Type of appliance

Nominal heat output




Flue diameter

Fuel type

Clearance to combustibles at side

Clearance to combustibles at rear


Why Pumice is the best lining material for a new chimney

When considering the building of a new chimney, there is an often bewildering array of materials and options to choose from. We think our Isokern pumice flue liners and modular flue systems represent the best, safest and most cost-effective product on the market. Unlike clay or cement liners, pumice – a volcanic stone - is a superb insulator and is highly resistant to the significant temperature changes you can expect to take place in a functional chimney. In practice, this makes it incredibly durable, and enhances the performance of your stove while minimising the chances of smoke condensing in the flue. As a material, it is also lightweight, allowing for ease of installation, and our pumice components come in modular components easily handled by one person. 

A good chimney keeps you safe, warm and happy. A good chimney is also an easy one to design and build: Isokern’s Pumice Double Module system is a perfect example. Its unique design of two layers of volcanic rock separated by an air gap gives you the freedom to situate your chimney anywhere within the curtilage of your property, with zero distance to combustibles, and their lightweight block construction and lego-like assembly make them easy to assemble on site.

Key features of the DM module system are:

•             Zero distance to combustibles on straight rendered chimneys (when using top ring terminal)

•             Quick and easy to assemble

•             Lightweight materials, easy to handle

•             Highly insulating pumice for better draw and minimum heat loss

•             Staggered joints for maximum safety and stability

•             Air gaps between outer casing and flue prevents surface staining

•             Good resistance to temperature variations gives the maximum performance for your appliance.

•             CE Certified to EN1858 with the designation T450, NI, D, 3, G (00).

For more information on the Isokern range, contact the New forest Wood Burning Centre at [email protected] or email [email protected] direct . You can also visit,

 which is full useful of information, including a number of video instruction guides on the DM system and other Isokern chimney options.

diagram of a pumice flue system for a stove in fireplace recessdiagram of pumice flue system for free-standing stovediagram of pumice flue system for inset stove