ISO ≠ ANSI: Understanding Tile Standards for the U.S. Market
Make sure your imported tiles meet U.S. requirements with ANSI A137.1 testing
If your products are tested to ISO 13006, they may not comply with the standards recognized in the American market.
Let’s break down why and how to make sure your tiles meet expectations for U.S. distributors, retailers, and contractors.
Why This Matters
Tile standards define quality and performance.
In the U.S., the tile industry relies on ANSI A137.1, the American National Standard Specifications for Ceramic Tile. In fact, U.S. commercial specifications for ceramic tile installations require compliance with ANSI A137.1, and it is referenced in building code.
Most international manufacturers test products to ISO 13006, but these two systems use different test methods and performance thresholds — which means results aren’t interchangeable.
When tiles tested only to ISO are imported without further verification, they may:
- Not meet key U.S. requirements
- Cause costly rejections or warranty claims
- Lead to confusion in the supply chain
If you’re distributing or importing tiles for sale in the U.S., your customers — retailers, installers, and specifiers — expect compliance with ANSI A137.1.
Key Differences Between ISO 13006 and ANSI A137.1
Even though both standards aim to measure tile quality, there are important differences between the two.
Some performance areas required in ANSI simply don’t exist in ISO, including bond strength, DCOF, and mosaic tile criteria in general. This means products tested to meet ISO 13006 are missing key performance factors.
Even when similar tests exist, there are instances where ANSI A137.1 specifies tighter tolerances and higher performance thresholds. This is seen in the various dimensional criteria, crazing resistance, and freeze/thaw resistance.
In the case of breaking strength, tests referenced in ISO and ANSI use entirely different methodologies.
We’ve created the following page to provide detailed information on the differences between ISO and ANSI specifications.
If your products are tested to ISO 13006, they may not comply with ANSI A137.1.
Here is where they differ:
| ANSI A137.1 (ASTM) | ISO 13006 | Notes | |
|---|---|---|---|
| Bond Strength | Required (ASTM C482) | Not required | ANSI A137.1 adds this essential test. Bond strength is an important evaluation to ensure the proper bond of the tile to a substrate can be achieved. If not tested, bond issues can arise years after installation. |
| Breaking Strength | ASTM C648 (point load) | ISO 10545-4 (3-point bend) | There is no way to determine if a product will meet ANSI A137.1 breaking strength criteria from the ISO test result. Strength is of upmost importance when it comes to ensuring the durability of an installation |
| Crazing Resistance | Up to 150 psi steam pressure (ASTM C424) | Up to 75 psi steam pressure (ISO 10545-11) | ANSI A137.1 requires testing at double the pressure of ISO. This more stringent test requirement can avoid problems with crazing once installed, something that can’t be fixed without ripping old tile out and replacing it completely. |
| Freeze/Thaw Resistance | 300 cycles, full saturation (ASTM C1026) | 100 cycles, partial saturation (ISO 10545-12) | There are products that show no damage during ISO testing but have issues with the ASTM C1026 test method. The ASTM method requires 3x the number of freeze/thaw cycles than the ISO method. Additionally, the ASTM method requires the product to be fully saturated before testing, then during the freezing cycle the tile sits within the water bath creating the possible extreme conditions tile may have to endure when installed in freeze/thaw applications. |
| Dynamic Coefficient of Friction (DCOF) | Required (ANSI A326.3) | Not covered | It is essential to understand slip resistance characteristics of a flooring material. Without this information, the product may be used in an inappropriate application, leading to potentially dangerous conditions. |
| Dimensional Tolerances | Tighter limits on variation (ASTM C485, C499, C502) | Broader tolerances (ISO 10545-2) | Less stringent tolerances may lead to difficulties installing and even failures due to lippage or other spacing problems. |
| Mosaic Tiles | Included | Not covered | This is a very popular product category that isn’t covered in ISO at all. ANSI A137.1 has a table of criteria for mosaics that has requirements like all other tile products. There is no reason a mosaic product shouldn’t be held to the same level of scrutiny. |
Bottom line: Meeting the ISO 13006 specification does not guarantee compliance with ANSI A137.1.
Testing to Confirm Compliance
At IPA Laboratories, we specialize in testing tile products to both the American and International standards. Our level of expertise is unmatched as many of the standards are developed using research performed in our lab.
We’ve developed focused testing packages to evaluate tile products to ANSI A137.1, including the full scope or only the areas where ISO and ANSI differ, saving you time and cost.
ANSI A137.1 Full Evaluation
A comprehensive test package designed to evaluate all required performance characteristics for ceramic, porcelain, and mosaic tiles under the ANSI A137.1 standard.
ANSI A137.1 Missing Criteria Evaluation
Targeted testing for imported tiles that have ISO 13006 test results but are missing (or not equivalent to) required ANSI A137.1 tests. Includes:
- For Glazed Tiles – Breaking strength, bond strength, freeze/thaw, crazing, DCOF, dimensional testing
- For Unglazed Tiles – Breaking strength, bond strength, freeze/thaw, DCOF, dimensional testing
