Cold Crack Temperature Testing for Coated Fabrics: A Specifier’s Guide

What it measures: The lowest temperature at which the surface coating of a faux leather or coated fabric cracks when flexed.
UK standard: BS EN ISO 17233, the UK-adopted form of the international ISO 17233:2017 method.
Typical performance: Standard PVC begins to stiffen around 0 degrees Celsius and may crack below minus 5 degrees. Cold-resistant formulations can be specified to withstand minus 20 degrees or lower.
When it matters: Marine exterior use, outdoor terrace furniture, and any cold-climate installation.

Cold crack temperature is a performance property that determines whether a coated fabric will survive flexing in cold conditions without its surface fracturing. It is rarely discussed in standard upholstery specification because most interior fabric is used in heated environments where it is not relevant. For coated fabrics used in exterior, marine, or cold-climate applications, it is one of the most important specification questions and one of the least frequently asked. This guide explains what the test measures, what the results mean, and when to request the data.

For the broader comparison of coated fabric types, see our faux leather types compared guide. For exterior and semi-outdoor specification, see our outdoor terrace fabric specification guide.

Why Coated Fabrics Crack in Cold Conditions

PVC is a rigid polymer in its raw state. To make it flexible enough for use as a faux leather, plasticisers are added. These are compounds that sit between the polymer chains and allow them to move relative to one another, giving the material its flexibility and soft handle. The behaviour of these plasticisers at low temperatures determines the cold performance of the finished fabric.

As temperature falls, the polymer approaches its glass transition point, the temperature at which it changes from a flexible state to a hard, brittle one. Below this point, the material no longer flexes; it fractures. If a coated fabric is flexed or stressed while in this brittle state, such as when someone sits on an exterior cushion in cold weather, the surface coating cracks. These cracks deepen over time, expose the backing fabric, and lead eventually to complete surface failure.

The glass transition point is not fixed. It depends on the plasticiser chemistry used in the specific formulation. Standard general-purpose plasticisers give a relatively high transition point, meaning the material becomes brittle at temperatures only slightly below freezing. Specialist low-temperature plasticisers give a much lower transition point, keeping the material flexible well below minus 20 degrees Celsius.

The Test: BS EN ISO 17233

The cold crack temperature of a coated fabric is determined by BS EN ISO 17233, the UK-adopted form of the international ISO 17233:2017 method. It specifies a procedure for determining the temperature at which the surface coating of a flexible coated material cracks.

The method conditions test pieces at a series of decreasing temperatures. It begins at 0 degrees Celsius and steps down in defined increments, minus 5, minus 10, minus 15, minus 20, minus 25, and minus 30 degrees Celsius, using fresh test pieces at each stage. At each temperature the conditioned test pieces are flexed and examined for cracking. The cold crack temperature is recorded as the temperature at which the surface coating of at least two test pieces cracks.

The result is a single temperature value. A fabric with a cold crack temperature of minus 20 degrees has demonstrated that its coating remains intact when flexed at temperatures down to that point. A fabric with a cold crack temperature of minus 5 degrees will crack if flexed at any temperature below that.

US Equivalent Test Methods

Two ASTM methods are used in the United States for equivalent cold performance testing and may appear on data sheets for material of US origin. ASTM D2136 is a low-temperature bend test for coated fabrics, a pass or fail procedure at a specified temperature. ASTM D2137 determines the brittleness point of flexible polymers and coated fabrics. Where a data sheet cites an ASTM result rather than a BS EN ISO figure, confirm the test temperature and criteria, as the methods are not directly interchangeable with the BS EN ISO 17233 stepped procedure.

What Results to Specify by Application

The cold crack temperature required depends on the lowest temperature the fabric will experience in service, including overnight and seasonal extremes, not the average temperature.

Interior heated environments. Cold crack temperature is not a relevant specification criterion. Any standard coated fabric performs adequately in a permanently heated interior.

Covered exterior and semi-outdoor. Hotel terraces, covered courtyards, and similar spaces that are unheated but sheltered experience temperatures down to local winter minimums. In the UK this means specifying for temperatures that can fall several degrees below freezing overnight in winter. A cold crack temperature of minus 20 degrees provides a safe margin for UK exterior use.

