Yeah, the "middle of the room buckle" is the worst. Logan849 is totally right about the tape measure. I learned that the hard way when I eyeballed it and ended up with a seam that looked like a speed bump in a living room. Had to pull everything up and start over. Now I'm the slowest tack strip installer on the planet, checking every gap three times. That one rush job cost me more time than ten careful ones.

So wait, are you warming it in the oven first, or just keeping it way closer to the forge?