For lab testing of tiles in India, use a laboratory accredited by NABL, the National Accreditation Board for Testing and Calibration Laboratories, and check that the tests you need are on its accreditation scope. NABL accredits laboratories against ISO/IEC 17025, the international standard for testing laboratory competence.
Accreditation does not guarantee that a tile is good. It tells you the lab is competent to run specific tests, and the report tells you what the tile did.
What does NABL accreditation mean?
NABL is India's accreditation body for testing laboratories. A lab can be accredited for some tests and not others, so ask for its certificate and read the scope. The scope lists the test methods covered. A lab accredited for chemical analysis may not be accredited for tile breaking strength.
Check the certificate's validity date, and confirm the details on the accreditation body's own website where you can. A copy of a certificate alone proves little.
Which tests should you commission?
Tile tests follow the ISO 10545 series. Choose the tests that match your product and market:
- Water absorption, which defines the tile body and the tariff line.
- Breaking strength and modulus of rupture, for load-bearing performance.
- Dimensions and surface quality, including warpage and edge straightness.
- Resistance to surface abrasion for glazed floor tiles, and slip resistance where your market requires it.
- Frost resistance for tiles used outdoors in cold climates.
The tests worth ordering before shipment are listed in tests to order for tiles before shipment.
How do you commission a test properly?
Who takes the sample is as important as who tests it. A sample sent by the factory tests the factory's best tiles, not the shipment. Have the sample drawn at random from the finished lot, sealed, labelled and sent to the lab with a record of the lot, design and batch.
Pay the lab yourself, or through an agent working for you, and receive the report directly. Instruct the lab to report to you, not only to the factory. The testing fee is quoted by the lab, so ask for it in advance.
How do you read the report?
Look at the details before the results. Check these points first:
- The lab name, accreditation number and date of issue.
- The sample description, which should match your design, batch and lot.
- The test method and standard, including the edition.
- Whether the results meet the limits in your specification, and not only the lab's own.
- Whether the report shows an accreditation mark on the tests, since results outside the scope may not carry it.
Our guide on reading a lab certificate covers the checks in more detail.
How often should you test?
Test before the first order is approved, then again on a sample of each later lot. Tiles can change when a factory changes raw materials, glaze or firing, even if the design code stays the same. Keep each report on file with the lot number, so that if a complaint arises you can show what the tiles did when they left the plant.
How we help
We draw samples from the finished lot, have them tested and review the report against your specification. To plan testing for an order, book a free sourcing review.