Coosa composite floor

[jmonk]

Frame is at the welder. Figuring things out as I go. I spotted a thread titled "subfloor material" that's a couple years old and wondered if there was anymore personal testimony regarding the coosa composite panels mentioned there in.

Plywood seems to be the norm but much of what's being done in the RV industry also seems to be based on historical use rather than new possibilities. That said, particle board was once the "building material of the future".

One downside of the coosa panels seems to be availability or ease of acquisition. I can't seem to find a price very easily either, not that I've spent gratuitous amounts of time trying.

[pdavitt]

Coosa is used a lot in the marine industry. You might have some luck with the boat/ship yards around Charleston.


Pat

[GMFL]

It’s made about 1:30 min from my house. It’s great stuff.

[mikextr]

Coosa is a great product. When I was considering it, the cost was about 6 times higher than the plywood I ended up using. About 300 for the Coosa vs 50 for the plywood that was readily available at my local lumber yard. I decided Coosa was not for me since I needed 6 sheets.

[skyguyscott]

The main downside of Coosa really is the cost; it is way more expensive than plywood. But if you look beyond the cost of materials, consider:

What is the cost in time and money of redoing the floor again, once mice, bugs or water ruin it in about 10 years or so? I had to replace plywood sections around the door and wheel wells twice in 15 years, done at the factory. That was big $$$. Seems to me, the material cost is just one relatively small factor in the larger equation.

The benefits in lighter weight and water resistance and peace of mind are worth it to me.

The only other thing with cossa is that it does not hold screws as well as plywood; what little you might need to secure to the floor itself is better secured with bolts and nuts. Most items can be secured to the walls.

With the internet and delivery options available today, finding and getting Cossa is not difficult. Here is a sample link, there are other suppliers as well:

https://www.boatoutfitters.com

No one doubts the superior properties of Cossa, it's the cost they take issues with.

[jmonk]

It sounds like most are right where I'm at; hoping to find someone who has used the stuff and can attest to its cost effectiveness. I'm fairly certain that yes, the coosa panels are superior to plywood, maybe even far superior.

So the question becomes; how can installation, both of the floor and proper installation of the shell, increase the longevity of plywood?

Can epoxy coating the plywood and re-sealing possible intrusion points increase the lifespan of plywood enough to rival the coosa? Probably not.

Another factor in my experience with wood framed trailers is frequency of use. Leave that box trailer sit for a year and see what happens. Leave it sit for a few years and haul it to the dump. That may not be true in all climates, but here in coastal South Carolina it's a pretty bad idea to have one if you're not going to be in it regularly.

Running HVAC could, by virtue of keeping things dry, extend the life of wood, but that does come with a cost. You have to be able to power your trailer (installation of an electrical connection) and then there's the power itself.

The only way to answer all the questions is to spend the money and wait for results.

I do think it would make a lot more sense for someone building them for resale, especially if they're producing large numbers of them (Jackson Center), to absorb the expense.

A guy like me doing his own rebuild has a lot tougher time eating a couple thousand dollars than a company building hundreds of trailers a year and the person who is already spending $150,000 may not have as tough a time spending 2 or 3 thousand more for a coosa floor option.

Then again, I find it very hard to believe that Airstream hasn't considered this yet they still haven't tried coosa floors. Even if it's just rationalization on their part I'd like to know what their reasons are aside from the expense. They had to consider other variables in the equation. I can't help thinking there's an element of "we've always done things this way" in there somewhere, just like the mini-split discussion. Why aren't we seeing those from manufacturers?

[Isuzusweet]

As a well known hugh fan boy of Coosa, I can give testament to how easy it was to work with; its strength and the peace of mind knowing that no matter what accident happens, be it a window left open, over filling a water tank, or a water pump left on and a fitting letting go; my subfloor would be intact and undisturbed by the carnage.

