Re: Rescued limestone from the skip, advice on whether to seal the bac
Trying to make them square will be a maul IMO. Can't you just buy some cheap 6x6 and stick a cheap border in there to liven it up?
You'll need to find which edges are not square for each
tile as some may be a parallelogram. Which means measuring the
tile from corner to corner diagonally to find the shorter measurement. Then you're cutting each
tile down to it's smaller size. Which might be a different size for each
tile as some might be more out than others.
If you set up just say 590 on a table saw and cut both ways, you may still end up with a parallelogram, just smaller. So you'd still have the problem just now with smaller tiles.
Try measuring a few from corner to corner diagonally and see if they do seem to be shaped like in the picture.