Rotted floor

[Bigjohn59]

So I'm sure it's on here somewhere but I wondered I anyone had any tips on changing the plywood in the rear bedroom in a 78 31 foot sovereign, most of what I read involved removing the shell but I don't really want to do that, any tips would be greatly appreciated

[Stoney]

You should b able to take everything out of the room. Take a skill saw get it close as u can to the wall set it at 3/4 inch plywood cut it then remove .I have done it before but not no a airstream .Good luck post if it works. Stoney

[wahoonc]

Search for rear bath floor replacement, it is very similar. It can be done without completely removing the shell. I am in the process of doing something similar on my 1975. The hard part is getting the old plywood scraps out from under the edge channel extrusion, lots of quality time with a chisel and hammer.

Going back in I split the sheet down the middle with a 45* saw cut slid one side in, then the other, used gorilla glue and screws to secure the joint.

Aaron

[wasagachris]

Originally Posted by Stoney

You should b able to take everything out of the room. Take a skill saw get it close as u can to the wall set it at 3/4 inch plywood cut it then remove .I have done it before but not no a airstream .Good luck post if it works. Stoney

Absolutely the wrong way to replace a floor in an A/S.
The floor is the main structural component attaching the shell to the frame on an airstream. It provides the rigidity to properly hold the shell to the frame and if you cut the floor like this you will seriously comprimise the strength of your trailer.
There are bolts inside the wall attaching the shell through the floor into the outriggers of the frame. The inner skins must be removed to access these bolts. You must also remove the belly pan(aluminium bottom) of the trailer to access the bottom of the bolts to tighten the new ones upon installation of your new floor.
First let's start with a little terminology. The body oy the trailer is called the shell. The interior walls are commonly refered to as the inner skins.
The walls in between rooms are called bulkhead walls. The aluminium covering the underside of the trailer is called the belly pan. Along the outside of the trailer at the lower edge of the shell there is a piece of aluminium that curves under the shell to transition from sides to the belly. I call them side wraps. On each corner of the trailer again at the bottom of the shell is a curved piece shaped somewhat like a banana, hence they are called the banana wraps. At the point where the shell and side wraps meet is a trim molding it is called the lower beltline trim. Inside the walls an extruded aluminium channel is used to attach the outer skins and inner skins to the shell. This C channel is also used to attach the completed shell to the floor and frame. There are two designs of this C channel. The curved ends of the trailer(end caps) use a single C channel and along the straight sides of the trailer use a double C channel. The single C used on the end cap area is vertical with the legs of the C pointed upwards and just sits on top of the floor. The double C channel is both vertical and horizontal, IE: the vertical part is the same as the end caps and the horizontal part forms a track for the floor to sit in.
I know that is a lot to take in but you can refer to this later and it will make discussion between members easier.
Moving on to your question. Replacing the last section of your floor is relatively easy compared to the rest of the floor due to the single C channel.
First remove all the furniture in the bedroom (2 single beds and the night table between them. they are just screwed down to the floor with wood screws.
Next using a drill with a #30 or 1/8" drill bit drill out all the rivets attaching the lower pieces of the inner skins. you should be able to roll the side parts forward into a coil still attached to the rest of the shell to expose only the area you are working on.
Remove all the insulation to see inside the walls. Now you will be able to see the C channel and the bolts.
Next go outside and using the same drill, drill out the rivets attaching the lower beltline to the shell. this beltline is in pieces remove enough to get at the area for repair. This will now expose the rivets attaching the side wraps and banana wraps,again drill them out.
Now go underneath the trailer and using a larger 3/16" drill bit drill out the rivets holding the belly pan to the frame. Once the belly pan is dropped far enough forward in your work area you can remove the insulation. you will find some very nasty surprises under there.
You are now ready to remove you rotten section of floor. There are several floor screws attaching the floor to the frame and as I mentioned earlier bolts called elevator bolts inside the wals attaching the C channel through the floor into the outriggers. Remove all these bolts and screws. There are also several small wood screws used to attach the C channel to the floor these need to be removed as well.
Last but not least at the rear of the trailer are two larger main hold down bolts and a steel plate calle dthe rear hold down plate. Before removing them support the frame from below with some jack stands. the frame is surprisingly flexible and will drop down quite a bit once you remove these bolts(ask me how I know).
That will get you started and I can go on later as how to replace the floor and the installation process.
I suggest you get all the materials you need first before doing any tear down.
Elevator bolts and floor screws can be purchased from fastenal and another place from which you can purchase them is Vintage Trailer Supply. They have exactly what you need and make it easy to source the correct ones. Vintage Trailer Supply - parts and supplies for vintage travel trailers and campers!

[Bigjohn59]

Excellent, thanks I'll try and get started this weekend maybe next

[Skatiero]

Really nice explanation, wasagachris!

[perryg114]

I just did what you are about to do. Be thankful you don't have a rear bath model. Take your time and ask lots of questions.

Perry

[Bigjohn59]

I'll definitely take my time, and I have a 66 international rear bath that I currently live in, and iv bin afraid to look at the floor because I have a feeling it's bad, partof the reason I picked up the 78 sovereign last weekend lol

[Bigjohn59]

So iv removed my front carpet and center linoleum and discovered some rot in the right front corner of my 78 sovereign as well, iv now come to the conclusion I hate carpet for the water holding feature it has, is the front section similar to changing the rear? What is a trailer in pretty decent shape like this worth, before I discovered the floor? And anyone have any thoughts on where the most probable source of my water?

