So I have been doing a lot of research and getting scraps and testing them and have settled on AdvanTech waterproof plywood. Anyone use it before?
Locally it is $22 for 3/4 T&G sheet which is cheap!
My plan is to use 3/4 on the bottom then a couple inches of closed cell foam board then a 1/2 on top. > http://www.rmax.com/products/wall-products/thermasheath-3/#tabs-2 (http://www.rmax.com/products/wall-products/thermasheath-3/#tabs-2)
Any advice from anyone who has done a plywood foam sandwich floor?
https://www.youtube.com/playlist?list=PLD4DABC7254437F2D (https://www.youtube.com/playlist?list=PLD4DABC7254437F2D)
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something like this > http://winterfarmbus.blogspot.com/2011/01/insulation-and-sub-floor.html (http://winterfarmbus.blogspot.com/2011/01/insulation-and-sub-floor.html)
I lucked out, my transit has 1" plywood with 1/4" rubber mat bonded to it. No additional insulation. Plywood in itself insulates well. I would stay away from a sandwich floor. If you want insulation, spray foam from underneath. Good Luck, TomC
http://www.bobvila.com/articles/526-enhanced-plywood-and-subfloor-products/#.VgBKpsrD8v4 (http://www.bobvila.com/articles/526-enhanced-plywood-and-subfloor-products/#.VgBKpsrD8v4)
I second Tom on this. There shouldn't be any need for additional insulation if you have an inch or more of good plywood, unless you live somewhere really really cold. However, good is the operative word here - crap plywood probably won't hold up or will be so knotty as to be worthless. FYI, I have 3/4" of marine ply, a layer of what looks like tar or bitumen, another 3/4" of marine ply, and 1/8" Armstrong rubber flooring, and it insulates just fine. You'll also lose headroom with unnecessary floor thickness.
John
Plytanium here. Waterproof coating on the luggage bay side and we coated thick with poly on floor side
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Well part of the reason I dropped the floor in my 4106 8" is to allow more room for serious insulation ( as well as I like the feeling of the taller ceiling and I have tall relatives)
The two rear bays will be insulated the rest will be uninsulated. I have allowed for 3" of closed cell E85 icynene spray foam ceiling , walls, which will give me around R19.5
Plywood only has 0.95 R per inch on a good day so it could be a big loss of heat/cool without something isolating it especially conducting to the metal floor supports.
I sandwiched 1 inch blue board between 2- 5/8 pieces of plywood it made a lot warmer floor in Wy and Idaho,I was told it had a R value of around 9 the floors can get pretty damn cold in a bus.
The next bus had a Nuheat floor heating system I loved that gadget
Quote from: luvrbus on September 21, 2015, 12:41:05 PM
I sandwiched 1 inch blue board between 2- 5/8 pieces of plywood it made a lot warmer floor in Wy and Idaho,I was told it had a R value of around 9 the floors can get pretty damn cold in a bus.
The next bus had a Nuheat floor heating system I loved that gadget
+++Clifford, That is what i was hoping to hear. I should be at 14 R with my current plan.
The stuff shown in those photos isn't plywood - OSB is cheap and has it's uses but I'd never use it as an alternative to proper plywood for a floor myself, except perhaps if I was just sheeting-out a domestic loft or something
Jeremy
I would only use marine plywood.That stuff is basically flake board and moisture "resistant". Don't cheap out now with all the work you're doing. Plywood retains fasteners better also. jmo
If you sandwich I was told you need the screws long enough to go through both pieces of plywood and the foam to what ever you were attaching to that is what I did I had no squeaks and was rock solid
I like AdvanTech. I want some for a project, but I can't find anyone locally who seems to carry it. I would compare weight between AdvanTech and plywood subfloor. Plywood might be lighter.
You seem like you are totally re-engineering and rebuilding your bus. I hope you don't end up spending 10 years on it and never get it done like some.
Quote from: belfert on September 21, 2015, 03:51:10 PM
I like AdvanTech. I want some for a project, but I can't find anyone locally who seems to carry it. I would compare weight between AdvanTech and plywood subfloor. Plywood might be lighter.
You seem like you are totally re-engineering and rebuilding your bus. I hope you don't end up spending 10 years on it and never get it done like some.
These guys have it in your area> http://www.shawstewartlumberco.com/about-shaw-stewart (http://www.shawstewartlumberco.com/about-shaw-stewart)
Regular plywood absorbs water and supports mold, no way I would use it as a floor with out several coats of sealer = too much work
Im doing my best to finish it, I am in the process of ebaying my previous lifestyle to buy materials to build the bus.
