The defects importers find most often in floor tiles fall into three groups: dimensional faults such as warpage and size variation, surface faults such as chips, spots and print errors, and sorting faults such as mixed shades or grades in one order.
Most can be caught at the factory, before loading. A few only show once the tiles are laid. Knowing what each looks like helps you write the right acceptance rules into your order.
Dimensional defects
- Warpage: the tile is not flat, so corners or edges sit high or low and cause lippage between tiles.
- Calibre mixing: tiles of slightly different sizes in one order, which makes joints uneven.
- Out of square: the corners are not right angles, so joints open up along a row.
- Edge straightness: one edge bows slightly, which shows on rectified tiles with thin joints.
- Thickness variation: tiles of different thickness in one lot, which makes the floor uneven.
ISO 10545-2 sets the test methods for these, and EN 14411 or ISO 13006 set the limits for each size and group. Our guide on warpage and flatness explains the flatness limits.
Surface defects
- Chips on edges and corners, often from handling between kiln, sorting line and box.
- Pinholes and craters in the glaze, from gas escaping during firing.
- Spots and specks, from dust, dirt or glaze drops on the surface before firing.
- Print faults, such as missing lines, colour streaks or blurred patches, from blocked inkjet nozzles.
- Glaze crawling, where the glaze pulls back and leaves bare patches.
- Polishing faults on PGVT, such as waves, haze, scratches and unpolished patches.
- Cracks, either visible or hairline, from pressing, drying or kiln problems.
Under ISO 13006 and EN 14411, at least 95% of tiles in a lot must be free from visible defects when viewed at a set distance under the test in ISO 10545-2. That figure is the standard's floor, not a factory grade. Premium grades are usually stricter, so ask for the factory's written definition.
Sorting and packing defects
- Mixed shades in one design, which show as patches of different colour on the floor.
- Mixed grades, where Standard or Commercial tiles appear in Premium boxes.
- Wrong design or face mix, where one box holds mostly one face.
- Wrong box marks, where the shade or calibre code does not match the tiles inside.
- Short boxes, with fewer tiles than the packing list states.
- Broken tiles from weak boxes, loose pallets or poor loading.
Sorting faults are the ones importers complain about most, because they show only once the floor is laid. Our guides on shade variation and avoiding mixed grades in a shipment cover the controls.
Defects that appear later
Some problems only appear after installation. Polished tiles can stain if the surface was not sealed or nano-treated properly. Glazes can craze over time if the body and glaze do not match. Tiles that look flat in the box can show lippage on a large floor.
Many installation problems are blamed on the tile but start with the adhesive or base. Hollow spots, cracks over screed joints and tiles lifting are often installation faults. Ask for photographs and installation details before you accept a claim from a customer.
How to catch them
- Write the grade definition, shade and calibre rules into the purchase order.
- Inspect a random sample of boxes before loading, not boxes the factory chooses.
- Lay out a mock-up of several square metres to check shade, faces and flatness together.
- Have a lot tested to ISO 10545 when your market or project requires it.
- Photograph boxes, pallets and the loaded container as a record.
The full inspection method is in inspecting floor tiles before shipment.
Next step
We inspect production and loading against your written specification and report defects before you pay the balance. To set acceptance rules for your next order, book a free sourcing review.