What is the lifetime of a wooden floor and how to replace it?

[Hans]

I have just bought a 1979 Safari and are changing the interieur. As I pulled out the original carpet I realized, that the floor consists of wood. I wonder, when it is time to replace such a wooden floor? And is it possible to change the floor from the inside?
Your advice is really appreciated by Hans

[Pahaska]

Replacing the floor is major surgery. If the floor is still in acceptable condition, I would leave it alone. If there are soft spots at the door or in the bathroom, I would replace those sections only.

The floor is fitted into the channel that runs around the trailer. To replace the entire floor means pretty much disassembling the trailer. There have been some threads and some great photos on this forum from a fellow who did just that. It was a major project.

[j54mark]

Absent a leak that has caused extensive rot, or termites, or some similar disaster, the floor should last the life of the trailer. Whatever that may be.

Mark

[hex]

John I think understates the seriousness of the surgery to replace a floor. He says major surgery, I say catastrophically-major major surgery! This and total frame replacement would IMHO be the most serious undertakings. Maybe total skin replacement would be tougher, but I'm only imagining.

Also if I am correct the floor is attached to the frame and the shell perimiter-channel is attached to the top of the plywood. I was not aware that the plywood edge was inserted into a channel as well. The narrow perimiter edge of the plywood upon which the shell/channel rests is the key. Unless it was rotted to such a degree that the shell had dropped for great lengths (and even then it could likely be lifted and re-filled with new (treated) "sill" pieces). Any rot or soft spots inside the perimiter can be removed and new sections,plugs,patches,etc. be fit and filled in. That is not to say that those will all be easy.

Today there are epoxys that can be applied and injected into rotten wood to stop the process and restore where removal is not practical.
See www.rotdoctor.com

I doubt the flooring in vintage Airstreams was treated, although I know that treated plywood was available back in the 70's if not earlier. I have also wondered if the flooring is T&G (tounge and grooved) plywood. Not sure that would have been wise however due to the need for a little flexibility during travel.
I have read somewhere on one of the forums or disc. groups that it was marine grade plywood, I have my doubts, but that would be nice too.

[74Argosy24MH]

Just remember when patching all edges must sit on floor supports or you will have a soft area.

The trailer body lower channels that I have seen sit flat on the floor. The motorhome lower channel wrap around the floor.

To do a total floor replacement you have to pull the body. I would rather replace skins. The floor in my mh was 1/2", I doubt if it was marine, know it wasn't treated (treated would not be real great as it would out gas some pretty nasty stuff and it is indoors), it was not tongue and groove, you are probably right about flex and the tongue or groove splitting out from the movement. Some used OSB instead of plywood.


John

[Pahaska]

The floor is made from 5/8” tongue and groove plywood. The aluminum channel is fastened to the floor and to the shell assembly. Notice the bottom slot in the channel. This embraces and protects the edge of the wood floor, giving the joining of the floor to the shell strength and weatherproofing.

The above obviously applies to current builds. I have no idea how far it goes back in time. But yes, at least currently, the edge of the floor is in a slot in the channel and the floor is tongue and groove.

[Pahaska]

The dealer told me that the current floors, at least, are marine plywood. That would imply waterproof glues and upgraded interior plys.

[BobbyW]

Hans;

Floors in the 60's and 70's models are untreated, exterior grade tongue and groove 5/8" plywood. The tongue and groove was/is glued and stapled from the under side. It has a bazillion staples. It is not going to come apart. In the center wear areas it has an underlayment of 3/8" in for additional support.

Treated plywood is poisonous and a carcinogen. CCA = Copper, chromium, arsenic.

Floor replacement is MAJOR work. I am still working on mine. Unless you have a good covered shop to work on it, it is just not worth the effort. The shop allows you to remove the entire shell from the support frame and replace the whole floor at one time which is the right way to do it.

If you can push an ice pick through the perimeter edges, you have problems. The perimeter is what holds the Airstream together.

You can replace the floor without removing the shell but it will take a lot longer to do the job. I know. Mine started out with just replacing the flooring under the rear bath, which was gone around the entire rear perimeter. This much is completed. As I progressed I decided to replace the front also. I have the frame painted and the pieces cut, ready to go back in with it.

As far as using a water seal, I talked extensively with the engineers at Thompson's. They advised that their product is for exterior use only and not to be used in an enclosed environment.

Marine rot repair products work very well and are a tried and true process for repairing small area's and preventing further damage on wood that is questionable. They are not structurally strong enough to support the shell though.

As far as how long will a plywood floor last...I would say 30-40 years. The center of my floor was as good as it was when it was installed. Very solid. I read your other post about leaks and this is the real destroyer of floors. Everywhere you mentioned as leaking is cause for concern.

If the previous owners of mine would have just fixed the leaks when they occurred, mine would have been solid to this day.

