Help with long boards
I am in the process of installing unfinished 3.25” white oak hardwood flooring. I am currently dry fitting some of the floor together to make sure my starting line is true to the wall. The starting line boards are the only pieces currently tacked down with 15g nails. All other pieces are floating atm. What I have noticed is that my longer pieces which is of course the more desirable ones are often curved on the flat (as seen in my pic notated by the arrow) and cause larger gaps in the middle and sometimes wavy up and down but that easier to fix. When actually installing these longer planks does one usually just apply pressure to the bend to get it to straighten out as best as possible and then nail down or is there a trick, or are these boards SOL? Any help is appreciated.
Please note that my starting line was measured 4” from the sill plate at each end of the room and then used a laser level to lay the first line. The laser laid right on the 90degree start of the tongue. All boards will have .75” of room to expand under the dry wall. I wanted to avoid having to use qtr round.