So I have a 3 bedroom house, middle room being the smallest. The master is the widest covering the width of the house, and the 3rd room at the back is long and 2/3 the width of the master.
I am doing the install one room at a time as there's stuff I have to move around to make room. Currently I occupy the master with furniture etc.
I would like to set up long runs of wood that span the length of the house, going from master all the way to the back end of the 3rd bedroom. I'm also going to run a piece of flooring centered across the bottom of the door to break up the rooms and divide the floor, but keeping the long run. The middle room steps out into the middle of the hall. offset right and across the door is the bathroom, offset left is the stairs down.
So here is the issue I'm attempting to plan around. I'm trying to get the runs parallel to the hallway so it's straight. It also has to be parallel to the door opening to the middle room, this might turn my install a few degrees in the room, which is fine. What I'm having trouble with is carrying the run into the master and into the 3rd bedroom. I've pushed out a parallel guideline into the hallway from the middle room transition, using this as an anchor as best I can that will be parallel to the door when it's closed. This guideline seems to match the nose for the stairs. It extends into the master where the entrance steps into the right side of the room. From my line to the right wall I have maybe 1/2 inch out of square for a room that's about 12 feet wide. measuring the left wall corners off my guide, I find I'm only about 1/4 inch off from one corner to the other off the far left wall. That's very tolerable, though could be better, but it's a 30 year old house, I expect rooms not to be square. They aren't. So I'm very willing to take 1/2 out.
Here's where things go south. Using my laser square, I project the guideline into the 3rd bedroom. To one wall, I believe I might be 1/2 out. Which is not bad, but I can also hide it since the closets are on that side and I can hide that under the sliding door tracks. Where I will make the transition into the closets.
The problem is the other wall, over 11 ft it's almost a whole inch off.
My boards are 3 1/4" wide, and 1 inch over a run of 11 ft is going to be very noticeable. I won't be able to hide that under molding, in fact the shoe mold might make it look worse.
Should I run with this and chalk it up to the house not being square, or is there a better way to approach this measurement? I'm thinking I could put a screw into the sub floor of the master and run a string all the way to the back of the house and try and measure perfect square from that, but I might run into an issue where the transition on the middle room will no longer be straight across the door frame.