A chimney stack, if not built correctly, provides a very good way for rainwater to penetrate
the roof, resulting in water damage reaching down to the chimney breast in the living rooms. Once this
state of affairs is reached it is very expensive to rectify.
The following series of photographs illustrate the process of constructing a stack, including
some detail on preparing the lead apron and flashings.
Note. If a new build, your architect will have specified engineering bricks, if not, then ensure you use
engineering bricks - do not use porous bricks.
For this and other building work, buy
building materials from
Click on the photos for a larger view
You may also be interested in building the chimney flues
Stop the blockwork at the point at which it is just "emerging"
from the roof. Complete filling the void around the liners with the vermiculite
cement and level it with the top of the blocks. The liner has been cut to finish slightly
above the blocks.
A lead tray has been formed on a bench, a hole cut in the centre
and a lip dresed up 50mm high. The tray has 3 coats of patination oil on both sides. The diameter of the finished upstand should fit it inside
the chimney liner. The tray is domed slightly as the liner is cut slightly higher than the blocks
- this will ensure any water flows outward.
The next liner has slits cut into it at the base and it is fitted over
the lead upstand - any water going down the chimney will be channeled through the slits by the lead.
The lead flashings are accurately measured, cut and formed before
the application of patination oil.