To gap or not to gap
I'm about to install a random width (3-4-5"), 3/4" thick quatersawn sycamore floor in an old farmhouse kitchen. My question that I've been debating for a while is whether or not to leave small gaps (1/64 or 1/32 at most) between the planks as I install it. It will be blind nailed with corrogated flooring nails.
Floor construction is tongue and groove 1" boards over joists, covered by luan, and topped with linoleum - I plan to leave the linoleum in place as a vapor barrier/cushion.
It's january, very dry now, the new floor is acclimated, and moisture of both it and the subfloor are about 8%
Reasons I might gap the planks . . . .
There is no cental heating/cooling system, the baseboard radiators result in the house being quite dry all winter. The windows are open all summer, so the humidity rises greatly. I know the planks will expand, and I'd much rather have small even gaps in the winter versus a bucking problem or repairs later on.
Reasons not to gap . . . .
It is quartersawn flooring, so it will be somewhat more stable.
It will have large expansion gaps around the perimeter covered by moulding - the kitchen is about 14 feet wide across the grain of the floor, so maybe that would be enough.
Thanks for sticking with the long winded question, I'd be eager to hear any thoughts.
Re: To gap or not to gap
I'd go with the 1/32 gap and then put a few coats of good sealer over the top of the wood. Since it's qtr sawn, you've got good stuff and the movement won't be so severe. It's going to move, most likely, no matter what you do (with no A/C) but with no gap, you could get some buckling and I know you don't want to deal with that. I'd rather see really tiny cracks and if you put enough sealer, it may fill those to some degree.