2×6 T&G Pine as exposed subfloor + finish floor
paulmagnuscalabro
| Posted in Construction Techniques on
Hi All,
Question:
Anyone have experience using pine tongue-and-groove 2×6 boards as both subfloor and finish floor, leaving them exposed both above and below? Did you nail it or screw it? Glue it to joists? Did you finish it, and if so what did you use? Did you finish all sides or just the top? How’d it all work out?
Context:
I’m working on a gut/remodel of a 1960s shop/barn out behind my house.
The goal is to have a wood shop in one half of the main level, and a home gym on the other side with stairs leading to a small upper level that will be used as an office/studio space. Heated/cooled with minisplits, will be pretty well-insulated with a tight envelope.
The building is really a piece of junk (everything about it was very much a “homeowner special”). I’m trying to make this thing nice enough that I’ll enjoy the space, without breaking the bank.
I’m planning on using roughsawn 2x8s for the floor joists at the upper level, and would love to leave them exposed from the main level above the gym (I’m going to cover them on the woodshop side to insulate between bays). I’ve seen a few (relatively modern) cabins whose upper levels used 2×6 pine tongue-and-groove boards as both the subfloor and finish floor. I’d like to glue and screw them in place, probably 2 screws through the face over each joist. I’ll peg and sand the holes after. Leaning towards a tung oil finish, but not sure if I should pre-finish each board before install, then put down a few more layers of tung oil once install is finished.
Any thoughts / feedback / critiques are welcome. Thanks everyone!
Replies
Not uncommon to use it as both but, dirt will eventually filter through as it shrinks and leave a film on the downstairs. Don't do it over a living area would be my advice
Thanks Florida. Not sure what you mean by 'dirt filtering down'? I could see some dirt & grit getting between the boards as they move, but wouldn't the tongues just catch anything before it moved down to the lower level? Unless they were moving so much that the tongues were disengaging from the grooves - but at that point, I think I'd have more serious problems.
No, the dust will come right through the boards. It won't happen overnight but eventually, it's going to come through.
Its a personal taste thing. I like the look of tung oil finished pine. I'm sure that you know the wood will be soft and it'll look beautiful initially and gradually it'll get beaten up scratched and dented.
I would embrace that look and move on.
If the areas above and below are going to have conditioned air then you you are all set. If not then coat all six sides with at least one layer of tung.
Thanks Sawdust_Steve. Spot on, I am totally into the old / beaten up / distressed look of old pine floors.
The spaces above and below will be conditioned. It actually hadn't occurred to me to not treat the pine subfloor/finish floor at all, though I suppose that might help it get beat up faster. I think I'll probably lean towards the tung oil route anyway; I like the look, and it's easy enough to reapply down the road (without any sanding - that's definitely a selling point for me).
You definitely still want oil on the walking surface. If its conditioned you can skip coating all six sides
I installed random width 2by t&g flooring on the second floor of my hybrid timber frame last November. (Im still working on the house and it hasn’t seen a winter of heating in Massachusetts yet). Most of its 8” and 6” wide and I hand banged vinyl coated sinkers (10 penny 3” I think??) with the occasional 3” decking screw if it needed more persuasion. The local mill that turned my air dried pine in to this flooring does a nice job and it went together really tight. Basically just treated it like any other t and g flooring and if I had a flooring stapler that I thought would hold I would’ve been fine using that. One of those big long nail punches was nice to have as well. I left a heavy 3/8” gap east and west for expansion- baseboard will cover. I did a pretty good job keeping the timber floor joists all in same plane but you (I) can see the shadow where I didn’t get it perfect. Sounds like that might not bother you. Good luck
Thanks for the reply, levinw, that's all great beta. I'm out in Montana where it's super dry (especially this summer...), but am from Massachusetts originally, and I can confirm: the lack of humidity out here definitely lets you get away with some things that wouldn't fly back east. That said, still planning on leaving generous space around the borders for expansion.
I'm curious about the air-dried pine you brought to your local mill - was that pine planks that you had purchased and just needed them kiln-dried and milled to have t&g edges? Or was it lumber you harvested yourself? I do need to take down a huge pine tree outside my house, but I think the extra work and expense of milling it up for flooring might be more than I can handle.
Any thoughts on using something like subfloor adhesive on top of the joists (carefully-applied so it doesn't smush out) and under the flooring? Might be overkill, but I'm thinking it might also reduce squeaks.
I had most of the house logged and milled on site- it was some nice pine that was where we built the driveway. So two birds one stone. At the time I figured the cost of paying for that work plus all of my thinking would break even, but with lumber prices spiking it worked out GREAT overall. By the time I took it to the flooring/mill it was somewhat air dried. They kilned and t and g Ed it.
All in all, yes a lot of leg work and nothing wrong in just buying something nice.
Mine had some squeaky spots, but I could have done a better job flattening the top of the timber joists they sit on. I’m not big on using PL with wood- makes sense with advantech and other composites. If your going this route I think you gotta except a certain amount of “imperfections”