In its 27th year now, the NACS was set up to promote high standards for the sweeping, inspection and maintenance of chimneys and it is the UK national trade association for sweeps, representing over 250 of them. Forgot those images of  young sweeps, just small boys,  being sent scuttling up chimneys by the fire lit beneath them, today new members of the NACS undertake compulsory training and on-site assessment.

They are also checked, prior to enrolment, for public liability insurance and to ensure they have all the necessary tools and equipment to ensure the public is well protected by the services of a professional sweep.

Given that sweeping chimneys is such an ancient profession, you might be surprised by the modern equipment many sweeps carry, including smoke generator machines and CCTV cameras to help them assess chimneys and diagnose any faults.

If you have a solid fuel fire, the NACS recommend that you have your chimney swept at least once a year; this, they say, is because all appliances, whatever fuel they burn, be that coal, wood, oil or gas, need to be able to ‘breathe’ in and out. It is for this reason that current Building Regulations, Document J, stipulates that suitable access is provided for the cleaning and inspection of flues – so you must ensure that soot doors and cleaning plates on flue pipes are incorporated into any newbuild fireplace.

As much as a chimney sweep does for the care and maintenance of your fireplace chimney, he also does far more.

Chimney sweeps double as in-home fire prevention specialists. While they are busy scrubbing away at the crud in your chimney, they are feverishly searching for any unsafe condition that can lead to a chimney fire, or unhealthy or fatal air quality. In truth, chimney sweeps don’ t just clean your chimney; they can also save your life.

With this in mind, you could do a lot worse than select your sweep from the register of the NACS and, to help you do so, they provide a useful county list of registered chimney sweeps.

The word hearth was originally used simply to describe the part of a room where the fire was made; initially constructed  simply by beating the earth to compress it. This fireplace came to be constructed from stone, brick and tiles, the earliest fires being retained in a simple shallow stone pit.

Similarly, chimney design went through a number of changes before they became something we would recognise today. The first chimneys were, in fact, simple holes in the roof that allowed the smoke to escape, thereby freeing householders from choking on it, and they tended to be confined to cooking areas and kitchens. As always, necessity was the mother of invention.

Governments and rulers have always understood that taxation on necessities is a good earner, and fire has always been a necessity, so it was that the Anglo-Saxons paid their smoke farthings to the king, unless they were deemed to be too poor to afford it. Then, in 1662, the English government levied a tax on all hearths, save those in the meanest cottages.  This 17th century tax was a profitable one and, at two shillings per hearth,  resulted in £170,000 a year flowing into the government’s coffers; it was also unpopular tax and was repealed in 1689.

From the 12th century onwards, chimneys survive in profusion, however they were so costly that only the rich could afford them, the rest of the population relied on timber smoke hoods were used to draw the smoke from the room. The wisdom of using timber to build a structure so close to an open fire is debateable. Up until this time, dwellings were simply one storey constructs; it wasn’t until masonry chimneys and fireplaces replaced the smoke hoods that ordinary houses could have more than one floor.

By the 17th century, however, chimneys had become so desirable an architectural feature that  houses were actually designed around them.  This is why, in some homes from that era, you will see that a stone chimney stack is the sole supporting structure for not just one house, but the one next door too.

It is, though, from the fire’s fittings and accoutrements that we can learn most about how life was lived.

Paul Seignac: Child Chimney Sweep in Snow, 1876

In the 18^th century, child chimney sweeps were a common sight. Such children were very small, usually boys between the ages of 4 and 7, and they were badly exploited by their employers. Employers of these young chimney sweeps liked to send children up the chimneys because they were small, yet the youngsters sometimes got stuck up the flues, which were often still hot, and many were killed in this way. In any event, all child chimney sweeps were covered in soot and suffered from the associated effects. They also endured painful sores and scratches on their skin from being confined in a small space.

Most children were employed until they became too big to enter the bottom of the chimney, and this was a godsend for these children. The tragedy is that the plight of the child chimney sweep was largely ignored in the 18^th and 19^th centuries and their misery continued for many years. William Blake graphically told of the plight of the child chimney sweep in his poem The Chimney Sweeper.

