Your help please on laying out polished limestone

[BLOWKY]

Looking for a little assistance in laying out some 610 x 406 polished limestone. The room is exactly 2.5MTRS wide, now I have the option of putting down 4 tiles (2455mm with 3mm grout and two slithers 23mm each eather side to make up the 2.5mtr, or have the 4 tiles and a 46mm slip one side (sure this will look odd), or 3 full tiles plus a 305 wide tile (half a 610) one side and a 365 wide tile the other side (lot of waste), or and this is the last option, use the 4 full tiles and build out the wall one side once the tiles are down to meet the edge of the tiles, this is not to much of a problem as it's a chalet bungalow and this is a 1mtr high eaves wall, I would probably trim back the width of the oposite tile to 295mm as this goes up the wall full height both ends of the room, this way slight reduction wont be noticed and it will allow me a little lea way if the wall is out of true. By the way I am an Engineer not a Tiler, I work to thous not inches, it will take me a long time! One more question for now, I have glued screwed & sealed 6mm backer board on to 22mm chipboard, the floor is flat and level, warm up loose coil heating cable will be laid this weekend and be covered by flexible SLC, my question is what size trowel castilation (you will probably call it something else) should I use. Thanks to anyone that reads and /or replies. If the above is not clear I can email or post a floor diagram.

[aflemi]

Not sure about trowel notch size sorry.
What will the tile edges finish up against, ie is there skirting on the wall there already?
If not, that would take up some extra width avoiding the slivers (sry but only snakes slither ) and could be made with either tile or traditional boards.
Also, I think you'd find the waste would not be much different either way as you'd need 1 tile to cut 2 slivers with machined edges and with larger edging tile you still have the cut portion with 1 machined edge to use somewhere else (hope that's logical).
In my view, have the larger width edge tiles unless you can stretch it out with skirting tile/board and 4mm grout line.......

[murf]

I would centre this floor and lay it in stretcher bond. what happens with the cuts
would be irevelant as long as they are equal both sides. Also i think a 2mm joint
looks much better with polished limestone. Regarding the trowel, you will end up
back buttering the tile anyway so 12 mm notch will suffice.

[garretridge]

3 full tiles and good cuts on both sides with 2mm grout lines is the only way it will look right you will have waste but slithers will ruin the look of the job and the tiles are not cheap so better to do it right first time !

[oogabooga]

No to the slivers ( that would look garbage) and agree with the others about the 2mm grout line. Use an unsanded grout too (won't scratch your polished finish like sanded).