How ceramic sanitaryware is made
Toilets and basins are made of vitreous china: a liquid clay slip is cast into plaster or pressure-casting moulds, the hollow piece is taken out, trimmed and dried, then glazed and fired once at high temperature. A WC pan is a complex hollow shape with an internal trapway and rim channel that nobody sees after firing.
That is why sanitaryware fails differently from tiles or tableware. The piece shrinks in drying and firing, and uneven shrinkage leaves fire cracks, often inside the trapway or under the rim, and warps the foot or the cistern seat. Sizes move with shrinkage too, so fixing holes and outlets can drift from the drawing.
Morbi, in Gujarat, is the Town of Export Excellence for ceramic tiles and sanitaryware. The Uttar Pradesh ODOP page for Bulandshahr district (Khurja) also lists sanitaryware among its ceramic products. TradeStat shows US$177.92 million of ceramic sanitaryware exports (HS 6910) in FY2025-26 (provisional). Cisterns are often fitted with valves bought in from other suppliers, so the inspection covers two supply chains at once.
What we check on sanitaryware
| Check | How it is checked | What fails |
|---|---|---|
| Fire cracks | Piece tapped all over; ink or water applied to rims, trapway entry, outlet and foot, then wiped | Ink line that stays in a crack; dull note when tapped |
| Rough-in and outlet | Distance from wall to outlet centre, outlet type (floor or wall, S or P trap) and outlet diameter measured | Outlet position outside tolerance for the market (for example a US 12 in rough-in) |
| Fixing holes | Positions and sizes checked with the fitting template, bolts and the matching cistern or seat | Seat, cistern or wall-hung frame bolts do not fit |
| Foot and rim flatness | Pan or basin placed on a flat table; rocking and gaps checked; cistern seat checked | Rocks on the floor, cistern gap that leaks at the seal |
| Glaze coverage | Bowl, rim and visible trapway viewed with a lamp | Bare or thin glaze where waste will stick; glaze drips in the rim channel |
| Flush function | Flush test on the factory rig with the specified cistern and valve: rim wash, test media cleared, trap seal refilled | Dry spots in the bowl, media left behind, poor refill |
| Flush volume | Full and reduced flush measured into a container | Volume above the declared value or the WaterSense or WELS rating |
| Cistern and fittings | Cistern filled and left to stand; valve, overflow and push button operated | Leaks at bolts or valve, overflow not working, sticking button |
| Basin overflow and tap holes | Overflow channel flushed with water; tap-hole size and position measured | Blocked overflow, tap hole off-centre or wrong size |
Common ceramic sanitaryware defects and how they are classed
| Defect | Typical cause | Class |
|---|---|---|
| Crack in a wall-hung pan or basin near the fixing points | Drying or firing stress | Critical: can fail under load |
| Fire crack in the trapway or under the rim | Uneven shrinkage | Critical or major, as the buyer sets |
| Pan or basin rocks on a flat surface | Warped foot | Major |
| Fixing holes do not match the template | Shrinkage, wrong mould | Major |
| Fails rim wash or bulk removal on the rig | Rim channel blocked by glaze, wrong valve setting | Major |
| Glaze pinholes, specks or crawling on visible faces | Dust, glaze application | Minor or major by size and place |
Your defect list decides the final class.
Market rules for sanitaryware
- EU. EN 997 covers WC pans and suites with an integral trap and EN 14688 covers wash basins; these harmonised standards bring CE marking and a declaration of performance. See UKCA and CE marking for how Great Britain treats construction products.
- UK. Water fittings must meet the Water Supply (Water Fittings) Regulations 1999 in England and Wales. Approval schemes such as WRAS are the usual evidence; buyers often ask for it on cisterns and valves.
- US and Canada. ASME A112.19.2/CSA B45.1 covers ceramic plumbing fixtures. EPA WaterSense labels toilets that use 1.28 gallons or less per flush and pass performance testing, verified by independent third-party certification.
- Australia. Toilets must be WELS-registered and show the water rating label before supply; WaterMark certification is needed before a toilet can be registered.
- Gulf. Saudi building-material rules include sanitaryware; see SASO and SABER.
The inspector checks that the model, cistern and valve being shipped are the ones on the certificate and that labels match. A certified pan paired with a different valve may not flush the same way.
Packing, loading and your purchase order
Each piece should travel in its own carton with corner and base inserts; nothing should be packed loose inside the bowl unless the protection is designed for it. Cisterns with valves fitted need the valve held against movement. Heavy cartons are checked for stacking strength and stacking marks. Seats and fittings packed separately are counted against the pans.
- Model drawing with rough-in, outlet type and fixing positions; matching seat, cistern and frame.
- Valve and flush mechanism supplier, flush volumes and the certificate number.
- Glaze colour and finish, and the approved sample.
- Crack test method and acceptance (for example no ink-visible crack anywhere).
- Labels: water rating, origin, model and batch.
For ceramic soap dishes, tumblers and other accessories, see ceramic bathroom accessories.
Sources
- DGFT: Appendix 1B, Towns of Export Excellence (Morbi)
- ODOP Uttar Pradesh: Bulandshahr ceramic products (sanitaryware listed)
- US EPA WaterSense: residential toilets
- Australian Government WELS: how to register a product (WaterMark needed for toilets)
- Department of Commerce: TradeStat commodity-wise exports (FY2025-26, provisional)