[Bigjohn59]

Anyone know how to post pics from an iPhone?

[perryg114]

There is a gap in the C-channel in the corners. Any water will run down the C-channel and into the floor at that point.

Perry

Originally Posted by Bigjohn59

So iv removed my front carpet and center linoleum and discovered some rot in the right front corner of my 78 sovereign as well, iv now come to the conclusion I hate carpet for the water holding feature it has, is the front section similar to changing the rear? What is a trailer in pretty decent shape like this worth, before I discovered the floor? And anyone have any thoughts on where the most probable source of my water?

[wasagachris]

Originally Posted by Bigjohn59

So iv removed my front carpet and center linoleum and discovered some rot in the right front corner of my 78 sovereign as well, iv now come to the conclusion I hate carpet for the water holding feature it has, is the front section similar to changing the rear? What is a trailer in pretty decent shape like this worth, before I discovered the floor? And anyone have any thoughts on where the most probable source of my water?

Good Morning BJ yes the front section is assembled exactly the same as the rear. It is a single C Channel around the end cap sitting on top of the floor and again bolted down inside the walls into the outriggers. There is also a front holddown plate bolted down with larger bolts into the main frame rails. Floor screws are used on the interior section of the floor to the crossmembers of the frame.
Value is such a relative thing. Location is a large factor for us Canucks. W e usually pay more for these trailers due to the lesser number of units available. Decent condition is also very subjective. IMO $4k to $6K for a fully functional original condition unit is the range. Timing is also a factor. The prices have begun to rise now as the camping season approaches and will drop into thefall and hit the low point over the winter.
leaks in the front, most likely are the wing windows, if your unit has a rockguard over the front windows then the attachment points for that rockguard would be a suspect point. The letters AIRSTREAM and the front clearance lights need inspection too. IIRC the 78 sov has two front battery compartments, they are also a common leak point both from outside penetration of water and battery acid from boiled over or failed batteries.
A little bit farther back on the coach are the Vista View and stack windows. The VV's over top of the lift up windows are a huge point of entry for water. Much has been discussed on repairing, replacing and even removal and deletion of these windows. Stack windows are the fixed units below the lift up windows in the living area. Do a google search and you will find numerous threads dealing with these windows.

[deelind]

Helpful advice! I'm replacing front and rear. I read somewhere that the edges of the new plywood should be sanding a bit for an easier install, did I hear that right?

[Bigjohn59]

So this is my rear right side, looks like a double panel wrapped right down to the frame rail, anyone know what the idea of that might be?

[Bigjohn59]

And this is my left side, was a separate piece on the bottom I managed to get out on it's own

[perryg114]

It does not look that bad. You might get by with removing just the rotten section on that one and treat with bleach to kill the fungus on the remaining area. It is kinda hard to tell what the overall damage is from the photos but what I can see is no that bad. The area where it connects to the rear of the shell is the most critical structural area.


Perry

[trailer-tras]

the shell is connected to the plywood subfloor on the outter edges or perimeter of the wood floor which is attached to the frame. it is quite a job and requires jack stands to do it correctly. the only way to replace the subfloor correctly is to do a partial frame off of the back end of the trailer.
in my case i am going back in with all new rear steel framing, walls bathroom etc...
you can do this without removing the walls and lighting as i did and make sure to use the old floor as a template of course for those tricky arches. the important thing is to find the source of your leaks which damaged the floor. the #1 culprit is the back end of the trailer where the subfloor meets the outter shell, i will be installing an aluminum roof flashing that goes between the wood and the outer shell, again i will send pics once thisis done. #2 check your plumbing vent as this may have a bad seal at the roof and water trickles down the the floor when it rains.
#3 the wheel well may splash water up underneath the trailer thus wetting the subfloor so make sure the wheel well area is seal correctly also.
i will send more pics as i continue with my restoration. i will be putting my floor back in this coming weekend. good luck with yours

[Bigjohn59]

I noticed the belly pan in the center stretches right back to under the bumper compartment, should it be sealed off, there was no sealant, and I don't think the bumper compartment is water tight, thus allowing water into the belly pan rotting the floor from the bottom? The bottom of the wood is definatly worse than the top

[wasagachris]

Originally Posted by Bigjohn59

I noticed the belly pan in the center stretches right back to under the bumper compartment, should it be sealed off, there was no sealant, and I don't think the bumper compartment is water tight, thus allowing water into the belly pan rotting the floor from the bottom? The bottom of the wood is definatly worse than the top

John yes the belly should be sealed to the last crossmember. It was originally but probably has long since disappeared. I would also drill some drain holes in the belly inside that storage area to allow the water to escape. You are seeing excatly what the water does once it gets into the belly, rotting the floor from below and rusting out the frame. Use a good rustproofing paint like POR-15 on the frame, seal the plywood with a water proofing material and use a different material for the insulation. The fiberglass only acts as a wick and storage membrane for any water that can get into the belly.

[Bigjohn59]

That's what I was thinking, thanks, anyone ever use spray foam on the floor? Iv seen it on the bottom of tractor trailer cabs exposed to the elements and it seems to work good there