Marine exterior. Deck seating and exterior cushions on vessels experience both low temperatures and constant flexing from use and from the movement of the vessel. Marine exterior applications should specify a cold-resistant formulation with a confirmed cold crack temperature well below the coldest expected operating condition.

Cold-climate installations. Projects in continental or northern climates where winter temperatures fall well below UK minimums require correspondingly lower cold crack temperatures. Confirm the coldest expected temperature at the installation location and specify a margin below it.

Silicone Leather and Cold Performance

Silicone leather does not use plasticisers. Its flexibility is a property of the silicone polymer itself rather than of added compounds. This means it does not have the plasticiser-driven glass transition behaviour that causes PVC to crack in cold conditions. Silicone leather remains flexible across a much wider temperature range than PVC and is the more reliable specification for applications combining cold exposure with constant flexing. This is one of the specific properties that justifies its price premium in exterior and marine applications. For the full comparison, see our faux leather types compared guide.

What to Ask the Supplier

For any coated fabric being specified for exterior, marine, or cold-climate use, request the cold crack temperature determined by BS EN ISO 17233, expressed as a specific temperature in degrees Celsius.

Confirm whether the figure applies to the specific colourway and finish being specified, as formulation can vary across a range.

Where the fabric is of US origin and the data sheet cites an ASTM result, request the test temperature and pass criteria so the result can be interpreted against the UK application requirement.

For marine and exterior applications, confirm the cold crack figure alongside the UV and light fastness data, since these applications combine cold exposure with sustained sunlight and both must be satisfied.

Quick answers

What is cold crack temperature for faux leather?
Cold crack temperature is the lowest temperature at which the surface coating of a faux leather cracks when flexed. It is determined by BS EN ISO 17233, the UK-adopted form of the international ISO 17233:2017 method, which conditions test pieces at decreasing temperatures from 0 degrees Celsius down to minus 30 and records the temperature at which the coating fractures. Standard PVC typically cracks below minus 5 degrees; cold-resistant formulations can withstand minus 20 degrees or lower.

Why does PVC faux leather crack in cold weather?
PVC is made flexible by adding plasticisers. As temperature falls, the polymer approaches its glass transition point, below which it becomes hard and brittle rather than flexible. If flexed in this brittle state, such as when someone sits on an exterior cushion in cold weather, the surface coating cracks. The transition temperature depends on the plasticiser chemistry: standard formulations become brittle just below freezing, while specialist low-temperature formulations remain flexible below minus 20 degrees.

What cold crack temperature should I specify for outdoor use?
Specify for the lowest temperature the fabric will experience in service, including overnight and seasonal extremes, not the average. For UK covered exterior and semi-outdoor use, a cold crack temperature of minus 20 degrees Celsius provides a safe margin against winter overnight lows. Marine exterior and continental cold-climate installations require correspondingly lower figures. Confirm the coldest expected temperature at the installation location and specify a margin below it.

Does silicone leather crack in the cold?
Silicone leather does not use plasticisers, so it does not have the glass transition behaviour that causes PVC to crack in cold conditions. Its flexibility is a property of the silicone polymer itself and remains stable across a much wider temperature range than PVC. This makes silicone leather the more reliable specification for applications combining cold exposure with constant flexing, such as marine deck seating and exterior furniture, and is one of the properties that justifies its price premium.

Is cold crack testing the same as the ASTM cold bend test?
They measure the same property but are not directly interchangeable. BS EN ISO 17233 is the UK and international method, using a stepped procedure that records the temperature at which the coating cracks. ASTM D2136, used in the United States, is a pass or fail bend test at a single specified temperature, and ASTM D2137 determines a brittleness point. Where a data sheet of US origin cites an ASTM result, confirm the test temperature and criteria so it can be interpreted against the UK application requirement.

For the full comparison of PVC, PU, and silicone leather including durability and fire certification, see our faux leather types compared guide. For exterior and semi-outdoor fabric specification, see our outdoor terrace fabric specification guide.