Chimneys

Published: Monday, 13 May 2013

We never look at domestic chimneys, but they are amazing. Sometimes you might look up and look at chimney pots and fireplaces, but do you ever look at the chimney itself?

If you live in a house with chimneys you probably look at the alcoves at the side of the fire. Maybe yours are filled with shelves? Before TV a lot of people used to watch the fire and before electricity read by its light so when television came out they put the sets next to the fireplace in the alcove. Nowadays most of us in the UK don't have open fires so chimneys usually stick out into the middle of the room and take up a lot of space and sometimes you wonder why they are there.

If you have ever tried to undertake large scale building work or make structural changes to an old house you may have found out what a pain a disused chimney can be and how having it there can make the work much more expensive. If you take away the bottom part there is a danger that the top of the stack might collapse downwards and cause huge damage. To take away the top of the stack can cause problems because you might have to undertake extensive work on the roof before you start in the rooms below. If your chimney forms part of an adjoining wall, removing it might cause insurmountable problems unless you are willing to carry your building work through to your neighbour's house.

If they cause so many problems why would anyone think they were an amazing invention? Read on...


Houses didn't always have chimneys. One kind of house or another has been around for thousands of years. In comparison the chimney as we know it has only been around a few hundred years. Although many Roman buildings had them, they died out when the Romans left Britain.

At first in large timber framed houses the fire was usually in the middle of the building. The smoke would drift high up to the top of the roof and there may be a little opening in the centre or, in open hall houses, there would often be vents at either end of the roof right up at the apex and wind would blow smoke through the house until it left by one end or the other.

Not all houses had anywhere for the smoke to go. If you had a hole in the roof the heat might escape too quickly. On the other hand if you didn't, you might have a warmer house, but the roof above the fire may have become very hot and there could be a danger of fire.

Something to do!

Smoke that stays in the house will keep it warm, but the house will be very smoky and might be unpleasant to live in. Also the roof might get very hot with nowhere for the hot air to go.

With a draft blowing through the house fanning the fire, maybe sparks would fly up towards the roof. That would be dangerous. Some of the smoke would escape leaving the house colder but also maybe easier to live in. Rian may get in too if there was a hole in the middle of the roof. Not eveyone would want that!

In open hall houses people would sleep on the upper story where the warm air would drift. Presumably a house with no chimney or vent suffers from similar problems to a round house with no ventilation and the air might be quite polluted.

 

A through draft might leave different ends of the house warmer or cooler depending on which way the wind was blowing. On the other hand it would cool the roof and possibly blow the warm air towards the bed chambers in the coldest weather.

Benefits

In medieval and Tudor times a fireplace and chimney would have been a status symbol as well as a useful household modernisation and they can still make a grand statement even in modern houses. In large houses the owner would usually move the fire away from the centre of the room towards an inner wall. This helped support the chimney breast itself, moved the fire out of the way making space and ensured that the walls to adjacent rooms could receive some of the heat from the chimney stack. In small houses the fire might be moved to one end.

One reason people lived in houses with huge high roofs was because the thatch had to be kept a long way away from the flames and sparks of an open fire. With a high roof you ended up heating a vast amount of empty space and that was extremely wasteful and expensive, but when chimneys became popular they ensured the smoke and sparks would rise up and out of the house away from the thatch and there was no need to have such a huge gap between the roof and the fire. Of course land was expensive and no one was going to pull down the house and make it single story, instead they were able to put in ceilings and additional floors above the main floor. Then the chimney breast would partly heat the upper rooms; even better, in the upper rooms the alcoves by the chimney breast were very useful warm dry storage areas.

Surprisingly Tudor houses often had smaller rooms than their earlier counterparts. The enclosed fire and chimney stack were largely responsible for this trend. Fuel was expensive and there was now no need to heat huge unused voids above a central fire. The houses started to become warmer and as the land was rapidly becoming deforested the rich turned to coal which was safe to burn in the new enclosed fireplaces. Even so flat glass for windows was still rare during much of the 17th and 18th centuries and only the rich could afford it until well into the 18th century so houses wouldn't have been as warm as ours are now.

The way rooms were laid out also changed. In the cruck and open hall style of house the owner would often sit behind an impressive table. Visitors would have to approach the table walking past the fire and may have been over-awed by the wealth, opulence and status of the owner which could be on show around the main hall.

With the trend to put a fireplace against the wall the people who dwelt in the house would often sit in high backed chairs that kept out the drafts facing the fire, possibly facing away from the main entrance. In time the fireplace itself would be built to not only be extremely large and useful, but be built to impress. For hundreds of years fire places were the focal point of many rooms.