Chapter 10 case study 2: Flues and chimneys 

The brick chimney stack seen here houses the flue to the gas fire or boiler. The existence of a stack is not strictly necessary in modern construction, as there are other ways to deal with flue outlets. It has become more of an aesthetic feature. Note the two visible flashings/DPCs, required to prevent moisture ingress into the building from the stack.

Here we see the outlet from a series of flue blocks embedded within the external wall. The darker blocks are dense concrete flue sections, assembled as the wall is built to create a continuous flue. In this case the outlet into the roof void will be connected to a metal flue section before exiting at ridge level.

The gas appliance is housed within a heat-proof enclosure as seen here. The yellow pipe seen to the left is the gas supply and is colour coded in the same way as the entry supply pipe discussed in the early part of the book.