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polarlyse · 03-31-2011, 03:39 PM

I been trying to do my homework by reading here on the forum. I'm about to tackle some flooring work. We've been on the road for the past month traveling throughout Florida and just got home the other day. During this trip we found we had a significant water leak. It seems to come from the curb side front window. The one by the door that does not open. I found that the outer seal between the glass and frame had some gaps and I think that was allowing the water in. I've sealed them and now we'll see if the leaks are taken care of. If not, I'll be back to tracking them down. With the leak stopped ( hopefully ) I plan to soon begin to replace some of the flooring in the front section. So far, from the flooring I've pulled up I've found a combination of flakeboard and plywood. I suspect the flakeboard was original from manufacture and the plywood in the front section was a replacement. The bad subfloor begins in front of the door and extends forward to the sofa. That's as far as I've pulled up. I suspect it goes farther. It looks to be about 3' in towards the centerline. Once I remove the sofa and pull up some more flooring I'll have a better idea as to the extent of subfloor that will need to come up.

From what I've been reading I gather that I will need to remove or at least lower some of the belly pan to get to the bolts and remove them. Then begin by removing all of the bad wood that I can. I haven't removed any of the inner wall yet but will take the lower section out to gain access to the bolts and "C" channel that I read about. I expect to find a mess below the floor. Wet insulation and whatever else may accumulate there or find it's way in. I was wondering about the subfloor material. I built a shed a few years ago and found a pressure treated plywood and used it with very satisfactory results. I see postings about plywood, marine plywood as well as some non-wood sheet materials. Nobody seems to be using the pressure treated stuff. Is there a reason why ???? I'm wondering if there is a problem using it in a living space. Of course I won't use it if that is an issue. Then marine plywood would be my selection in that case. I plan to begin as soon as the weather allows so this will be my spring project.

I have most of the tools for the job, what materials should I expect to have on hand at the onset ????? I'm trying to think ahead on this one.

Thanks, sorry for the long posting, these jobs require a lot of planning.

68 TWind · 03-31-2011, 04:05 PM

You pretty have the picture as to what is involved. A grinder with thin cutoff wheels works well for the bolts you can get too. Most will be rusted and when you try to unscrew them they whole thing will turn. For the tight spots a Dremel tool with cut off wheels make short work of the bolts. I cut off nearly all the bolts in the C-channel on mine because all were rusted and none would turn. Another very useful tool is one of the new vibrating saws, aka Multimaster type. Harbor Freight has them. It very useful in removing the old floor. Mark down the center of the rail or outrigger and then use the vibrating saw to cut down to the metal and then along it. You can't do that with a circular saw or recip saw. The kerf is very small and that is another good thing. I used that tool more than any other when I replace the floor in the rear of my Trade Wind. But the thin blade and and get several extra.

Bill M. · 03-31-2011, 04:09 PM

Opinions, but not necessarily facts. Treated plywood is a poor choice. It can interact with both the steel and the aluminum to cause corrosion. Should not be needed because the floor is supposed to be dry. You have to fix the leaks. Standard plywood is fine. Marine plywood would be fine, but is a totally unecessary extra expense and trouble to get. All southern pine plywood is glued with waterproof glue. The marine plywood has better inner layers without spaces for leakproof joints in a boat. But that is not needed on a floor.
I decided not to take the channel bolts out on my floor repairs. I notched the plywood so that it fit in the channel, but around the bolts. That procedure results in a floor that is just as well mounted as if it had the bolts through it, in my opinion. The plywood is fully in the groove of the channel, the channel is supported from collapsing, and the channel is fully bolted to the frame. Having a bolt go through the extreme edge of the plywood adds no strength at all. I used 3/4 inch plywood and cut a little off the edges from the bottom to make it go in the 5/8 inch channel. That is the way Airstream did my 88 with the OSB.
I had to put the plywood in in sections to get it recessed in the channel fully on both sides. Unlike some advice, I deliberatly made the joints not fall on a frame member. I glued and screwed a piece under the floor to make a lap joint. Much stronger than having a joint on a frame with only 3/4 " of support on each piece. I was able to get the treck bolts out of the floor and reuse them. You can buy them at Lowes if you need to.
If you do it the way I did you do not need to take off the belly pan, or the bananna wraps, or any of the interior aluminum skin. And it works fine.

wasagachris · 03-31-2011, 04:10 PM

Roger the chemicals it PT ply will react negatively with aluimnium and yes there is the off gassing to be concerned about in a living space.
You`ll need some elevator bolts and floor screws to fasten the new floor sheet to the frame. Vintage trailer supply sells them.
Screws & Bolts

Seal the new wood with some waterproofing.
You would also need some vulkem to seal any exterior seams that you open up.
Vulkem

Also some large head rivets to reattach the belly pan.
Large Flange Rivets

You also might want to rethink the insulation in the belly pan and not use fiberglass.
Insulation for Less : Prodex : Reflective Insulation : Pole Barn Insulation : Metal Building Insulation : Bubble Insulation

wasagachris · 03-31-2011, 04:20 PM

Quote:

Originally Posted by Bill M.

