Re: Flooring over Concrete Slab
You can snap a few chalk lines to determine how square and straight your walls are. If they are severely out of whack, then you'll need to work from a chalk line and cut in your edge pieces.
Most of the time you can work directly off the wall. You use spacers along the wall to maintain the recommended gap while you build out the rest of the flooring. Once it's all down, remove the shims and install your baseboards or base shoe over the gap.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!