Chimney Stacks
Close-up of typical ‘late’ type chimney stack with original pots.
According to one estimate, at least four out of every five chimney stacks have been removed over the past few decades but the good news is that open fires are once again becoming popular, even if only used on special occasions. Having a chimney stack in your house can have other benefits too. An open flue, especially when there is a fire burning, can help reduce the build up of condensation inside our houses during the winter months as the air circulation is greatly improved. During the summer months, the open flue also helps to keep our houses cool, as warm air is drawn up the flue and fresh air enters the room through open windows and vents. Therefore, if you still have your open fire and your chimney stack, it makes sense to keep them.
‘Early’ type chimney stack built of stone.
Where an original stack has been reduced in height (often capped with concrete slabs) then it should be rebuilt to their original height. Where no evidence of the pattern of the original stack exists, the style should be kept simple, but always with oversailing corbelled courses at the head. The height and size of the stack may be determined by checking the number of flues served and relating to similar stacks on adjacent roofs.
Any surviving chimney stack, because of its exposure is likely to need repointing at least. Guidance on pointing brick and stone is given in the section on wall surfaces.
In repairing or rebuilding brick chimney stacks, clay bricks of matching colour should always be used. Bricks can be reclaimed or new but should, if possible, be imperial size, not metric. In certain cases where repair of a known pattern is being carried out, purpose made specials may be required etc. These can be obtained from specialist brick companies.
Chimney stacks add to the strong rhythm that make the Valleys terrace special.
If possible, concrete bricks should be avoided and chimney stacks should not be rendered. Lead flashing at chimneys should be stepped in the traditional manner and to Lead Sheet Association details. Do not cut out a chase on the slope and insert single lengths of lead cover flashing.
Stone or brick chimney stacks?
Chimney stacks to the earliest Valleys houses were more often than not built of stone but as time went on brick corners were introduced to make their building easier. Eventually all chimney stacks were built of brick, often using more than one colour.
Whenever repair works are carried out to chimney stacks it is important that the original form and materials are retained. Should your original chimney stack be beyond repair, or already removed (but the internal breast remains), then rebuilding is an option that should be given consideration.
Size, scale and pots
Various types of chimney pots. The one on the right is the most common.
The single most important point regarding rebuilding a chimney stack is that it should be of the right size and scale for the house. Rebuilding a reduced size chimney stack is, visually, worse than not having a chimney stack at all. It is important therefore that you find out what type of stack existed previously. Was it built of stone, a mixture of brick and stone, or just brick? What size was it, and did it have any decorative patterns or special details? What type of chimney pots did it have?
The answer to these questions can sometimes be found by looking carefully at chimney stacks and pots that have survived in the same street or in similar aged houses in nearby streets. If four out of every five houses had their chimney stacks reinstated the character of our streetscape would be enhanced and the inside of our houses could benefit too!