Opinions, but not necessarily facts. I decided not to take the channel bolts out on my floor repairs. I notched the plywood so that it fit in the channel, but around the bolts. That procedure results in a floor that is just as well mounted as if it had the bolts through it, in my opinion. The plywood is fully in the groove of the channel, the channel is supported from collapsing, and the channel is fully bolted to the frame. Having a bolt go through the extreme edge of the plywood adds no strength at all. I used 3/4 inch plywood and cut a little off the edges from the bottom to make it go in the 5/8 inch channel. That is the way Airstream did my 88 with the OSB.
I had to put the plywood in in sections to get it recessed in the channel fully on both sides. Unlike some advice, I deliberatly made the joints not fall on a frame member. I glued and screwed a piece under the floor to make a lap joint. Much stronger than having a joint on a frame with only 3/4 " of support on each piece. I was able to get the treck bolts out of the floor and reuse them. You can buy them at Lowes if you need to.
If you do it the way I did you do not need to take off the belly pan, or the bananna wraps, or any of the interior aluminum skin. And it works fine.

Bill you are right opinions but not fact. I have seen floor repairs done using your method and the trailer fell apart. I definately would not recommend that type of repair at all. Respectfully you have made a seroius error with this repair. Of course this is my opinion as well. Many others including professional restorers will agree with me. No offense meant so please don`t get angry with me.

COACHJEFF · 03-31-2011, 06:49 PM

I did not remove belly pans, i had to remove all floor finish this exsposed elevator bolts, I took pilot bit out of a (1")hole saw to drill around elevator bolts down to frame. Then cut chanel screws and bolts with grinder. You can use a skill saw to cut down thru plywood, set debth just light of plywood thikness. Use multimaster for short finish cuts. It is a great tool but slow on long cuts and blads are costly. If you can get one middle section of plywood out others will get easier. FYI once plywood is removed around door and wheel wells install temp spacers into chanel for protection of outside skin at these weaker spots.

polarlyse · 03-31-2011, 08:03 PM

I guess that I knew all along that pressure treated plywood would not be appropriate for this job. Thanks for telling me why. I guess there's usually a reason that the easy way just seems wrong. A lot of the subfloor is very, very spongy. I expect it to be messy but not difficult to remove. At the cuts though I will take the xtra to keep them nice and straight and square. I expect to find the usual rust below too. If I need to replace and weld new metal in that will be the easy part of the job. I think I'll go the POR 15 route if needed too. I like the idea of putting some scraps into the "C" channel to keep it from deforming. Thanks for that one. It seems most people use 3/4" plywood and reduce it at the edges to fit the channel. Is there a reason to not simply use 5/8" from the onset ?????? Could it be that the 5/8" ply is simply not strong enough for the floors ????? Just thinking out loud.

Thanks all for the input. Just waiting for the weather here.

Bill M. · 04-01-2011, 08:04 AM

"I have seen floor repairs done using your method and the trailer fell apart."

You have never seen a trailer I repaired. And my 2 have not fallen apart. There is absolutely no strength added by having the elevator bolt go through the edge of the plywood within 1/2 inch of the edge of the panel. As long as the plywood is securely up into the channel it is fine. Now if someone goes in and removes the elevator bolts and then does not replace because they could not get to them from the bottom them you got a big problem

ventport · 04-01-2011, 08:24 AM

Quote:

Originally Posted by Bill M.

"I have seen floor repairs done using your method and the trailer fell apart."

You have never seen a trailer I repaired. And my 2 have not fallen apart. There is absolutely no strength added by having the elevator bolt go through the edge of the plywood within 1/2 inch of the edge of the panel. As long as the plywood is securely up into the channel it is fine. Now if someone goes in and removes the elevator bolts and then does not replace because they could not get to them from the bottom them you got a big problem

I think the reason to remove the belly pan when replacing the floor is so you CAN REPLACE the rusted elevator bolts. If the floor is rotten the elevator bolts will most certainly be badly rusted. The elevator bolts hold the body to the frame. Not hard to figure out what happens if enough of them break due to rust. You could have the best looking floor around, with your aluminum body laying in the ditch if you don't replace the elevator bolts when doing a floor replacement.

Bill M. · 04-01-2011, 09:16 AM

Good point. I did not think my elevator bolts were rusted enough to fail, but I could be wrong. Yeah, the best thing to do would be to take them out and replace. Whether they actually go through the plywood or not is a small point. But if they break, that is indeed a big problem.