Replacing carpet on 2nd floor with 3/4x3 inch prefinished oak hardwood. However I am not sure were to start. See link to floor plan:



Floor joists run from top to bottom and stairwell will remain carpeted.
Is it easier to start from the left or right bedroom then work your way to the hall or from the hall out to the bedrooms? I will be using a matching oak nosing piece right up to the stair so should I start from the nosing and work my way out?

Any better suggestion would be welcomed.

Since your joists run the long way of the three bedrooms, my preference would be to sheet the subfloor with 3/8" minimum CDX plywood and run the flooring the long direction in those bedroom. Then I would start off the exterior far right wall in the master and work my way across. Check periodically that you remain parallel with all walls. Install the stair nose right before you lay the flooring up to it. Square the nose with the floor. Good luck.

The top step is still going to need a stairnose. That stairnose is where I'm starting, if I were doing the job.

Gary I agree laying the floor top to bottom verses left to right would look better... but if I can get away with it I would rather not install more plywood. Floor joists are 12" on center with either 5/8" or 3/4" plywood subfloor. I don't want to get into the additional cost of laying more subfloor if not necessay. I've read hardwood should always go across the joist rather than parallel but have also read it dosen't matter what way depending on subfloor. Is there any restriction on what direction I should or should not lay the floor with this type of subfloor?

Floorguy. Just install the stairwell nosing peice and work outward no matter what direction? How do I keep the flooring square throughout the rest of the rooms? Should I place a center line somewhere and measure from there?

SDry lay rows of boards, get squarness control lines popped and install the stairnosing.

If you are going to do as Gary suggested, so you can run the floor with the joist, you won't need to install the nose, till you get to it as the flooring ends will butt into it..

If the joists are 12" OC, the subfloor maybe stiff enough and flat enough to install parallel to the joists. No way to tell from here. Double check that 12" OC. It is not common.

Main floor joists are 12" O.C. I suspect the second floor joists run the same way and are also 12" O.C. Once I lift the carpet I will be able to tell.

One problem that can occur when laying parallel to joists is the following. If the joists are solid wood joists and not trusses, they can sometimes be very uneven. I've seen 2x12's range from 11&1/2", 11&3/4", 11&5/8" 11&7/16", etc. If the floor framer was careless and did not crown the joists and pick out the ones that were all the same width, you could have a very wavy subfloor. And when laying parallel to a mess like that, it can cause major installation problems, especially with prefinished flooring. So double check that subfloor to ensure it's stiff and sound enough. And FLAT as well.

I think I will shy away from laying parallel to the joists. Although it would look better the additional cost and labor of adding more plywood subfloor is not worth it. I am doing the entire second floor, minus bathrooms, and will have to rip up carpet and move furniture around in the process. If the house was empty it would be a different story.

So I am leaning towards what Floorguy wrote and will start outward from the stair nosing peice (hall), laying planks left to right across the joists. I plan on using a guide line from the master bedroom south wall (next to master bath) extended across through the left bedroom to try and keep the floor as square as possible.

Any better suggestions or advice would be appreciated.