Pumice Liner System Chimney Internal – Video


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Construction begins by providing a suitable foundation and constructional hearth in accordance with Building Regulations and site requirements.


Our pre-stressed lintels must be installed above the fireplace recess , for this method a support plate is required under the support block. Alternatively a suitable cast-in-situ concrete slab lintel can be created above the fireplace recess. (See Isokern standard drawings for hole size depending on diameter of chosen flue). The support block is bedded onto the slab lintel using weak mix mortar. A stainless steel adaptor is used to connect from the support block to the stove flue pipe. This adaptor is pushed up onto the support block spigot (fibre rope should be used to create a seal). It is recommended to have a minimum of 600mm length of flue pipe before connecting to the chimney.


A soot door must be provided below the flue pipe entry to allow for inspection and removal of soot and debris. A suitable wall sleeve is to be used to seal the cavity wall. Any combustible insulation within the wall must be kept away from the single skin connecting flue pipe by at least 1.5 x its diameter. A stainless steel adaptor is fitted to the Isokern T Liner with the fibre tape supplied. The flue pipe is a push fit over the spigot on the adaptor. Seal off the gap between the flue pipe and wall sleeve with fire proof rope and closing plate.



Install the firechest onto the constructional hearth using lip glue making sure all elements are level. 100mm of brick or blockwork must be built around the sides and back of the firechest to comply with Building Regulations. The inside of the firechest must be finished with a suitable fireback or firebrick slips.

Install the gather using lip glue making sure all elements are level. The front face of the gather can be finished with plasterboard, rendered or clad in masonry. Lintels may
be required above the gather to help carry the brick or blockwork. The maximum loading capacity of the Isokern firechest and gather is 2500kg.