If you’ve ever tried cutting outdoor porcelain tiles with an angle grinder, you’ll know it looks simple… right up until the moment the tile cracks. This is one of the most common frustrations DIYers face.
The truth is, most breakages aren’t caused by “bad tiles” – they’re caused by technique. With porcelain being dense, tough and unforgiving, the smallest details in your cutting method can make a huge difference.
While a bench or wet saw is usually the preferred tool for precision tile cutting, an angle grinder is still essential for cuts a saw can’t make – such as curved cuts, notches, or tricky angles. The key is learning to control it properly.
Below is a step-by-step guide to cutting outdoor porcelain tiles with an angle grinder, safely and accurately, without ruining half your slabs.
What You’ll Need
- Angle grinder (preferably 115mm or 125mm)
- Diamond blade suitable for porcelain
- Tape measure
- Chalk or pencil
- Clamps
- Plywood (optional but recommended)
- Sturdy surface or pallet
- PPE (dust mask, goggles, gloves, ear protection)
Step 1: Measure and Mark Your Cut
Start by marking your cut line clearly using a tape measure and chalk/pencil.
For straight cuts, clamping a strip of plywood along the line can act as a guide and helps stop the grinder wandering off track. It also adds stability, which is crucial with porcelain.
Step 2: Support the Tile Properly
Porcelain tiles must be fully supported to avoid unnecessary flex or vibration.
Set the tile on a pallet or flat, solid surface so the entire slab is supported—this alone prevents many cracks before they happen.
Step 3: Score the Surface
Before going in for a full cut, lightly score along your marked line.
Keep the grinder steady and level. If you’re removing a slim strip, place a little extra pressure on the tile to keep it stable and reduce vibration.
This first score line gives your blade a “track” to follow and massively improves accuracy.
Step 4: Create Tension Relief Cuts (A Must-Do!)
This is the step most DIYers skip—yet it’s one of the most important.
Cut 50–70mm in from each end of the slab, all the way through the tile’s thickness.
These tension relief cuts stop stress from building up as you cut, which is one of the main reasons porcelain slabs crack unexpectedly.
Keep pressure applied to keep the tile steady.
Step 5: Cut Along the Score Line
Now you can begin cutting through the tile properly.
- Hold the grinder firmly with both hands.
- Follow the scored line slowly and let the blade do the work.
- Don’t force the blade down – pushing too hard increases heat and vibration.
It’s normal for dust to build up around the blade, so ensure you’re wearing the correct PPE.
Step 6: Allow for Cooling Breaks
By the third pass, both the blade and the tile will start to heat up. Overheating leads to warping, chipping or cracking.
Stop for a few minutes and let everything cool before continuing.
A cooled blade will cut smoother, straighter, and far more safely.
Step 7: Adjust Your Body Position If Needed
For longer cuts, don’t overstretch trying to reach the end.
If needed, stop halfway, reposition yourself, and continue the cut with full control. Overreaching can cause the grinder to drift sideways or snag—both of which can ruin the tile instantly.
Step 8: Clean Up the Final Pass
Once the main cut is complete, go back over any areas that need a touch more depth.
This will give you a clean, professional finish.
Final Tips for Cutting Porcelain Tiles with an Angle Grinder
- Always use a high-quality porcelain-rated blade.
- Take your time—slow, steady passes win every time.
- Keep everything supported and as vibration-free as possible.
- Never skip the tension relief cuts!
- Let the blade cool to avoid unnecessary damage.
With the right technique, an angle grinder becomes a powerful tool for making cuts that a bench saw simply can’t achieve.