Isokern Concrete & Pumice Gathers
Isokern make a range of concrete and Pumice gathers to suit open fire installations.
Isokern Concrete Gathers are made using re-bar re-enforced concrete and made in a variety of sizes to suit different size flue requirements. Concrete gathers can support the weight of the liner and light expanded clay aggregate as required. Isokern Concrete Gathers are designed for chambers from 600mm wide up to 800mm wide You can increase the chamber size width by using lintels, but the overall finish size of the fireplace opening (width an height) does require the flue sizing accordingly and may affect performance.
Isokern Pumice Gathers are made using pumice to maximise performance. Pumice gathers can support the weight of the liner and light expanded clay aggregate as they have been specifically designed for Isokerns Liner or Double Module System. these Gathers are designed for chambers upto 690mm. As above ou can increase the chamber size width by using lintels, but the overall finish size of the fireplace opening (width an height) does require the flue sizing accordingly and may affect performance, so please take proffesional advice on the flue and any structural element.
UK regulations require a minimum flue cross section of 15% the total opening, this calculation will generally achieve a open fireplace that performs as required and will minimise the risk of spillage into the room. Flue gathers are generally used for open gas or solid fuel fires beneath. If you are installing an appliance with a flue spigot such as a wood burning stove, then Isokern make a support block which come with optional stainless steel adapters for a safe and long lasting joint.