The extra cost of epoxying the marine plywood, only to compromise that shield once you put a screw through it, doesn't make sense to me. Any moisture that enters that hole, or end grain, will only have that exit to get out of. Should moisture continue to be present, the moisture will eventually travel throughout the plywood subfloor, causing it to rot from the inside out, as the epoxy shield won't allow moisture out.

As for screwing things to Coosa I used a number of different technics like Premium Nails adhesive aluminum L channel to the Coosa board, and then screwing sofa's down through the aluminum. After five years, not one mm of movement.

Yes, more expensive than regular plywood; not much more than marine plywood, but lighter, stronger, and will not rot.......ever!

Cheers
Sidekick Tony

[jmonk]

Thanks Tony, this kind of personal and practical experience is very convincing.

[skyguyscott]

You raise a great question about why Jackson Center doesn't install Coosa Board to begin with, using their power of volume to decrease the cost and improve the product.

Well, as any long-time observer of Thor may tell you, that's just not how they roll. They will eventually add features to AS that customers will see and pay for, shinny, visible cosmetic changes, and gee-whiz features like automatic awnings, and WiFi connectivity, but to spend money on invisible structural improvements, I have not seen it.

They could improve the floor (some SOBs even have aluminum floors) they could add wiring conduit, use more effective insulation, use carbon fibre elements, and probably a host of other real improvements, but any that increase manufacturing costs, they don't do.

Consider that the Dometic appliances they install in AS are not Dometic's top-tier products, but their cheapest! (they recently gave end customers option of installing higher end ranges at a premium markup). AS once had slick custom, forged aluminum exterior power outlets that closed flush with the body, now they slap on plastic generic RV industry warts all over the body -- because it's cheaper.

Also, in a perverse sort of way, Thor has a vested interest in "planned obsolescence" AS trailers already last far too long as is. Imagine how much more money they could make if they could sell more, or at least earn off repairing/refurbishing/restoring older units.

Make the business case to Thor for improving the floor, and something positive may change.

[vintageracer]

Take a look at JM Huber "Advantech" flooring material available at your local Home Depot/Loews.

It's sub-floor material for homes that is also a much better choice over plywood. It's cheaper than Coosa and more expensive than plywood. Middle ground if you will!

Advantech is VERY waterproof/water resistant sub-floor product. I have had a piece of Advantech flooring board sitting in a barrel of water for over year and nothing happened to it. No swelling, no splitting, no deterioration.

Another alternative to consider.

[jmonk]

Been busy and haven't made time to post, sorry. One consideration or maybe concession in the discussion around why Airstream hasn't offered coosa flooring could be the fastener issues. They can be overcome as we've seen in our discussion, but not without increasing assembly time; not exponentially but substantially I'm sure. Look at any number of automotive fasteners that have evolved around the assembly process rather than the removal and replacement process. Ever change a fuel pump on a modern vehicle? Fuel lines go together without tools, but getting them apart is a different story. A couple screws holding an object in is different than fabricating multiple parts, adhering them, and then installing said item. I'd do it on the trailer I'm working on, but I'm not working on more than one trailer or working on a deadline to get it completed for sale.

I'm not defending Airstream's apparent lack of interest in new floor materials, just making an observation.

The other thing that I'd like to know a little more about is the Advantech product. I think I've spoken to someone about it before but I can't remember if it was Advantech or not. The product I was looking at was supposed to be far more water resistant but also more dense. It looked like OSB but that's not what it was. Does the Advantech weigh substantially more than plywood?

[vintageracer]

Originally Posted by jmonk

Does the Advantech weigh substantially more than plywood?

Yes Advantech weighs more than plywood however not substantially more. Being an engineered product it looks a lot like OSB HOWEVER that's the only similarity. The additional weight comes from the resin used to combine the fibers into the board.

Great stuff!!!

Here is a link with all the information about the product including sheet weights, moisture resistance/comparisons and all sorts of other WTF information.


http://www.huberwood.com/index.php/a...SAAEgJwX_D_BwE

[Aviator]

In our 1970 restoration, I used Marine Grade plywood, then applied West System epoxy to all sides before install. Where I drilled holes for the elevator bolts, I used a Q-Tip with poly inside the hole to coat it before installing the bolt.

