It’s no longer…pot luck!

WT Knowles have certified their range of chimney pots against the British Standard BS EN 13502:2002 so you know you’re using the right…tool…pot for the job.


In a rapidly evolving industry such as roofing, keeping up with changing standards and directives is an ongoing job. For example, where chimney pots are concerned, trying to understand which pot should be used on which application and if what was installed previously meets today’s legislation and standards can give you a bit of  a headache. What should you use on solid fuel? gas? or if the client has a decorative fuel  effect fire (DFE)? and how can you be certain that the selected pot meets current regulations and standards?


Fortunately, all that is a thing of the past as WT Knowles, the clay chimney pot manufacturer, have recently completed a full review and re-classification of a large part of their range with the help of the British Standards Institute (BSI).

Standard BS EN 13502:2002 covers chimneys and specifically the requirements and test methods for clay and ceramic flue terminals. The Standard defines certain designs of clay terminals as:

  • Type 0 – Open topped terminals with no flow restrictions
  • Type 1 – Restricted flue terminals
  • Type 2 – Restricted flue terminals with a resistance factor not greater than 5

Type 0 terminals don’t need aerodynamic testing and are used exclusively on solid fuel applications, whereas Type 1 and Type 2 terminals do require aerodynamic testing.

As a result of the testing, WT Knowles  now has 19 ranges certified as Type 0,  12 ranges as Type 1 and 13 ranges as  Type 2. The testing specification also included acid resistance and freeze/thaw resistance of the clay material used in the manufacture of all flue terminals. This  was also carried out by BSI and is recorded on the certificate. All flue terminals are stamped in accordance with the requirements of BSI Standard  BS EN 13502

To help contractors further there’s a handy Chimney Pot Classification guide available that shows you which pots to use for different types of job. In the guide the company recommends using Type 0 and Type 1 pots on solid fuel, Type 1 (DFE) pots on multi-fuel and Type 2 pots exclusively on gas applications. For a  copy of the guide, fill in the reader response card.