I also have finished a floor a week ago with 600 x 300 porc, i used self leveling compound and thought i messed up as some off the tiles were lipping, took me longer than expected to sort it, now i know the reason why.
My tiler did warn me that brickbond had a tendency to kick out but mainly due to the preperation of the wall behind. I didnt realise 600x300 porcelain was prone to kicking out due to a problem in the mfr.
The ones I've got were all perfectly flat stacked together in packs of three. Wouldnt bowed tiles have been noticed when stacking up? Or am I naive?
The tiles I used that caused the problem had such a small deflection all from the same box that it was only noticeable afterwards when I got a level the same size of the tile and rocked it from end to end.
Although it is only a small deflection from end to end it is noticeable once the tiles are down and grouted, especially not helped as they are tight joints(2mm) so all the imperfections really showed.
The only way I would have noticed is to have checked it beforehand in this manner which I now realise was my big mistake! I certainly will in the future.
This IMO is a production fault and lack of quality assurance on the manufactures part, unfortunately they will not accept liability once the tiles are fixed. (States it on every box) That's ok play by there rules next time and fault the tiles before you fix them then watch the tile shop run for cover, let them earn there coin, I get sick to death of seeing this problem week in week out and the only way to get around it is to get the tile shop to keep sending out tiles UNTIL THEY GET IT RIGHT!!!!
I recently done 200m2 of 600x300 porcelain and before I even started I faulted 125m2 with the same issues needless to say the tile shop was not happy with me, but as I kept saying "Stop selling the public S*** that you buy for $5 bucks a meter and then charge the client $45m2 If that ain't enough FAT on your C*** product for me to whinged a bit about a diserning client that commands perfection You'll keep replacing them until I say STOP!!"
The trouble is the tolerance that is allowed is i think 5% but i must say the cheaper the tile the worse it is try to stick to italian porc chinese porc is rubbish :mad2: