 we are often asked by the purchaser to look at the practicalities of opening up sealed fireplaces and re-using flues that may have been redundant for many years.
The strange thing is that we never really seem to have lost our fascination with fire and it is amazing how many modern houses and flats that I survey where the focal point of the living room is a dummy fireplace.
We think that’s enough of the history for the time being and we’ll turn our attention to some of the practicalities.
The majority of the fireplaces and chimney breasts that we come across will be in houses dating from the late Georgian period up to the 1950’s. (As we’ve said above, many of the houses built from the 1960’s onwards were built without working fireplaces.) The fireplaces, chimney breasts and flues in these properties are generally of traditional brick construction. The actual fire surrounds are in a variety of materials. Cast iron fire surrounds were common in the Victorian and Edwardian era and these can range from quite simple to extremely ornate designs. These tended to be superseded by the tiled fire surround in the 1920’s and 1930’s and tiled surrounds continued to be popular until the demise of open fires in the 1960’s.
In theory chimney breasts are quite simple brick constructions. If a property has only one fireplace this is also the case in practice. In the simplest case the fireplace in the living room is connected to the chimney stack at roof level by a single brick flue. Each fireplace has to have an individual flue, however, and in a multi-storey property this starts to get complicated. A further complication is that in a terraced house the chimney breasts are usually on the party wall and this means that the fireplaces in one house will normally back onto the fireplaces in the adjoining house.
If we take as an example a five-storey, Georgian, terraced house with the chimney breasts on the party wall, we could potentially have ten flues running through the same chimney breast! You only have to look up at the roofs of some Georgian and Victorian terraces and count the pots on each stack. This will tell you how many flues and fireplaces the house originally had.
When we look inside a period house we see what we tend to think of as a fairly massive brick structure protruding from the wall. In most cases this is not, in fact, a solid brick structure, but a honeycomb of hollow flues.
The chimney breasts and flues in older properties were built in traditional brickwork and lime mortar and were built up as the walls of the house were raised. It was quite an art for the bricklayer to connect the right flues to the right fireplaces and make sure that they all avoided each other. For this reason flues in older properties rarely run in a completely vertical line from bottom to top; it is normally necessary for the flues to be off-set at some point to avoid fireplaces on the floors above.
Traditionally brick flues were almost always 225mm (9”) square internally. The main reasons for this were that it was a practical size for the efficient escape of flue gases and it was also the standard length of a brick. As I mentioned there is often a honeycomb of flues in the same chimney breast and the ‘wall’ separating two adjoining flues was generally 112mm (4 ½ “) or ½ a brick thick. The brickwork dividing two flues is also called the ‘withe’.
Traditional brickwork in lime mortar is not particularly airtight and in order to minimise any leakage of flue gases the flue was ‘parged’ or ‘pargetted’ internally as it was built. The pargetting would consist of a fairly rough coat of lime mortar. This deteriorates over the years and often becomes loose and cracked and can also be dislodged when the flues are swept. It is also not unknown for individual bricks in the ‘withe’ to become dislodged over the years with the result that gases from one flue could leak into the adjoining flue.
When surveyors carry out either Building or Homebuyer Surveys they will not be able to assess the internal condition of an old flue and their report will normally contain a 