Production quality control
Partner factories run their own quality control during production, sorting and packing.
Standard practice
Quality & packaging
Quality you can check. Packing you can plan.
What gets checked, how samples are approved, how we check every order before loading and which packing details are confirmed for each product. We agree these points with you up front, so there are fewer surprises when the container is opened.
01What gets checked
The properties that decide how tiles install
Each product has its own tolerances and test values. These are the points worth agreeing before an order — and checking on samples and before loading.
-
Calibre (size)
Small size differences between tiles of the same nominal format. Tiles are sorted into calibre groups.
Ask forThe calibre code on each carton, and one calibre per product where possible.
-
Shade
Colour and print variation between production batches — normal for glazed and printed tiles.
Ask forShade codes on cartons, and enough from one batch for each project or area.
-
Flatness & warpage
How flat the tile is across its face and edges. This matters most for large formats and tight joints.
Ask forThe manufacturer’s stated tolerance, and a check on samples laid side by side.
-
Thickness
Nominal thickness and its consistency, which affects strength, weight and installation height.
Ask forThickness on the technical sheet, measured on samples.
-
Surface quality
Visible defects such as pinholes, glaze faults, chips or print issues, viewed from standing height.
Ask forThe visual quality grade, and photos of packed goods before loading.
-
Water absorption class
How porous the tile body is. It defines the group a tile belongs to and its likely uses.
Ask forThe test report showing the measured value and group.
-
Slip rating — where relevant
Slip resistance for floors, ramps, wet areas and outdoor use. Requirements depend on your market and the area of use.
Ask forThe slip test result for the exact product and finish, by the method your market uses.
-
Edges & rectification
Rectified tiles are ground to precise edges for narrow joints; non-rectified tiles have softer, factory edges.
Ask forWhether the product is rectified, and edge straightness on samples.
02Technical classes
Reading a technical sheet
Two values buyers ask about most: water absorption, which places a tile in a product group, and slip resistance, which depends on the test method your market uses.
Water absorption groups
ISO 13006 groups dry-pressed tiles (group B) by water absorption (E), measured to ISO 10545-3.
BIa
E ≤ 0.5%
Very low absorption. Commonly described as porcelain.
BIb
0.5% < E ≤ 3%
Low absorption, vitrified body.
BIIa
3% < E ≤ 6%
Medium-low absorption.
BIIb
6% < E ≤ 10%
Medium-high absorption.
BIII
E > 10%
High absorption. Typical of glazed ceramic wall tiles.
Bars indicate increasing absorption; they are not to scale. The group of a specific product is stated on its test report.
Verify group limits against the current ISO 13006 / ISO 10545 editions
Slip resistance
There is no single global slip rating. Common methods include:
- Ramp test
- R ratings (for example R9–R13) to DIN 51130, used in parts of Europe for workplace floors.
- Pendulum test
- Pendulum test values (PTV), used in the UK, Australia and elsewhere, often for wet and dry conditions.
- DCOF
- Dynamic coefficient of friction (ANSI A326.3), referenced in North America.
Results are specific to the product and finish. What is required depends on the area of use and local regulations — check with your specifier or regulator, then ask us for the matching test report.
Verify slip-test references against the applicable standards
03Sample approval
An approved sample is your reference
Samples show the design, finish and body. Approving and keeping a reference set gives you and the partner factory a clear standard to compare production against.
-
You
Request samples
Choose products from the shortlist. Sample and courier charges are agreed with you first.
-
Thorson Tiles
Dispatch with codes
We send samples labelled with product codes, so feedback is precise.
-
You
Evaluate
Check size, thickness, shade, finish, flatness, edges and the back. Photograph them in daylight.
-
You
Approve a reference
Keep one approved set, dated, with codes and shade noted where available. This becomes the reference for your order.
-
Partner factory
Match production
Production is compared with the approved reference. Normal shade variation between batches still applies.
- Lay several samples side by side to judge shade and print variation.
- Measure size and thickness, and check that edges are straight.
