A specification that says only "fire rated" does not contain enough information to select a product. The two hydrocarbon fire scenarios that matter behave differently enough that a material can pass one comfortably and fail the other outright.
Pool fire
A pool fire is burning liquid: a large flame, relatively low velocity, dominated by radiant heat transfer. Temperatures rise very fast compared with a cellulosic building fire, which is why hydrocarbon test curves such as UL 1709 exist. The challenge for a protective material is surviving intense heat for the required duration.
Jet fire
A jet fire is a pressurised release igniting as a high velocity jet. It adds a mechanical component: the jet erodes the protective material at the same time as it heats it. Intumescent coatings that char and swell can have that char stripped away by the jet, leaving bare steel. This is why jet fire is tested separately, typically to ISO 22899-1, and why passing a pool fire test tells you little about jet fire performance.
The common specification mistake
Specifying a duration and a temperature without specifying the fire type, then accepting a product approved for the other one. This happens most often when a product is substituted late in procurement on the basis of a similar description. Approvals are granted for a specific product, tested to a specific standard, installed to a specific detail. Change any of those three and the approval does not carry over.
What to put in your specification
- The fire type, jet or pool, stated explicitly
- The test standard and the required duration
- The substrate and the critical temperature criterion
- Whether the protection must also serve as thermal insulation in normal operation
- That substitutions require test evidence against the same standard, in writing
How we handle it
Tell us the standard, fire type and duration your specification calls for and we will confirm in writing what we can support with test evidence before you order. If we cannot support your requirement we will say so rather than offer a nearby product and let the difference be discovered later.
