Sub-Floor with Belly Pan and Shell On

[Llano]

First, after months of lurking on Airstream Forums I must compliment all who make this tremendous resource possible. I'm brand new to the Airstream world and am amazed by the abundance of well-organized information. Props up!

Just rescued a 1966 Overlander from a goat field. Circumstances demand that I install a new sub-floor without removing the belly pan and with the shell on. What's the best strategy for securing the plywood? Pre-drilled holes with self-tapping metal screws?

[Wabbiteer]

I've got to withhold comment about the flooring - but I will say you have a once in a lifetime chance to pressure-wash the interior spaces now...

[RoverOwner]

Shell on is possible, but I think you need to take the belly pan off. There are bolts holding the floor / c-channel / frame together at the outriggers. Also, the elevator bolts that hold the floor to the frame through the cross members add a lot of strength. I wouldn't want to have just screws holding my trailer together.

You're so far along, it's just a matter of drilling out the rivets that hold the belly pan to the sides and frame. It's not that hard, and in the end you'll have access to the entire frame to paint it and make it better than new. Don't scrimp now.

Besides, restoring these things is fun. Don't cheat yourself.

[pbearsailor]

Read Shari's great thread http://www.airforums.com/forums/f91/...irl-31084.html. They did the subfloor with shell and bellypan on.

cheers,
steve

[Llano]

Pressure wash done. Took it to a do-it-yourself car wash so the pure unadulterated nastiness could be captured by their system. Who knew that insulation turns to mud after it's exposed to the elements for 20 years?

Mouse Nest Hunter? In that case you KNOW of what I speak! Mice would have been nice, it's the other furries that left the most behind. My conscience and heart know you are right about the need to remove the belly pan but my competence and available time are limited. On my next AS adventure I will do a better job of sequencing the work - promise!

[InsideOut]

Originally Posted by pbearsailor

Read Shari's great thread http://www.airforums.com/forums/f91/...irl-31084.html. They did the subfloor with shell and bellypan on.

cheers,
steve

Thanks Steve!

Yes we did replace the floor with the shell in place. In many ways it would have been easier to take it off, but we couldn't due to space constraints and several other reasons. The way the 50's trailers are secured around the perimeter, we would have to take the shell off even to fully drop the belly pan, there are hidden rivets under the shell that hold the one piece belly in place. I know the floor channel in the 60's trailers are different than ours - but a similar technique may exist. Another thought we had was to cut a rectangular section of the belly pan out just under the outriggers inside of the banana wraps to access the underside of the frame - then replace the belly with a larger sheet that overlapped the cut. But we didn't go that direction.

We used a combination of elevator bolts & self-tapping screws, both available at VTS. The bolts were we could access the frame members and the screws where we couldn't. We added more than original and know it is every bit as strong as before - if not more so. The main section of posts that relate to this are #165-200.

If you have any questions, I'll try to answer them as best as I can.

Shari

[Llano]

Super helpful. Many thanks to all. I look forward to posting on our progress!

[Llano]

Is marine plywood appreciably better as a sub-floor to justify the additional expense? I know there are fume issues associated with pressure treated plywood but have the chance to potentially use some big box store gift cards to buy my sub-floor and unfortunately the big guys/gals don't sell marine plywood. Is there a way to mitigate the release of those fumes?

[bwaysteve]

Originally Posted by Llano

First, after months of lurking on Airstream Forums I must compliment all who make this tremendous resource possible. I'm brand new to the Airstream world and am amazed by the abundance of well-organized information. Props up!

Just rescued a 1966 Overlander from a goat field. Circumstances demand that I install a new sub-floor without removing the belly pan and with the shell on. What's the best strategy for securing the plywood? Pre-drilled holes with self-tapping metal screws?

