A rectified tile has its edges ground after firing, so every tile is cut to the same size with sharp, square edges. A non-rectified tile keeps the slightly rounded edge it had when it came out of the press and kiln.
Rectified tiles allow narrow grout joints and a cleaner look. Non-rectified tiles vary more in size, so they are sorted into calibres and need wider joints. Both can be good products; they suit different floors and budgets.
Why tiles need rectifying
A tile shrinks in the kiln as it vitrifies. The shrinkage is never perfectly even across a kiln or between batches, so tiles from one run differ slightly in size.
With non-rectified tiles, the factory measures tiles after firing and sorts them into size groups called calibres. Tiles within one calibre lay well together. Read what calibre means for how this works.
With rectified tiles, the factory removes the variation instead. Diamond wheels grind all four edges to one exact size and make the corners square.
How they compare
- Size: rectified tiles are very consistent. Non-rectified tiles vary between calibres and slightly within one.
- Edges: rectified edges are sharp and square. Non-rectified edges are softer and slightly rounded.
- Joints: rectified tiles can be laid with narrow joints. Non-rectified tiles need wider joints to absorb size differences.
- Look: rectified floors look closer to natural stone. Non-rectified floors look more traditional, with visible grout lines.
- Laying: rectified tiles need a flatter base and more care, because narrow joints show any lippage between tiles.
- Cost position: rectifying is an extra process step with grinding wheels, water and handling, so it adds cost.
Joint widths
Manufacturers usually recommend a minimum joint for each product, and many markets have installation standards that set their own minimums. Rectified tiles are often laid with joints of about 2 to 3 mm. Non-rectified tiles usually need wider joints. Check the factory's installation guidance and your local standard before you advise customers.
Never lay tiles with no joint at all. Tiles and the base move slightly with temperature and moisture, and a floor with no joints can lift or crack.
Which sizes are rectified
In Morbi, most large formats, such as 600x1200, 800x800 and slabs, are rectified. PGVT is usually rectified as part of polishing, as covered in PGVT vs GVT. Smaller sizes and economy ranges are more often non-rectified.
Rectifying does not fix warpage. A rectified tile can still be curved across its face, and that shows more with narrow joints. Ask for flatness results too. See floor tile warpage and flatness.
What to check
- Measure several tiles from different boxes with a calliper and compare with the work size.
- Lay four tiles together on a flat surface and check that corners meet and edges line up.
- Look for chipping along ground edges, a sign of worn wheels or poor handling.
- Confirm in the purchase order whether the tile is rectified, and for non-rectified tiles, that each design ships in one calibre.
Next step
Rectified or not is a choice to make by size, market and installer skill. We measure samples and production tiles before loading so the shipment matches your order. Book a free sourcing review to begin.