Cutting Subfloor of basement landing to get 12ft sheets of drywall down
 

suppose your basement landing is contructed as below. I have about 3 feet of height from the middle landing to the basement ceiling. I need another foot or so to pass the 12 foot drywall through. Would it be damaging to cut out some of the subfloor from this landing? How would you fix the cut out subfloor?

Go for it---I've done worse---removed all the treads from a staircase one time to bring in a cabinet.

To rebuild the landing--sister in a 2x4 onto the joists and replace the subfloor that you removed.

Are there no windows you could take out to get the sheets in? We have vinyl windows, and I just unscrewed them...brought in my sheets, resealed and rescrewed.

unfortunately the windows in the basement are those short ones

i personally would just use 10ft or 8ft sheets and have a couple extra butts to skim out, watch you'll get that 12fter down the stairs go to put it up and SNAP! you now have 2 6fters and a nasty butt joint to mud!

it appears to me (although I could be wrong) that length is not the issue...it's the 4' width that is creating this dillemma

its a combination of both getting them to the basement