Llano,Check my thread "gutting the 65" Mine is an Ambassador,but same setup as the Overlander.Drill out those bellypan rivets around the perimeter and in the center.When you take out the bp it leaves the banana wraps attached to the skin but hanging down like a skirt.When this is exposed cleanup the frame and treat with POR rust proofing. With the bp off you can get the whole frame.I just used the gray paint with no top coat as it won't be exposed to UV light once the bp is back on.
I am putting gray and black tanks in this week then will go for the floor.
IMO A/C ply is sufficient if you treat the edges with epoxy.(remember an untreated floor lasted 45 yrs.)
Take it all apart since you have gone this far.Do it right.It is not hard .Steve

[MarkR]

Hi, this is just my opinion . . .
I don't think it necessary to use marine plywood but I also wouldn't buy the plywood that the big box stores sell. I go to a contractor's supply / lumber yard and buy their cdx plywood and I treat/coat/paint the edges (the cdx I can get at the blue and gray, starts w/ an L, big box store is cr*p).
MarkR

[GetOutDoors]

If you are going to use wood for your sub-floor, then yes, marine grade ply, with marine epoxy applied around the edges is hard to beat.

You should have found, while taking the old floor out, that Airstream bent the bolts over after they tightened the nut so the bolts would not come loose. The bolts that went through the c-cannel through the out-riggers are of special importance. They are also the most difficult to deal with if the belly pan is not remove.

Flanged elevator bolts seem to work best.

BTW, make sure you use corrigated fasteners on the seams every 4 -5 inches to keep the edges of the seperate sheets from movement as the TT goes down the road, especially if you plan to use glue-down flooring.

There are many threads here in the forum that are very enlightening ...

[bwaysteve]

Originally Posted by Spiffy Gem

If you are going to use wood for your sub-floor, then yes, marine grade ply, with marine epoxy applied around the edges is hard to beat.

You should have found, while taking the old floor out, that Airstream bent the bolts over after they tightened the nut so the bolts would not come loose. The bolts that went through the c-cannel through the out-riggers are of special importance. They are also the most difficult to deal with if the belly pan is not remove.

Flanged elevator bolts seem to work best.

BTW, make sure you use corrigated fasteners on the seams every 4 -5 inches to keep the edges of the seperate sheets from movement as the TT goes down the road, especially if you plan to use glue-down flooring.

There are many threads here in the forum that are very enlightening ...

Just a follow up for Spiffy's seam fastening comment.Since yours is a 65 you should have pulled out with the floor, strips of plywood maybe 8in.wide that drop into and bolted to recessed portion of the frame under the seams.Use screws along the either side of the seam line to attach the floor to this strip.
When you drop these sections in, the whole frame surface becomes level for floor installation.

[GetOutDoors]

I forgot that: thanks bwaysteve.

I might add that 5/8ths is the thickness used in 66. If you use 3/4, like I did, you will find some of the subfloor exposed in the back - between the two main frame beams - where the distance between the c-channel that binds the shell to the floor, and the bottom of the shell is too shallow to span the thicker ply. There will also be a gap to seal between the door jam and the step hardware.

[Llano]

Brought the Overlander home from the body guy last night. Let the interior begin. I can polish when it's not 104 degrees outside.

[Llano]

Sub-floor cut to size, sealed four times over on both sides and is ready to be screwed into place. Amazing what you can still accomplish when the heat index tops out at 110...

[Llano]

And on a related matter, any suggestions on covering those wheel wells? Am considering building two light "boxes" to cover/protect each and to be hidden under the yet-to-be build kitchen and seating.

[Bauxter]

Did you end up using the marine grade, or the CDX?

[utee94]

Originally Posted by Llano

And on a related matter, any suggestions on covering those wheel wells? Am considering building two light "boxes" to cover/protect each and to be hidden under the yet-to-be build kitchen and seating.

Just wondering, is there a reason you want to cover them? Is it aesthetic, or do you have something else in mind?

If you're going to build out the interior with furniture that is identical or close to the original configuration, then the wheel wells will be entirely hidden within the furniture anyway. If you have another interior plan in mind, one that exposes the wells, then I suppose covering them with something could be a good idea.

I just painted mine with rubberized underbody coating. They are hidden under the beds and cabinets anyway.

The subfloor looks great, please do keep us posted on your progress.

-Marcus

[Llano]

Alas the budget did not allow for the marine. Maybe I should have sealed each side EIGHT times!

[SilverHoot]

One reason that comes to mind for covering the wheel wells is that it allows an area between the inner and out to install insulation.