How would you frame out this flooring?

[TucsonAZ]

So a HUGE part of living in such a small space for me is air quality. As such, I'd originally intended on doing the floors like Chuck with PureBond NFA plywood but I can't easily find it and it's super costly where I can.

This has me thinking I'm just going to use T&G 1x6 stock but then I'm left in a position where I can't really glue the insulation down and glue the T&G to that. Since I'll be using 1x6x12s I could do the boards front to back with wood to mechanically tie into every 4 feet as well as the glue but running side to side seems to make more sense.

Have any of you used tongue and groove on the floors and if so how did it go and do you have any pictures?

[LargeMargeInBaja]

2003, we laid one-inch pink-board on the box floor.
We painted marine plywood on all surfaces to seal, then laid it on the pink-board.
Our visible floor is slate in the center with a bamboo perimeter.
No frame, no fuss.
.
Two decades full-time live-aboard.
Zero degradation of the pink-board from the abuse of dogs and two adults... (plus a frequent yummy third!).
.
An aside.
We heat using a Wave 3 catalytic heater.
They are a poor heater of air, they work best heating something.
On our heater's stumpy legs, it heats the slate, then that radiates into the room.
.
An aside:
Warm slate on a chilly 2AM trip to the head...

[TucsonAZ]

Anybody else have any thoughts or ideas on this one? I'm really trying to avoid plywood at any and all costs.

[Rucker]

I missed the reason why you're trying to avoid plywood-can you explain?

[HamSkoolie]

3/4" T&G plywood over 1" or more (depending on how much vertical room you need) closed cell foam insulation (owens pink is perfect). Glue the foam down with the appropriate (foam compatible) adhesive then lay the T&G plywood over it. Chucks stuff is good but if you can't find it you can't.

The T&G will keep joints between sheets from lifting. Do paint the ply on all sides to prevent moisture damage should you get a leak that goes unnoticed.
And there is no need (as chuck says) to frame in the foam panels.

[TucsonAZ]

Originally Posted by Rucker

I missed the reason why you're trying to avoid plywood-can you explain?

I don't want to deal with the chemicals and the off gassing. There are NFA plywoods but they're costly and harder to find. For example, best I can see PureBond is currently only sold at one Home Depot in California. Given the bus is a small, enclosed space I'm only willing to do natural products.

There are some other reasons but those are all more minor.

[Rucker]

Originally Posted by TucsonAZ

I don't want to deal with the chemicals and the off gassing. There are NFA plywoods but they're costly and harder to find. For example, best I can see PureBond is currently only sold at one Home Depot in California. Given the bus is a small, enclosed space I'm only willing to do natural products.

There are some other reasons but those are all more minor.

Gotcha. My build has about a thousand other things in it that are more dangerous than plywood, so I wouldn't know where to start.

Electronics, which heat up and probably burn off the chemicals used in manufacturing, which efficiently circulate through the vent panels of the devices into my conditioned air space; specialty tile grout; sealers like RedGard; caulking; paint; any number of foams and plastics; wire coatings; Pex piping; solder on copper piping. Not sure I'd know how to swap those out for something less environmentally risky.

The good news for me is I built the bus over three years, and every summer the inside temperature always crawled up above 110 during the afternoon; so whatever crap there was to outgas, it outgassed.

Maybe come do your build in Cali in the summer!

[Rucker]

Actually I just remembered you are in Tucson! Just leave the plywood out in the sun a few days?

[TucsonAZ]

Originally Posted by Rucker

Actually I just remembered you are in Tucson! Just leave the plywood out in the sun a few days?

Nothing you're saying is wrong but for me, plywood is just nasty and while 50% plus will off gas it still takes forever for the rest. In my enclosed trailer I bought plywood in Nov, left it to air out in the yard for 3 weeks, then cut and painted it, then put in in my trailer and covered the floors with diamond plate and I can still smell it. Fine for my trailer but not for where I could be living for extended amounts of time.

Everything off gasses including softwoods, for me it just comes down to what, how much, and for how long and for that reason no plywood. And I use Chemlink M1 for all caulking and sealing.

[Rucker]

Is there a particular chemical that outgasses?

[TucsonAZ]

Originally Posted by Rucker

Is there a particular chemical that outgasses?

Benzene, toluene, styrene, and formaldehyde would be the worst offenders.

[DeMac]

Yes, plywood does off-gas, but the off-gassing timeline is steep -- 60% of the formaldehyde evaporates 30 days after production. Urea-formaldehyde takes much longer than phenol formaldehyde to offgas and will continue (slowly) for 10-20 years.

The EcoDesign Foundation 5 cautions that glues used in plywood manufacture can have emissions which are potential health hazards. Interior-grade plywoods contain urea formaldehyde glues which outgas at room temperature, while the phenol formaldehyde glues used in exterior grade plywood do not. The Foundation says that many architects, therefore, specify exterior grades of ply for interior use."

Encapsulating the sheet in Safecoat, or a similar product, ought to slow the offgassing process.

"AFM Safecoat SafeSeal: A multi-use, water based, low gloss sealer for highly porous surfaces such as particle board, plywood, processed wood, and porous concrete. Used primarily to reduce toxic outgassing: in particular, it is highly effective at sealing in formaldehyde outgassing from processed wood such as plywood, particle board, and pressed wood. Safecoat Safe Seal is virtually odorless on application and odorless once cured. For interior use."
afmsafecoat.com


Hindsight:
Purchace, Coat & Store plywood for offgassing, 30 days prior to installation.

[Rucker]

Another angle to this dilemma is designing very good ventilation and air filtration. Have you thought about that part of the build?

[HamSkoolie]

The off gassing of plywood as a health concern seems deminimis to other hazards such as from fuel used to power the rig, the foam used in seat cushions including driver and passenger positions, couches, mattress, etc.

Any sealants or adhesives used will off gas.
All plastics.
Try a new car, or even an old one.
Yes, toxic chemicals are off gassed from a lot of things but their levels and nothing compared to the normal everyday toxins we are all exposed to. Everything from drinking water (which is ALLOWED to have things like Arsenic), to cleaning supplies and even the air we breathe all have toxic elements. Yet somehow we live.
Unless you're rig is going to be air tight (which has been a code requirement in homes) the exchange of air will remove off gassed toxins.