Advice on leveling a plank floor
Can you all help with some advice on this? I need to lay down subflooring in a 30′ X 40′ loft conversion. The existing floor is 2X6 or 8’s with some cupage and checks faced nailed with #8 commons. To get a flat level floor should I:
1.) Tear up all the floorboards and put down Ã‚¾” T&G plywood.
2.) Tear up all the old floorboards. Plane to remove cups and relay. Cover with Ã‚¾” T&G.
3.) Some other way that isn’t as much work!
Thanks in advance for the elegant solution.
you sghould be able to get away with t&g plywood, glued and screwed. As far as level is concerned if the floor is way out you can builld a very thin strapping floor that's built up to level, make sure the plywood boards are staggered and the joints are supported and edge glued.
Can you explain a "very thin strapping floor"? All my experience is in new construction this remodel is making my head hurt. Thanks, Vic
Vic, is the floor level and the boards cupped? If so than countersink the nails and rent a floor sander to remove the cupping. Go corner to corner (dia.) across the floor.Then put your T&G ply over with glue & screws. Good Luck Bill D. of QWC
Yes, the boards are cupped, some lifted and I have holes to fill where ductwork was brought through but the floor is level. Joists are huge, real 4 X 10's. This was the hay loft in an 1830's livery that was converted to a restraunt and we're now converting to an apartment and store. Vic
Vic, If this is an 1830's loft with real 4x10's then I'll assume the boards are possibly real 2" pine or oak rough sawn ? I'd nail down those that are loose repair those that need it and sand it and seal it with your choice of sealers. It'll look great & unless you are concerned with stuff falling through the cracks you shouldn't need the T&G ply. I do alot of old house restoration and sometimes the older lumber has beautiful grain.We're currently work to restore an 1724 brick and frame manor house. Again good luck! Bill D. QWC
Bill, I wish I could do that as they are nicely grained pine but there are wide gaps between boards. The timber framing on this place is awesome. Vic
Welcome to my world, all my work is in remodeling/restoration in 100 + yr old buildings. Its always takes way longer than I think it should and I've been at it for awhile now.
When I suggested strapping it's like the 1x3 furring set 12" o.c. at right angle to the floor planks. Find the high point and work off that, shimming up the rest or even doubling strapping where neccessary or even use 2X if its way out. Providing the doorway is not at the lowest point (somehow it always is though) the change in floor height will be around 2 1/8" (3/4"strapping+5/8"plywood +3/4"flooring). If the stairs hallway etc need work you can hide the rise in a hallway and work your subfloor back to 0". I have also set 5/8" t&g plywd glued and nailed straight onto old cupped floorboards. Air naiiling big ol spikes every 6" and at opposing angles works as well as screws for me.
What is the degree of "unlevelness"?
What's your motivation?
What type of wood? I have done quite a few loft conversions and most of the time the older ones have maple flooring. It is so much harder to sand than oak. Major factor in your equation.
If your concern is just cupage...
1) ...and the floor is in solid condition, why not sand it down? Those old planks can take it. You won't get rid of all the blemishes but that is character.
2) ... I mean deep cupage - you can lay a new floor over it, perpendicular to how it is now. Or you can lay down 1/2" plywood with lots of adhesive and screws (40/sheet) and lay down the new wood flooring using extra long cleats/ flooring nails.
If the floor level is all over the place and dead level is very important to you, rip up the existing floor down to the joists. I find it hard to believe you have 2x6's or even 2x8's. (Probably 3x's.) If so this might be the reason for the undulation. Regardless, you must then sister 2x6's to the joists to form a level structure. You might be able too get away with 2x4's in some spots. Next, install 3/4 plywood and the 3/4 wood flooring. Don't even think of reusing the old stuff inless you have no day job, hate vacations, and thrive on disappointment.
Tip: Be sure to establish the high and low points before you begin. Do not use a 6' level to do this. You need a laser or site level. Don't bite off more than you can chew. Do it in phases. This is alot of back breaking work. Think dumpster volume and weight. Whatever you carry out you will have to carry in. You may, for a fee, be able to boom truck the debris out on the same day you boom truck the new material in.