Cutting 20 mm outdoor porcelain tiles is one of the most challenging stages of installing a porcelain patio. While outdoor porcelain paving is valued for its durability, frost resistance, and clean appearance, those same qualities make it significantly harder than natural stone to cut correctly.
Porcelain is fired at extremely high temperatures, creating a dense, glass-hard material with very low water absorption. This means standard DIY tile cutters and basic stone blades are not suitable. Without the right tools and technique, tiles are likely to chip, crack, or shatter.
The Golden Rule When Cutting Porcelain
Twenty millimetre porcelain must always be cut using a diamond blade designed specifically for porcelain and a water-cooled cutting system. Water cooling is not optional. It controls heat, reduces vibration, and prevents surface chipping and structural failure.
Dry cutting or using incorrect blades is the most common cause of wasted tiles and poor edge quality.
Essential Tools for Cutting 20mm Porcelain Tiles
- Electric wet saw or bridge saw for straight, accurate cuts
- High-powered angle grinder for curved cuts or detailed shaping
- Continuous rim diamond blade rated for porcelain tiles
- Water feed or integrated cooling system to control heat
- Eye protection, ear defenders, and dust protection for safety
Segmented or general-purpose blades should be avoided, as they create excessive vibration and lead to chipping along the tile surface.
Step-by-Step Method for Clean, Professional Cuts
Begin by carefully measuring and marking the tile using a permanent marker or wax pencil. Ordinary pencils tend to wash away once water cooling is applied. Double-check all measurements before cutting, as porcelain offers little margin for error.
To reduce chipping at the end of the cut, make a short pre-cut at the exit edge of the tile. This small relief cut helps prevent the blade from tearing the surface as it exits the porcelain.
Cut the tile slowly and steadily, allowing the blade to do the work. Excessive pressure generates heat and vibration, increasing the risk of cracks. If sparks appear, this indicates insufficient water or excessive cutting speed.
Once cut, lightly dress the edge using a diamond hand pad. This removes micro-chipping, softens sharp edges, and produces a finish that closely matches factory-cut edges.
Common Problems and How to Avoid Them
- Surface chipping caused by incorrect blades or lack of water cooling
- Cracking during cutting due to uneven support beneath the tile
- Blade wandering caused by a glazed or worn diamond blade
- Overheating from cutting too quickly or dry cutting
Ensuring the tile is fully supported on a flat, vibration-free surface is just as important as the blade itself. Unsupported areas allow flexing, which can lead to sudden cracking.
Why Correct Cutting Matters for Outdoor Porcelain
Clean, accurate cuts are essential for professional-looking joints, consistent spacing, and long-term performance. Poorly cut edges can compromise jointing, weaken edge support, and detract from the overall finish of a porcelain patio.
When installed and cut correctly, 20 mm porcelain paving slabs deliver exceptional longevity, minimal maintenance, and a refined appearance that performs reliably in UK weather conditions.
Final Advice
Cutting 20 mm porcelain outdoor tiles is not a shortcut job. The correct tools, controlled cutting speed, and attention to detail are essential. For larger projects, many professionals choose to pre-plan cuts carefully to minimise waste and ensure consistency across the installation.
With the right approach, porcelain tiles can be cut cleanly and accurately, allowing you to achieve a high-quality outdoor finish that matches the performance and appearance porcelain paving is known for.
