Mutual and gable chimneys

Mutual chimneys will often carry flues from the neighbouring tenement, as well as from your own, and costs will be shared between both tenements. 


Cross wall

Often made of brick inside the loft


Chimney flashing to skew

More about flashings



More about roof timbers and your loft


Mutual and gable chimneys are built at the top of cross or gable walls. The mutual chimney is shared between two neighbouring buildings. However, even in older stone tenements, the wall below a mutual chimney is generally made of brick (gable walls in older tenements are commonly built in a rubble or rough finished stone).

As the flues feed up through the walls, the stonework can be quite thin in some areas. The stone is vulnerable to decay, particularly high up where the flues gather and it is exposed to the weather.

gable end uncovered crop lite.jpg
A brick cross wall John GilbertExposed by demolition of the neighbouring building.
gable chimneyDSC 2089 crop lite.jpg
Stone gable wallJohn GilbertNote the decayed stonework where the flues run.

Along with the skew, mutual chimneys form a firebreak between two tenements. Gaps in the wall inside the loft will allow smoke and fumes to escape into the loft and allow fire to spread to neighbouring properties. 

Mutual chimneys share many of the repair issues that affect all chimneys, such as problems with copings, stonework, render, flashings, and pots.

See chimneys for more information on defects

Professional help recommended?

Although the work may appear straightforward, ensure your builder or tradespeople have the skills for the job. If in any doubt, get professional help to specify and organise the repair.

Further information

Historic Scotland Inform Guide 'Domestic Chimneys and Flues'