I would call it a compromise solution. Less cost than the Coosa product, better than straight ply.

[skyguyscott]

Everyone will have to calculate their own situation. For some, living in dryer climates and with fewer years ahead than behind them, more plywood might just outlive their use of the trailer, especially if their original plywood floor had lasted decades.

For me, to replace the entire floor, the material cost of Coosa would be about $1300. Now, having JC do some plywood floor replacement of just a section or two of rotted plywood floor cost me $1800 back in 2005. (I got the trailer pretty cheap, so it still seemed like a good deal at the time, but I had not heard of Coosa)

Now, for me, if I add any flavor of plywood, regardless of coatings, I would always be concerned about any leaks or any standing water anywhere in the trailer, especially in areas I might not be able to see, say around the wheel wells, under the fresh tank or under the black tank (69 Caravels have the tanks above the floor, under the couch, and under the toilet in the rear corner)

With Coosa, any water anywhere, be it from leaky windows, doors, vents, hatches, spills, condensation, pluming drips, whatever -- not an issue with Coosa. Once Coosa's in, the floor will likely never need replaced ever again. Rot? Mold? Insect infestation? Mice food? Not with Coosa. Ever. That's peace of mind, at least for me. And it's 30% lighter than plywood! And it's just as easy to work with (not counting the screw issue, which is easily worked around). Only downside? Mo Money, but I feel you get more than what you pay for.

[jmonk]

I'm leaning pretty hard toward coosa now. Largely because of application. We're installing a mini split system and coolant lines will run on the interior over the wheel wells. The possibility of condensation is there so it's likely that water will end up on the floor. Ideally it won't see standing water, but ideally none of these trailers would leak and there would never be plumbing issues, and condensation wouldn't be a problem, and...

Then there's the weight thing as added incentive. That's substantial to me considering I'm using over six sheets of this stuff.

The screw issue can be dealt with and in parts of my application may be completely irrelevant anyway. Much of my interior (bedroom and living room) is intended to be modular/removable and the plan is to use fasteners that will accommodate hex bolts. They'll be permanently installed in the floor once their location is determined. This was the plan even when I hadn't considered anything other than plywood. Some tie down points may be incorporated as well but they'll be through bolted to the floor. The difficult part for me will be making it look like something other than a cargo plane.

[skyguyscott]

[jmonk]

Not sure if anyone is paying attention to this string anymore or not, but I've done considerably more homework and Coosa is probably the way I'll go. Here's what I've found out.

Coosa does come in 5/8 thickness although 3/4 is far more common.

Coosa Bluewater 26 is the one for one replacement for 5/8 plywood however, Bluewater 20 will work if you're floating a laminate like Pergo on top of it.

The difference between 20 and 26 is the force with which the material is compressed. 26 is much stronger as it's manufactured with greater pressure. This is done to prevent compression of the product when using bolts. It's also stiffer which is part of the reason you would want to use 26 if you're just floating carpet or linoleum type laminate flooring. 26 is also much less likely to dent of something heavy is dropped on it. The alternative of 20 makes sense as long as it's covered with something stiff and strong. Otherwise it makes much more sense to go with 26. I may still go with 26 however because the difference in cost is only about $30 a sheet which isn't much considering the total cost at 7 sheets.

The price I've been quoted is Bluewater 20 at $183 per sheet and 26 at $213.

You'll have to find a distributor. I'll probably go with http://www.advanced-plastics.com/ . Their customer service is head and shoulders above the others I've spoken with. (Composite One and Donovan Marine) Most distributors are primarily concerned with people buying multiple pallets of something. The guy who just wants 7 sheets of Coosa board isn't really worth their time but that's not the way the Advanced Plastics rep treated me. I spoke to a rep at the Nashville branch, Tom I think.

All told it's much less expensive than I initially believed ($213 per sheet on the high end rather than $300).

