Sagging Aluminum floors

[joe77]

Hi all
I have a 77 Argosy with aluminum floors. I'm in the process of remodel and i have plans of installing cork flooring. I have an issue with the aluminum floor sagging in between the floor supports. The floor is supported by cross ribs at 48" apart from each other (hence the sag). My first thought was to lay down 5/8" CDX on top of the aluminum floor, but Wont the 5/8" CDX sag with supports being 48" apart? I'm afraid any subfloor i install will overtime sag with the supports being 48" apart. Is this a valid concern? should i just install the subfloor as is and hope the sag wont return? Or should i rip the current aluminum floor out and install wooden joists in between the floor cross ribs (the ones that are 48" apart from each other). The latter will require a large overhaul of the flooring where as the prior will be an easy install. The differences in installation methods in respect to time/money are substantially different and I am limited with funds and time. What are your thoughts.
Thanks
~Joe

[vinstream]

I think that maybe installing more of the same type of supports that are all ready there may fix your problem. I have found that Airstream put less than more in areas of structure. Yes, it does make for a over all lighter trailer, which is key, but when I run into situations like these I tend to over build a little! You may be best to put supports every 12" on center using the ones already in pace! Just a thought!

Best of luck! Pictures may help in giving you more info!

[joe77]

Hi vinstream, Yes installing more supports will be ideal but that would require me removing the aluminum styrofoam sandwich floor already in place. This is a major overhaul and has so many implications. I'm afraid that if will open a whole new can of worms.
I've heard that the aluminum sandwich floor is not common. I'd love to hear from someone who has aluminum floors too.

[cameront120]

My first question is why is the sag a problem? Is it sagging to the point of being a danger? Is it just functioning the way it always has as per original specs? What will stiffening it achieve, besides being less 'saggy'? Are you worried that the new floor won't work on a floor with sag?

Floor movement will be a problem in any trailer, so I'd recommend putting down a floating floor. The floor won't be as prone to cracking if it is laid loosely on the floor.

[mutcth]

I have the same trailer you do, also with the aluminium floors. They were a major selling point for me, since I had no interest in dealing with or worrying about floor rot. Our floors are pretty even, with only a bit of a dip in front of the sink. (If my memory serves, I don't remember there being a lot more cross members in other 70s Airstreams either.)

I've read here that others used cork underlayment to "even out" the floor beneath the laminate where needed. (I would guess that you could also double up on the thin foam sheet that typically goes under a floating floor.) Installing that laminate running along the major axis of the trailer is also supposed to help remove some of the "bounce" in the floor. I haven't tried doing this yet, but intend to follow that plan this winter/spring when we put in either floating cork or Marnoleum Click.

Other options? I had a restorer suggest putting a thin plywood layer over the whole floor and then using sheet Marnoleum (mainly to even out the rivet/joint lines), but again, I'm not interested in adding a substantial layer of something that could rot. Finally, I guess you could use a levelling compound if things were really bad, but I'd think that would crack with travel.

Given the limitations of time and funds, you could try the least invasive approach first. If it goes bad, you're just out the cost of the flooring material, which isn't really all that pricey.

Tom

[overlander64]

I was fortunate in that my Minuet had minimal sag in its composite flooring, and I can report excellent results with Armstrong laminate flooring with a double layer of Armstron Quiet Step underlayment below the floor -- essentially a tripple amount of cushion as there was a built-in pad on the laminate flooring panels themselves. This installation has been in-place since 2005, and still cleans up to look like new.

Kevin

[mutcth]

Kevin, did the seams remain tight and hard-to-see in your installation? We've seen a trailer or two with laminate floors with very visible seams.

I guess this could depend on the specific flooring....

Tom

[joe77]

Cameron, Yeah I'm kind of worried that with a large sag the hardwood or cork floating floor i'm installing wont work.

[tallytwo1994]

If you feel there is inadequite support then isn't it a better idea, and use of resources, to try and fix this problem first? Couldn't you remove the belly pan in order to install additional cross members, instead of removing the whole interior and the aluminun flooring?

Carol

[cameront120]

Originally Posted by joe77

Cameron, Yeah I'm kind of worried that with a large sag the hardwood or cork floating floor i'm installing wont work.

Then the problem would be with floors having seams. If you put down a sheetgoods flooring like linoleum, sheet vinyl or cork, rather than laminates or hardwoods, the flex in the floor would have little impact on your flooring. Where flex is going to be a problem is where your flooring has multiple seams which will be prone to damage and separation by the flex in the floor. I guess what I'm saying is choose a floor that won't be affected by the flex.

[overlander64]

Greetings Tom!

Originally Posted by mutcth

Kevin, did the seams remain tight and hard-to-see in your installation? We've seen a trailer or two with laminate floors with very visible seams.

I guess this could depend on the specific flooring....

Tom

There is only one seam in the entire installation that isn't nearly invisible. It lays down perfectly in the winter when heat is used in the coach . In the summer, with heat and high humidity the seam raises above the level of the abuting pieces - - this particular seam is immediately in front of the refrigerator and may relate to the way in which the refrigerator is attached to the floor.

Arlene and Henry Fowler of Fowler RV Interiors (Symsonia, KY) handled the installation of my floor coverings. This was the sixth season for this floor covering and it still looks new with minimal care . . .

Kevin

[mutcth]

Originally Posted by cameront120

If you put down a sheetgoods flooring like linoleum, sheet vinyl or cork, rather than laminates or hardwoods, the flex in the floor would have little impact on your flooring. Where flex is going to be a problem is where your flooring has multiple seams which will be prone to damage and separation by the flex in the floor. I guess what I'm saying is choose a floor that won't be affected by the flex.

I would agree with that, but there are a few more issues that need to be addressed when putting a floor in a Minuet. You need something that can smooth over the rivets and seams; otherwise they can "telegraph" through the flooring.

Multiple Minuet owners have successfully used a floating floor instead of carpet.

Tom

[cameront120]

I agree that an underlay would be required, but it would need to be a product that isn't so soft to allow the rivets and seams to 'telegraph'. One product I just thought of that might be ideal for such an application is an uncoupling membrane such as that made by Schluter:

Waterproofing, Uncoupling and Drainage Membranes - Schluter-Systems

With all the voids in the membrane, rivet heads would likely no longer be a problem.

[mutcth]

Interesting stuff!

A curious question though: if you went that way instead of a floating floor, wouldn't you need something rigid to adhere the sheet material to?

Tom

[cameront120]

Originally Posted by mutcth

Interesting stuff!

A curious question though: if you went that way instead of a floating floor, wouldn't you need something rigid to adhere the sheet material to?

Tom

The membrane would also float and the finished floor on top would act as ballast, to keep everything where it should be. I could see the Schluter product being laid down loosely with the floating floor applied over top of it. I'm just thinking of the orange membrane as a possible underlay that would have the rigidity to keep seams and rivets from telegraphing. I suppose that your finished floor could be glued to this membrane to form a floating 'system' that combines underlay and finished floor. I'm just brainstorming here.

Edited to Add: The product I linked to shows the whole system of grouts, membranes and tiles, etc. What I'm considering as a viable option is just the orange membrane itself as an underlay. The rest of it wouldn't have application here, as grout and tile would not do well in a moving trailer.