Good Luck and keep us informed on your discoveries.
-BobbyWright

[74Argosy24MH]

From another forum:

Yep John, It is not plywood anymore. My 76 was plywood, but my 85 is
chipboard. I don't know when they started doing this. For the price
you pay for an Airstream, I think this is a shame, but at least they didn't use
particle board.

[j54mark]

"It is not plywood anymore... I think this is a shame,"

I have to acknowledge up front that I am not really an expert, but having used both chipboard and plywood in a number of construction projects, I am not sure that chipboard was an inferior product in this application, at least as compared to ordinary plywood, or even exterior grade plywood. I am not wedded to this idea, you understand, but chipboard is wonderfully stable, is not subject to delamination, and really makes a very nice floorsubstrate.

I think I had also read or heard that they now use marine plywood, which is a really superior product. It has no voids, and the glues are very water resistant.

Mark

[Bubbla]

Hallo Hans,
erst nehme dünnen schraubenzieher und steche endlang der wände, um zu festelen ob du weiche stelen findest. Das holz was die benutzen ist absolutes schrot. Mein floor hat keine fünf jahre überlebt. (neues motorhome)
Auch wenn du keine weiche stellen findes, empfiehlt sich
denn boden mit guten dünflüsigen epoxy zu versiegeln, um diese probleme zu verhindern. Fals du fragen zum details hast, bin ich gerne bereit dir zu helfen.
Grüss
alex

[NewStreamer]

Ron

[BobbyW]

I think it translates....

Hello Hans,

Take a thin screwdriver and run it around the perimeter and look for soft parts.

My floor did not last 5 years (new motorhome).

Even if you find soft spots, it is not recommended to treat with a epoxy seal, in order to prevent these problems.

If you need details, I am gladly ready to help.

Regards
alex

...At least that is what my American-German wife says.

-BobbyW

[NewStreamer]

Thanks, Bobby

[Hans]

@ Bobby, your wife does really good in translation. Just the last sentence goes different. The translation of what Bubbla said means "Even if you DON´T find soft spots, it is recommended to treat the floor with epoxy seal"

@ Alex: Thanks a lot for your advice! The floor just has one soft spot of about 10 x 10 cm, which is at the edge. I already have sticked the screwdriver in it and made a "hole" there. The rest of the floor is in rather good condition except for a few places, which are wet (the trailer has been 10 hours in heavy rain during the drive from Germany to my home. I plan to cut the part with the hole and replace it by a new part. I am aware that it has to sit on the edges.

Hans

[BobbyW]

Hans;

Do you have termites over there?

Damp floor spots are breeding grounds for them here. Kind of like a miniture Spa. I found them in mine and so have others.

-BobbyWright

[Hans]

Bobby, no, we do not have termites in Austria. Fortunately we do not have any insects, that like wood, except the "Borkenkaefer" (= bark beetle), which only likes the forest ... But maybe it could be, that termites have been imported together with the trailer but temperatures of below 0 degrees celsius and snow should not be a nice environment for them (I hope). Actually I never have seen termites before.
Currently I have a heater inside the trailer and am drying the floor.
I already have some ideas, where the damp could have come in, like in the rear, where the water heater is situated, it seems to be not completey sealed so moistness can come in from the outside, which probably was the case when I brought the trailer from Germany to Austria, beeing 10 hours on the road in continuously heavy rain.
The dealer told me, that the water heater itself is pretty new. Maybe the previous owner has not replaced the old sealing when having changed the heater, I suppose. So I will seal that whole thing.

Hans

[Bubbla]

Hallo Hans,
First sorry to all you guys about me writyng in German, but I thought let's give them something to do Sorry about that, maybe not realy polite.
Hans, if the spot is only 10X10 cm don't cut it out!! Seal it with Dr.Rot epoxy or simular. Take the carpet out, and dry the spot with some kind of heater. Drill few 5 mm holes about 15 mm deep and soke it. When done, seal the whole floor. In our climat it is realy important to do this, or you will replace the whole thing sunner then you thing. As I said before, my floor lasted only five years by brand new MH.

MfG
alex

[Hans]

Thanks everybody for the great advice, but the more I inspected the trailer, the more troubles became obvious. The floor was much more destroyed than it looked like at the first inspection. And then other problems arised, so I gave up and the trailer was driven back to the German dealer. He kept some amount of the money I paid, of course, but it still was worth it to give the Safari back, since I would have had too much money to invest.
But: We found a 1992 Sovereign, an original Europe edition of Airstream, in an incredibly good condition in Germany. We bought this trailer from a private person, and everything is just great, the floor, the interieur, and everything. Under bad wheather conditions (minus 16 degrees celsius) we brought the trailer to our home. So here is my new silver baby ...

[Chas]

Hans,

Congratulations!! Interesting wheels you got on it.

(Oops, hope InlandAndy doesn't get a look at them!)

Chas