The other conversation that I had with Tom at Coosa was regarding Airstream using the product at the factory. Tom said he's actually been to the plant in Jackson Center and it's the purchasing agent that drives everything. They're the ones who make decisions based on the bottom line rather than talking to engineers and marketing folks. That's the conversation that needs to happen. Perhaps if it were raised at a Jackson Center rally they might start paying attention.

They (airstream) would get the product cheaper than you and I so their cost would be substantially less than ours and in light of the cost of a new trailer it's negligible anyway; probably less than $1,000 per trailer.

Tom at Coosa fights the same battle with pontoon boat builders who are selling boats for as much as $250,000 and won't step up to Coosa for the deck. Boats are guaranteed for two years because the deck will likely start to rot in 3 on many pontoons. Purchasing agents for manufacturers would rather continue paying 30 to 40 per sheet for mediocre plywood at best than what they'd pay for Coosa. Engineers and Marketing people get it, but the decision isn't theirs to make.

[my3sonsdad]

I for one am following. Good info on the 20 Vs 26. Leaning towards floating vinyl plank flooring...but would much prefer to keep it light.

Total Plastics International also carries Coosa. They were a bit higher than a few others I contacted, but they have a location within an hour of me (Baltimore). For anyone considering using Coosa for other applications, there is also Nautical 15 which is significantly less but doesn’t have the rigidity of 20 & 26.

I need to go back through notes but most places seemed not to carry much of the 1/2” 20/26 in stock. My floors were originally 1/2” but I may go with 3/4” and route the edges.

One topic that I have trouble getting info on is painting Coosa. I understand it comes with a textured finish and most boat applications laminate it with fiberglass & resins. I’d like to be able to use it as a light weight cabinet finish material with an epoxy paint but not sure how that would look. All my existing cabinets were basically extruded aluminum and 1/4 laminated plywood.

[skyguyscott]

Great price on that Coosa! I was quoted $328 ea for some 3/4" Bluewater 26.

There's another member on here (i forgot the thread) who's doing his trailer in Coosa, including the cabinet frames, but I don't think he's painting them.

[jmonk]

I think I've used vinyl plank before and if it's what I'm thinking of you'd want to go with the bluewater 26 according to the guy at Coosa. The weight of the Coosa is at least 30% lighter than plywood so you'll have something to "trade" so to speak in your flooring.

I wasn't very clear in my one for one 5/8 plywood comment. The Bluewater 26 is intended to be a one for one swap in whatever thickness of plywood you're talking about so 1/2 inch bluewater 26 is supposed to be the same as 1/2 inch plywood. I asked about routing 3/4 inch down to 5/8 and was told it could be done with one caveat. As you remove material you get into the woven fiberglass mat and risk compromising the structural integrity of the Coosa. Tom said you'd probably be close enough to the edges that it wouldn't really matter, but I probably won't do it.

I didn't ask about painting coosa so can't even imagine what it might finish out like, but it takes a number of adhesives very well. We talked specifically about contact cement and formica for counter tops and that's absolutely fine.

We also talked about threaded fasteners for through bolts and it's best to glue them in but there are some adhesives that aren't particularly good. Tom seemed to think it may have been a compatibility issue with the coating on the fasteners though. It sounded like cure inhibition of some sort. You see that with silicone when it comes into contact with anything that contains sulfur. (latex and many modeling clays) I can't recall the adhesives he spoke of, but it wouldn't be tough to find out. Again, Tom didn't think it was a Coosa issue but the fastener coating.

He did say it will hold a screw, but for certain applications gluing the screw is recommended. I think he mentioned epoxy specifically and then pointed out that you'll be removing it in chunks if you do that and have to pull the screw out later. Finishing it with fiberglass solves some of those problems in the boat industry, but I'm not doing that. I liked the idea somebody posted about adhering aluminum to the floor and screwing through that if necessary. The contact cement would probably work well for that.

All in all I'm actually pretty stoked about this. I'm actually thinking of doing the entire interior sans wood. There are an awful lot of composite materials for every application.