If by 'regular plywood' you mean cheap interior grade stuff then yes it does, but that's obviously not what you'd use for a floor. I don't know about the American market but here 'flooring and roofing' grade plywood is widely and commonly available and would be much better (stiffer, stronger and more durable for a given thickness) than OSB. The reason that OSB is cheap is that it's basically bits of scrap wood squashed together with glue - but lots of joins and no long fibres mean poor structural properties
Not to labour the point, but if cheap OSB was satisfactory for a bus floor then the manufacturer would fit them as standard. But they don't, they use plywood
Jeremy
The AdvanTech is more like plywood than OSB and from what i have seen it is stiffer than plywood. I refuse to use regular OSB for anything. The AdvanTech also is formaldehyde free which i think is important for indoor use. https://www.youtube.com/watch?v=ceFc-02r9J8 (https://www.youtube.com/watch?v=ceFc-02r9J8)
Manufactured wood panels have their place, but most assuredly NOT on a vehicle floor. My '86 Airstream trailer used something like you are talking about on the floor - absolute trash. Have you any idea the difficulty involved in replacing that crap?
Lots of building products test well in the laboratory, but don't perform nearly as well in the real world.
As has been said, Marine grade plywood is one of the best choices you could make for your floor.
The biggest problem with a manufactured wood panel (or what ever you want to call shredded wood & glue pressed flat ) is that more often than not, they are not as tough & durable as a good quality piece plywood when subjected to real world conditions.
There are also some aluminum skinned plywood panels also available, but those usually make the marine grade plywood look cheap. :o
For reference, my '87 Newell has plywood on the floor with foam insulation sprayed on the bottom. Still ROCK SOLID.
I haven't had it in the cold yet, but it is insulated well enough that 1 roof AC can easily keep it cool on the hottest day this past summer.
Good luck with your project.
PS, the foundation of any project sets the tone for everything that follows . . . .
Over the years I seen a lot of buses and high end motor homes like a Newell the floor was rotten made with marine plywood,you have to take great pains on the installation of any type sub flooring and keep it dry
the down side with plywood is it delaminates . when it does its toast .
dave
Quote from: sledhead on September 22, 2015, 04:32:12 AM
the down side with plywood is it delaminates . when it does its toast .
dave
Isn't delamination a failure of the glue joint? So that should apply to any glued product.
I remember all the hype about FRP siding being such a great & perfect improvement over the 'ugly' riveted alum panels - - - - Too bad the real world results didn't match the sales hype . . . . .
It has been my observation that when plywood delaminates, it doesn't loose all of its strength. The pieces of wood are still large enough to provide some support. With the smaller pieces used in 'engineered' wood products . . . .
As with anything, abuse & neglected maintenance usually leads to early failure.
If you could only keep it dry. . . . .
Your project, your choice. Hope that whatever you choose to use works as you intended so you can spend more time enjoying it !
From what I've seen, the engineered wood products are harder, where, in comparison, the plywood has a little bit softness. Ie: easier to walk on, not as harsh.
Doing more research... from what I understand the binder resin is similar to gorilla glue.
I did find this, it is a pice that has been exposed to the weather untreated for ten years, its actually a door to a contractor dumpster.. >
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Plywood is a engineered wood also isn't it,I have watched it made in Oregon they have strips glued to make a sheet 4x8 of veneer then they keep stacking and gluing the sheets to the desired thickness only difference in any plywood is the glue and the top sheet of veneer.You have to keep both products dry and seal the edges but I never saw OSB used in RV it maybe ok it's all they use in houses now
It doesn't matter so much what the floor is made out of. What matters most is to keep it dry. Most materials will last a long time if kept dry.
JC
The term 'plywood' covers everything from cheap sheeting made with softwood and PVA glues, right up to and including materials made of hardwoods and modern resins used to construct aircraft and racing yachts. I used to build boats and wince (in an entirely pretentious way) when people use the term 'marine plywood' when they actually mean 'exterior grade ply bought from my local timber merchant'. True marine ply is quite hard to get hold of and hellishly expensive, and has to comply with BS1088. I've actually just looked on Wikipedia to see what the equivalent American standard is, and there isn't one - apparently the code to which different grades of plywood are manufactured to is entirely voluntary in the States, which might be why the product seems less highly regarded and/or less commonly used
Jeremy
Oh, and that dumpster door will be heavier and floppier than a heavy floppy thing.
