Hello again
Well, I got the top man from the tiling firm around to look at my ceramic floor and to ask him to rip it up and relay it. Not surprisingly he went to great lengths to persuade me that the job is acceptable and the bottom line is that he wants me to pay the cost of removing and relaying the floor. I also spoke to our local Trading Standards office who were amazingly helpful - I must be over-cynical about these things. Basically, TS say that the floor has to be laid "to our liking" subject to any reasonable constraints - you can't insist on a square circle. If a compromise or any choices have to be made then the onus is on the trader to consult with the customer before proceding.
Anyway, the reason for posting is to ask about spirit levels. One of the tricks that the tiler tried was to go downstairs and measure the levelness of the ceiling below the bathroom floor. He argued that this would be parallel to the underlying floor since both were nailed to the same joists. To measure the ceiling he took my spirit level and applied the flat face opposite the phial/vial to the ceiling and voila, the bubble was way off centre thus proving that the joists were far from level. The fault was clearly with the joists. This almost fooled me until I realised that my spirit level has a curved tube which can only be used in the correct orientation - using it upside down will inevitably cause the bubble to go to one end or the other. I pointed this out and the guy backed off saying that he wasn't sure which type of spirit level I had but his could be used either way up.
So, can some spirit levels be used upside down or is this just more bulls**t
Thanks Jeff