I live in Rhode Island. I put down about 600 sq. ft. of 9" wide (3/4" thick, plowed out on the back, 8' to 14' lengths) T&G southern yellow pine planks last summer when it was very humid. I initially installed them with flooring staples through the tongues (about every 1' or so) and then went back and face screwed them down, 2 screws across the width every 32" along the length(and covered the screws with plugs).

Now that it's winter and drier the planks have shrunk a bit and there is about a 1/8 gap between boards.

My question => is it ok to install more planks the same way now that it is winter (I have about 2000 more sq. ft. left to do)? I am worried that if I install them with essentially no gap now, in the summer the boards will try to expand but will have nowhere to go and might warp or cup.

Thanks for any info... Jeff
(sorry if I already posted this)

You are mostly correct in your thinking. It really depends on the moisture content of the new floor vs your subfloor. If its been sitting in the house this whole time its acclimated to a dry state. Installing a floor "tight" that has been acclimated to a dry state is a sure fire recipe for a badly cupped floor. In this case you can do one or two things. 1. build some expasion space into the floor by using pennies/washers/weed eater line ect. 2. wait till late spring to install.

I live in Massachusetts and wanted to start my hardwood flooring installation last winter so I put a humidifier in the room with the flooring spread out on the subfloor. I got a moisture meter and periodically checked the flooring to see if the moisture content had increased to the correct %. It took several weeks to acclimate and it's been fine. I have central a/c, whole house humidifier, dehumidifier in the basement, and also keep a humistat in the house to make sure the humidity level is correct for the floors at all times.