Sounds like he might be trying to say that you won't come after him anymore for the tile and concrete being unlevel, though it's poorly written and could be interpreted more broadly so you're right to be concerned. By poorly written, I mean the way I read it, it could be seen as him not being responsible for any current or future issue regarding 1) Concrete, 2) Tile, or 3) Level Variation (in other words, concrete problems in general, tile problems in general, or level variation problems... three separate potential issues).
I think a more accurate way to write that would have been "...that may arise pertaining to any concrete or tile level variation."
--Michael