We have all kinds of marine plywood manufactures here that meet the BS1088 specs the better grade is Lauan board laminated together with what ever veneer you choose, 1088 is the same code number we use here for marine plywood some here use code 6566
Forest Products ships marine plywood all over the world I saw a whole 53 ft container full of their Aquatech 1088 going to a yacht builder in Asia
Quote from: lostagain on September 22, 2015, 07:08:17 AM
It doesn't matter so much what the floor is made out of. What matters most is to keep it dry. Most materials will last a long time if kept dry.
JC
I had a few leaks around edges and corners of my floor downstairs. When I looked, I found that the original plywood floor was rotten in places and delaminated. I had to replace it all. I put coats and coats of sealer and sealer paint - esp. on the edges - of the new plywood, even though it was exterior grade ply. I also went from 1/2" (equiv.*) to 3/4" (equiv.) -- much better.
(* Equiv. = whatever they sell now that is supposed to be the "real" thickness but isn't.)
if it's wood...it needs sealants.
chip board will drink a lot of it >:(
There seems to be a consensus -
1 - use good quality
2 - keep it dry
3 - use sealants & paints if you can't keep it away from water
;D ;) ::)
I use both all time and have yet to find an OSB that holds fasteners as well as plywood. We are allowed to use OSB for flooring now but if I can get the client to agree I upgrade to ply. I agree that keeping it dry is the most important, but the truth is water will do what it does so...I prefer ply, it will eventually fall apart but OSB punks out much faster. No matter how well you seal a surface there will be screws etc to let water in. Also along the wall edge a certain amount of condensation should be expected unless you engineer the connection very carefully against thermal bridging.
Interesting thread though as the OP seems pretty convinced already that OSB is the way to go.
I used the 3/4" AdvanTech over the original plywood bus floor. It was installed in 2008 and has survived more than one water mishap, It still looks new in places where you can still see it. It is a quality product IMO.
Quote from: buddydawg on September 23, 2015, 09:35:01 AM
I used the 3/4" AdvanTech over the original plywood bus floor. It was installed in 2008 and has survived more than one water mishap, It still looks new in places where you can still see it. It is a quality product IMO.
I don't believe you. You need to attend the NonRally to prove it. ;D :o :P
Been way too long
I found two un-inclosed trailer manufactures that use bare Advantec on their trailer decks, one of them is for transporting river rafts and these trailer sometimes get backed into the water. I think I am going to try it and I will report if there are any issues. However i still reserve the right to hate on regular OSB..
Quote from: Darkspeed on September 23, 2015, 10:36:37 AM
I found two un-inclosed trailer manufactures that use bare Advantec on their trailer decks, one of them is for transporting river rafts and these trailer sometimes get backed into the water. I think I am going to try it and I will report if there are any issues. However i still reserve the right to hate on regular OSB..
I bought a 16' flat bed trailer - the deck was 2 x 6 southern yellow pine - painted. Looked real nice, but didn't last 5 years. Replaced with pressure treated southern yellow pine, no paint or any other type of water repellant - 15 years later it is still solid.
I hope the advantech holds up as well - will be nice to have that as a suitable option. But not gonna hold my breath . . .
Ok. You guys convinced me. I'm using composite wood decking in my next bus.
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Just move to AZ then you need to add water to keep it in good shape ;D
And the bubble bursts.
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I noticed that they spend a few sentences about how well they seal the edges. What if you have to cut off the edge to fit it? It is water resistant, not water proof.
Quote from: chessie4905 on September 23, 2015, 02:51:49 PM
I noticed that they spend a few sentences about how well they seal the edges. What if you have to cut off the edge to fit it? It is water resistant, not water proof.
simple dimple... just cut the middle out ;D
Quote from: chessie4905 on September 23, 2015, 02:51:49 PM
I noticed that they spend a few sentences about how well they seal the edges. What if you have to cut off the edge to fit it? It is water resistant, not water proof.
What I was told is the entire panel is compressed at high pressure and the resin is waterproof and the chips are saturated in it before they are compressed so any pice is as water resistant as the whole.
If you're asking about the composite, it apparently has a very very low water absorption rate. Like waaay below typical wood. So yeah. Maybe seal the cut edge and sleep good
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Just to mention that the water absorbability of wood depends upon the wood. Softwoods (fast-growing and therefore cheap and used in all these reconstituted products (chipboard, fibreboard, strandboard etc)) generally absorb water like a sponge and need special efforts to seal them. Hardwoods generally absorb water much less, and some hardwoods (eg. teak) are traditionally used in marine environments without even being coated. In fact teak is so naturally waterproof that the oils it contains prevent coatings from sticking properly. And yes, you can buy teak plywood, but you'd need to rob a bank first.
