing to prevent future damage.

"Short answer is that if you were to completely disconnect the shell from the frame and the belly pan, you might be able to stretch the shell "open" enough to give you the clearance you need to get the full width sheet into place" could result in she'll slipping over edges and down to the ground around the frame. If you're at the point of shell disconnected and belly pan removed you'd be better off lifting the shell to replace the floor.

[cliffcharb]

I would place the seams over the frame rail. That would give you a nice solid joint. I wouldn't want the seams in the middle of the trailer as that's the most used portion and it would tend to feel soft from the flex.

[HiJoeSilver]

A good wide strip of 3/4" plywood doubler and a good amount of liquid nails would be very solid.

[perryg114]

It is important that the floors goes under the walls. It is not that important that it is a continuous piece. What I tried to do on mine is weld some angle onto the cross member where the seam was so that each piece of plywood had a place to attach to the frame. The major structural connections to the frame are at the front and back. This is what stiffens the shell and frame. Actually, the frame is supported by the shell. As you go around the corners there are wood screws holding the floor to the c-channel. There are 1/4 bolts where the outriggers meet the c-channel and the floor is sandwiched between the two. You really need to remove the lower skins to have proper access to these front and rear structural connections. There you will find rotten wood, wet fiberglass, and rusted steel as well as all manner of funk.

Perry