Understanding Martindale Ratings and Crib 5 Requirements

Martindale and Crib 5 appear on almost every contract fabric data sheet, and they are routinely misquoted. Understanding what each one measures helps you specify seating that is both durable and compliant for its setting.

What the Martindale rating measures

The Martindale test measures a fabric’s resistance to abrasion, how well it stands up to rubbing over time. A sample is rubbed in a figure-of-eight motion against a standard abradant, and the number of cycles ("rubs") the fabric survives before showing wear gives its Martindale rating.

What the numbers mean in practice

As a rough guide: under 20,000 rubs is domestic only; 25,000-40,000 is suitable for general domestic and light contract use; 40,000 and above is the sensible minimum for commercial seating; and 60,000-plus suits heavy-use public and high-traffic settings. A higher Martindale score does not automatically mean a better fabric, it is one factor alongside fire rating, appearance retention and cleanability, but it is a reliable durability benchmark.

What Crib 5 means

Crib 5 refers to ignition source 5 in the BS 5852 fire test, a small wooden "crib" that is lit against the upholstery to simulate a more severe ignition source than a match or cigarette. Passing Crib 5 means the fabric-and-filling combination resists that ignition source without sustaining combustion. It is the level of fire performance normally required for contract and commercial seating in the UK.

How Crib 5 fits into BS 7176

BS 7176 classifies upholstered commercial furniture by hazard: low, medium and high. Most offices and many hospitality settings are medium hazard, which generally requires the Crib 5 (ignition source 5) test to be met. Higher-risk settings such as some healthcare and public buildings may require high-hazard performance. Always specify to the hazard category for the actual setting.

Inherently FR versus FR-treated

A fabric can achieve fire performance either because its fibres are inherently flame-retardant, or because it has been treated with a flame-retardant back-coating. Inherently FR fabrics keep their performance for the life of the fabric; treated fabrics can lose performance over time and with cleaning. For long-life, heavily-cleaned settings, inherently FR is often the better specification.

What to ask your supplier

Request the Martindale figure and confirmation of the fire test for the exact fabric and filling combination you are specifying, not just the fabric in isolation. If you are supplying your own fabric, the frame maker will usually need it fire-tested or treated before it can be used. We can confirm the ratings for fabrics across our ranges and advise on compliant options for your setting.