- Look at the back of the tile for product markings.
- Ask whether production will come from the same batch as the samples or a new run.
04Inspection options
Three layers of checking. Ours on every order.
Partner factories run their own quality control, and we check every order before it is loaded. If your product, order value or market needs more, you can add an inspector you appoint. The scope is agreed before production, not after.
Our pre-shipment check
Before loading, we check every order on agreed points such as shade, calibre, quantity, packing and carton marking, and send you photos or videos of the packed goods.
Every order · points agreed in advance
Your own inspection agency
Want an independent check as well? You are welcome to appoint your own third-party inspection agency. You agree the scope and sampling plan with them; we arrange access and timing at the partner factory.
Optional · scope agreed in advance
If something is wrong after delivery, you contact us, not the factory. Thorson Tiles is the seller, so we handle the claim with you.
05Packing details
Packing details, confirmed per product
Packing varies by manufacturer and format. These details are confirmed for each product and stated in the quotation — never assumed from a generic table.
| Detail | Why it matters | Confirmed |
|---|---|---|
| Pieces per box | Sets how cartons and orders are counted. | Per product |
| m² per box | The basis for converting your m² requirement into boxes. | Per product |
| Weight per box | Container loads are usually limited by weight, not volume. | Per product |
| Boxes per pallet | Determines pallet count, stability and handling at destination. | Per product |
| Pallet type | Wooden pallets for export usually need ISPM 15 treatment and marking. Other pallet options can be discussed. | Per order |
| Corner protection & strapping | Protects edges and corners during handling and transit. | Per order |
| Carton marking | Product name or code, size, shade, calibre, quantity and origin on every carton. | Per product |
| Container loading | Palletised or loose loading, pallet count and permitted weight for the container. | Per order |
Verify ISPM 15 pallet requirements for each destination
Will all tiles in my order be the same shade?
Shade variation between production batches is normal for glazed and printed tiles. Tiles are sorted by shade and calibre, and these are marked on the cartons. For one project or area, order enough from a single batch and avoid mixing shade or calibre codes.
You can ask for each product to be supplied in a single shade and calibre where possible; this is subject to confirmation by the partner factory.
How is quality checked before shipment?
Partner factories run their own quality control during production. Before loading, we check every order, covering agreed points such as shade, calibre, quantity, packing and carton marking, with photos or videos of the packed goods.
If you also want independent verification, you are welcome to appoint your own third-party inspection agency. The scope and cost of any third-party inspection are agreed in advance.
What should I check when samples arrive?
Compare the samples against your specification: size and calibre, thickness, shade and print variation, surface finish, flatness, edges (rectified or not) and the back of the tile. Photograph them in daylight and keep one set as your reference. Our quality & packaging page lists what to look for.
Can you provide technical data sheets and test reports?
Where partner manufacturers provide them, yes. Values such as water absorption, breaking strength, slip resistance and dimensional tolerances are specific to each product and each test report, so we share the documents the manufacturer actually holds rather than generic figures.
If your market needs a particular test or standard, tell us at the start so we can check whether existing reports cover it or whether independent testing should be discussed.
Do the products carry certifications such as CE marking?
Certifications and declarations are specific to each manufacturer and product. We only share certificates and test reports that partner manufacturers actually hold for the product you are considering. If your market requires a particular certification, include it in your enquiry so it can be checked before quotation.
How many square metres fit in a container?
It depends on the format, thickness and packing of each product. Tiles are dense, so a container usually reaches its permitted weight before it is full by volume. The quantity per container is therefore worked out per product — and per mix of products — and confirmed in the quotation.
What happens if there is a quality problem after delivery?
You contact us, not the factory. Thorson Tiles is the seller, so we handle the claim with you. Share photos, carton labels and batch details, and we take it from there. How claims are assessed and settled is set out in the quotation and sales terms.
Have a specification to check? Ask us.
Tell us the product, your market’s requirements and the area of use. We’ll check what the factory’s test reports cover and what still needs confirming.