You should start by learning everything you can about the porcelain you plan to use. Is it glazed or unglazed? There are different degrees of hardness — and different break strengths — to take into consideration. For quality installations, cutting is critical. Good quality porcelain does not like being cut with cheap, nasty, inappropriate blades. Only a specialist, the continuous-rim porcelain-cutting blade will do.

The more you know about your tile, the better you can choose the right tools to cut it.

Blades:

Abrasive or cheaper diamond blades will very often chip, spall, and/or shatter the tile/flag as it is being cut, resulting in unsightly, unprofessional cuts edges, or excessive wastage as damaged and broken tiles/flags have to be thrown away.

Continuous rim blades are very noticeably not divided into segments although they may have small, narrow cooling slits that sub-divide the blade. This arrangement ensures the ‘shock’ caused by the blade as it chews its way through the substrate is minimized and there are none of the hammer effects that can affect when heavily segmented blades are used, with each individual segment imposing a repeated percussive strike as the blade spins around at high speed.

The Right Tools: Bench Saws

For the very best quality work, a bench saw should be used, as these ensure the tile/flag is held safely and securely in position during the cut, that the blade is properly cooled and washed with water while cutting, and the accuracy of cut is as near perfect as possible.
Hand-held cut-off saws have a gyroscopic effect due to the high-speed spinning of that large blade, and while this tends to ‘steady’ the saw when in use, it can make it extremely difficult to keep the cut perfectly straight, as even the slightest twitch or tic or tremor is exaggerated by that same gyroscopic effect. The result is a cut line that, even with the best will in the world and years of experience, can look a little ragged.

Finishing with Quality:

As ever, the key advice is to measure twice and cut once. Take your time, keep the blade true and straight, and use water to both suppress the dust and keep the blade cool.

On completion of the cut, the sawn edge and the arris should be ‘sanded’ down, using specialist diamond polishing pads of various grades, starting with a coarser grade and finishing with the finest.