The Dunbrik Mini Clearflow gas flue block system is a neat, efficient method of providing a flue in new domestic dwellings. Gas fires suitable for "pre-cast flues" may be fitted - these are Class two gas fires which are usually under 7kW input and include efficient live fuel effect gas fires.

Three sizes of recess opening are available to suit different fire sizes and chimney breast arrangements. The flue outlet depends upon the house design. It is usually through twin-wall flue pipe to a ridge vent or to a gas terminal at eaves or through the roof slope. Alternatively a traditional chimney stack can be built at eaves or gable/party wall.

The gas flue blocks are built into and bonded with house walling. This can be into the inner leaf blockwork of an outer wall, into a party wall or partition wall. In many cases there is no chimney breast intruding into the living area.

The gas flue blocks are designed for ease of installation. The tongue and socket detail provides a tight concrete-to-concrete internal joint and an external compressive seal using special heat-resistant sealant. The bonding nib has a 10mm cut-out for mortar jointing with the adjacent blockwork - this assists coursing.

The flues blocks are made of concrete and comply with British Standards BS1289 Part 1. The flueway is rectangular 185mm by 90mm giving a flue cross sectional area of 16,650 sq.mm. The flue block walls have a minimum thickness of 25mm.

The Dunbrik Mini Clearflow is the best selling gas flue block system on the market.