Got any plate glass windows or a mirror big enough to check?
Use something 'known flat' to measure the deviation in the floor? Good idea. Will have a think. I have a very large glass tabletop desk but it weighs a tonne and all my stuff is on it...but I'm sure there's other stuff we could use.
Use something 'known flat' to measure the deviation in the floor? Good idea. Will have a think. I have a very large glass tabletop desk but it weighs a tonne and all my stuff is on it...but I'm sure there's other stuff we could use.