How do I cut 20mm porcelain patio slabs? A quick and simple guide to the options available.

20mm porcelain patio slabs are the latest revolution in landscaping.  They are ridiculously hard wearing and look, putting it simply, beautiful. They are easy to clean, last for years, are frostproof, so won’t crack or chip in the cold, and due to their strength can be used with a pedestal system for rapid installation.

The only downside with them though is they are difficult to cut.

Porcelain is an extremely hard material and 10mm thick interior porcelain tiles are difficult enough to cut let alone the 20mm thick exterior tiles.

There are 3 main options available when it comes to cutting 20mm porcelain slabs – manual cutting (score and snap method), dry diamond cutting (with an angle grinder) or the cleanest, but slowest way, wet diamond cutting (bridge saw).

The first option, manual cutting with a score and snap cutter, is the quickest way but you’ll find there are very few cutters on the market that will actually have the breaking power to snap a 20mm porcelain slab. It has been proven, unfortunately, that quite a few of the cutters that make the bold claim of being able to snap a 20mm porcelain slab, often actually can’t when used in the field.  With the score and snap method you’ll also always end up with a slightly jagged edge below the scored line which is due to the tile breaking and following small fissures and cracks in the tile which often aren’t visible to the naked eye.

Dry diamond cutting with an angle grinder is a popular option as there are some very good diamond blades on the market that can cut 20mm porcelain slabs quickly and effectively when fitted to an angle grinder. It’s relatively quick but can be fairly inaccurate if care is not taken when controlling the direction of the grinder.  The cut’s can often ‘wander’ a little leaving not such a clean, straight edge.  A lot of dangerous silica dust will also be generated by this method and we’d recommend using some kind of dust suppression system to prevent this.  Alternatively, a petrol disc cutter can be used which has an in built water feed but these are more difficult to control and may create an even more inaccurate cut.

The third option is wet diamond cutting with a bridge tile saw.  This is the slowest option but will give you a superior finish to the cut edge of the slab.  The slab is placed on the bed of the saw and pushed up against the back fence, then the saw is pulled slowly through the slab allowing the diamond blade to cut cleanly and accurately whilst being fed with a steady stream of water.  Bridge saws are also bulky, expensive machines so they are often hired by contractors on a job by job basis rather than purchased and stored.

So, in summary, the quickest ways are with a manual score and snap cutter (if you can find one that will do the job) or an angle grinder.  Both options will leave you with a clean enough cut but not perfect if done properly.  The option to get the best cut is with an overhead bridge tile saw but this can be time consuming and expensive.