A bill was passed in Parliament in 1788, named ‘The Act for the Better Regulation of Chimney Sweepers and their Apprentices’. This ruled that chimney sweep apprentices must be 8 years or older, but this was never fully enforced, so child exploitation continued for many years after. Finally, in 1875, a law was passed that made it illegal for anyone under the age of 21 to work as a sweep – this saw the end of the child sweep, ending the miserable existence of thousands of such children.

The history of the chimney sweep continues today, with the business still thriving in the UK. However, the role of a chimney sweep has changed somewhat, in accordance with the passage of time. With the invention of central heating came a decline in the use of real fires and thus a decline in the need for chimneys – however, many homes today still have a solid fuel fire, and such chimneys need sweeping once or twice a year. Also, modern chimney sweeps will perform an inspection of a chimney before sweeping, to check for structural or safety problems – if there are any such problems, most chimney sweeps are able to put them right.

Chimney construction and repair: Nowadays, new chimneys may be added to a building simply and quickly with the invention of chimney systems. Chimney repairs include pointing of the chimneystack and relining of the flue (see below). Also, chimney specialists may remove old and unsafe chimneys.

Chimney Lining: Many old chimneys need relining, due to normal wear and tear, and there are various signs that may indicate a chimney needs relining. This includes the smell of smoke in various areas of the home and a flue that is full of soot and tar. If you are not sure whether your chimney needs relining, a chimney specialist can perform a pressure test on your chimney to check the efficiency of the flue and ascertain whether the lining does indeed need replacing. If your flue does need relining, there are many modern ways to do this with the minimum of upheaval: for example, Thermocrete is a product that relines your chimney without any building work needed.

Chimney Cowls: There are various types of chimney cowl. Bird cowls prevent birds and other small mammals gaining access to the chimney – such types of animal are drawn to chimneys because of the privacy and warmth, but they may cause a blockage in the chimney and thus bring about a build up of dangerous gasses, such as carbon monoxide. Anti-downdraught cowls prevent smoke from a fire being blown back into a room as a result of high pressure in the chimney.

Chimney Sweep: When coal is burnt, soot builds up on the inside of the chimney and if this is allowed to build up too much, the airflow within the chimney is compromised, leading to problems with draw and lighting the fire – there is even a real risk of the chimney catching fire. If you have a wood-burning stove or burn logs on your fire, there is an even greater risk of chimney fire: burning wood leaves creosote residue in the chimney, and creosote is an extremely flammable substance that needs to be periodically scraped away from the flue to prevent a dangerous build-up. A professional chimney sweep will ensure that the chimney is free from soot build-up or obstruction from another source, thus allowing a clear passage for the toxic gasses to escape. Blocked flues can cause death through carbon monoxide poisoning. If you use solid fuel, you should aim to have your chimney swept once every 12 months.

In the interests of health and safety, it is important that chimneys are adequately maintained, especially as they get older, in order for them to work as efficiently as possible. To access whichever chimney service you require, look online or in the yellow pages for specialist providers of such services.

One reason why chimneys are so tall is to increase the draw of air, thus allowing the adequate dispersion of gasses before they are released out of the chimney and into the atmosphere. The ‘stack’ or ‘chimney’ effect refers to the movement of air within and outside of structures, and this effect is driven by temperature and moisture differences – the greater the height of a structure, the more efficient the chimney/stack effect, ensuring excellent ventilation. The inside of the chimney is known as the flue, and chimney pots considerably lengthen the flue in order to improve draught.

Other components of the chimney include chimney cowls, which help to prevent backdraught (where wind blows smoke and potentially harmful gasses back into a room). The chimney cowl works by rotating and aligning itself with the blowing wind.

Caps (known as chimney caps) may be placed on chimney pots to prevent birds, squirrels, and other small mammals from gaining access to the chimney and nesting there, causing a potential blockage. Some chimney caps have a rain guard on to prevent rain from entering the chimney, and others have wire mesh attached, to stop any burning embers or debris escaping onto the roof and posing a fire risk.

Chimneys have been around since the 12^th century, and industrial chimneys appeared in the 18^th century as a consequence of the industrial revolution. Early chimneys were very basic, but their modern counterparts were much more sturdily constructed from brick and featured chimneypots to control downdraught. Today, many chimneys are redundant – many modern gas appliances come with gas vent pipes, which are simply fixed to an outside wall.

Industrial chimneys are different from a regular chimney, in that they are completely external from a commercial building. Usually placed near a boiler or furnace, noxious gasses are carried to the chimney by ductwork.