Jeremy
Quote from: Jeremy on September 24, 2015, 01:31:56 AM
Just to mention that the water absorbability of wood depends upon the wood. Softwoods (fast-growing and therefore cheap and used in all these reconstituted products (chipboard, fibreboard, strandboard etc)) generally absorb water like a sponge and need special efforts to seal them. Hardwoods generally absorb water much less, and some hardwoods (eg. teak) are traditionally used in marine environments without even being coated. In fact teak is so naturally waterproof that the oils it contains prevent coatings from sticking properly. And yes, you can buy teak plywood, but you'd need to rob a bank first.
Jeremy
That's what I am talking about here in AZ we keep water in the sink to protect our Teak wood and it's not plywood then she uses some special oil once a year
I made the journey to Tampa to get my hands on some 3/4 T&G Advantech board today.
It has a very smooth surface with almost a plastic feel. There are no voids or depressions around the individual chips, it looks like resin and wood were compressed solid and then milled - i.e. you cant feel where the chips are. - so far so good
In defense of OSB: We put a 20 ft electric gate at the entrance to our property. The normal procedure would be to lay a concrete slab for the track for the gate to roll on. I got lazy (as usual) and just put down some painted OSB and mounted the track on that. The gate has 2 wheels about a foot apart. One is a grooved wheel that rolls on the track. The other is a solid rubber wheel that rolls directly on the OSB. So this board has been sitting in the desert through sun and storm for over a year and is still doing fine. How many years would it take as an floor underlay to equal that abuse?
Have you considered MDO (medium density overlay) or HDO (high density overlay)? MDO has been used for highway signs and HDO is used for concrete forms. MDO comes in single sided or double sided.
Bandsaw.
I'm going to resurrect this thread for future searchers. We have done months of research on Advantech and indeed it is the ultimate floor for a coach conversion bar none. We installed two layers of it with spray foam in between in our coach. It is basically lifetime waterproof. It isn't typical OSB and shouldn't be even discussed in the same category. They basically take the individual chips, pressed at high pressure with waterproof resin/glue and form the boards. Straight, flat almost laserlike edges. Absolutely amazing stuff to work with. A cut edge is as waterproof as a non cut edge. 500 day water proof guarantee. Literally, you can cut a piece, put it in a bucket of water for two years and it will not soak up any of the water. Awesome stuff.
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Scott,
I am planning on building a house(the fixed to the ground type--not mobile) next year, and all the builders are using Advantec for flooring, exterior sheathing, and roof deck. They stated you could use exterior plywood, but it is not as good as the Advantec. I am from Missouri, so I will be doing my own tests first.
Steve
Steve, cut a square, stick it in red dyed water. Submerge it. It won't soak it up. If it's genuine Advantech I promise you.
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well a year and a half of no windshield in the bus and some rain coming in, I am still VERY happy with the AdvanTech waterproof plywood.
It was uncoated all of that time. I just went back and put a coat of oil based porch paint on it and it is solid as a rock.
I took a scrap of it a year and a half ago and put it in a know termite nest and just recently digging it out of the ground it was discolored, had a few flaking fibers, but was still structural and uneaten!
(https://www.busconversions.com/bbs/index.php?action=dlattach;topic=24673.0;attach=27443;image)
When it's your vibrating flexing living space the less voc toxic glue the better, looks like advantec/chipboard has a lot more glue vs marine plywood. :(
Depending on your type of bus and climate, you can use whatever you want; but for the time and effort?
For my new bus floor living in Oregon in a 4103, I am choosing Marine plywood.
I am even considering slightly tilting the floor toward the exterior, leak proof ;)
http://www.christinedemerchant.com/marine_plywood_grades.html (http://www.christinedemerchant.com/marine_plywood_grades.html)
The glue fumes haven't killed me yet. And it hasn't killed the thousands of people living in homes in California that are using it. I'm much more likely to die if a myriad of other things than the glue impregnated in my wood floor which is sealed underneath a solid unseamed sheet of vinyl glued to it. It doesn't take any more time nor effort to use Advantech. I wish more people would use it because it seems that the floors on most campers gets soft and is the first thing to rot out.
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Yea, depends on your allergies and the state of you immune system, my mother in law bought a new thor which makes her swell up like a balloon.
After first camping trip of 3 days in Carolina she went to emergency room, then after 5 day cross country she was admitted in Oregon for a week.
As the doctor put it she is slightly above rock bottom and any small thing like formaldehyde gas can bring her to rock bottom, your choice.