Sanitaryware is tested in two ways: how the product works, and how strong and durable the ceramic is. For a WC that means flush tests, a load test, a water absorption test and a glaze crazing test.
The exact tests and limits depend on the standard your market uses. In Europe that is EN 997 for WCs with integral trap. In North America it is ASME A112.19.2/CSA B45.1.
Flush performance tests
A WC must clear waste, rinse the bowl and refill the trap, all with a set volume of water. Standards test this with test media that stand in for waste. Typical checks include:
- Flush volume, measured to confirm the WC uses no more water than its stated rating.
- Bowl wash, often checked by drawing a line inside the bowl and seeing whether one flush removes it.
- Waste removal, using standard media such as balls, granules or paper, depending on the standard.
- Drain line carry, which checks that waste moves far enough down the pipe.
- Water seal depth after flushing, which keeps sewer gas out of the room.
- Splash, so water does not leave the bowl when flushed.
Water-efficiency programmes
Water-efficiency programmes add their own performance tests. For example, the US WaterSense programme uses a waste-removal test with a set minimum. See WaterSense and Indian WCs for details.
Load test
A load test checks that the WC or basin will not crack or fail under a person's weight. It matters most for wall-hung WCs and basins, where the fixing points carry the whole load. The standard sets the load, how it is applied and for how long. Ask for the result on the test report, not just a pass mark.
Water absorption
Vitreous china is a dense ceramic body. It is generally defined as absorbing no more than 0.5% of its dry weight in water. A body that absorbs more can stain, smell, and crack in frost.
The test cuts pieces from a fired product, boils or soaks them, and weighs them before and after. A factory lab can run it quickly, so it is a good routine check on each batch.
Glaze and surface tests
- Crazing resistance, which stresses the glaze to see whether fine cracks appear. See crazing and pinholes in sanitaryware glaze.
- Visual inspection under set lighting for pinholes, spots and glaze runs.
- Dimension checks, including trap size, outlet position and fixing holes.
- Flatness checks on mounting surfaces, covered in our article on sanitaryware warpage.
Who does the testing
A good factory runs routine tests in its own lab, often on a flush test rig on site. Certification testing should be done by an accredited third-party lab. Check that the report names the exact model, the standard and its edition, and the lab's accreditation. Our guide on reading a lab certificate explains what to look for.
Next step
We check test reports against the model you are buying and can arrange independent tests on samples or production lots. To discuss your range, book a free sourcing review.