Fireplace Facts

Two things we always like to know from our customers when they come to visit us is what size is your existing fireplace and what type or flue or chimney do you have? The menu above gives some short guides to help you and explains some other facts and terms we commonly use when talking about fireplaces.

Measuring Your Existing Fire

Apart from finding out what type of flue you have we will also require you to provide us with some measurements of your existing fireplace Measure the width and depth of the chimney breast (the wall that juts into the room and contains the chimney/flue). Sometimes this could be on the outside of your house.

Measure the fire opening. Height, width and depth. Does it taper in as it goes back into the fire opening or is it square hole? Please have these measurements when you contact us so that we can give you an accurate quote and tell you what is suitable for your fireplace.
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Flues

The type of chimney or flue you have usually dictates your choice of fire. To help you understand which fires are suitable for your home, please use the following information and pictures to identify your chimney. Don’t worry, if you don’t have a chimney though, you can still find the perfect fire for your home! Once you have identified your chimney (or confirmed you do not have one), take a note before you come to visit us.

Brick/Stone Chimney(Class 1)
Conventional chimneys are easily recognizable. The stack rises well above the roofline and is topped by a traditional chimney pot or gas terminal. This type of chimney relies on the natural circulation of heated air to expel the products of combustion up your chimney.

Pre Fabricated Flues(Class 2 and occasionaly Class 1)
You will see a metal flue cowl on your roof. Some are all metal whilst others may terminate through a short rectangular pot (but without a chimney stack). These flues create the same circulation of heated air as a brick or stone chimney.

Pre-cast Flue (Class 2)
Many modern homes have been built with such flues. You can readily identify them by either a metal flue cowl or a raised ridge terminal on your roof. Again, the natural circulation of heated air expels the products of combustion. Incidentally, these flues tend to be very shallow in depth so a slimmer fire is often required. Deep appliances, however, may be able to be installed with the use of either a spacer kit or deeper rebate on the fireplace.

Balanced Flue (No chimney required)
Balanced flues work in conjunction with glass fronted gas fires. The appliance is completely sealed from the room into which it is installed (so there are no draughts and heating efficiency is increased!) and a twin-wall pipe vents directly to an outside wall.

Air for combustion is drawn in through the outer pipe whilst the inner pipe removes the combustion gases to the exterior of the property.

Depending on the fire selected, the twin-walled pipe may exit horizontally through an external wall or vertically through the roof. No electric supply is required; therefore there is no sound with this flue system.

Powered Flue (No chimney required)
A Powered Flue fire is an open fronted gas appliance with an electronically driven fan system mounted directly behind it on an external wall. When the fire is ignited the fan switches on automatically, expelling the products of combustion through a short, horizontal metal
flue to the outdoors.

Electric Fires (No chimney required)

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Fires

More info to come on this.
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Air Vents For Fires

Lining Old Chimneys

The most appealing focal point in any room must be the fireplace.  Be it an open fire, closed stove or roomheater, the leaping flames and glowing coals are the real heart of the home.

However, for any fire to work successfully, it must be connected to a sound chimney and correctly sized flue. The functions of a chimney are to safely remove the products of combustion from the fireplace or appliance to outside without causing danger to the occupants of the house or setting the house itself on fire.  A chimney works because hot air rises and always moves from high to low pressure.  Factors such as running the appliance at a very slow rate or cold air leaking into the flue, will cool the gasses and affect the performance of the chimney.  To keep the flue gasses warm, consideration must be given to the insulation value of the lining system chosen.

In houses built since the introduction of the 1965 Building Regulations, all flues must be built with liners during their construction.  This is usually done with clay liners, which should last the life of the building.  However, in houses built prior to 1965, lining was less common.  Flues were usually “parged” (rendered) on the inside with lime mortar.  This parging suffers attack from acids and tars produced during combustion, and gradually deteriorates.  The flue is then in poor condition, often leaking fumes or tars into the walls or other parts of the building.  Sadly, many houses built since 1965 suffer similar problems due to badly installed flue liners and need further attention.

There are a number of reasons why an old chimney may need lining.

1. The flue is leaking smoke and fumes into other rooms or parts of the building.

2.  Condensates or tar are seeping through the chimney walls causing staining, either inside or outside the building (a common problem with wood burning stoves)

3. The flue is much too large for the type of fire or appliance being used.

4. The flue is too cold, particularly if on an outside wall, and is not drawing properly.

5. If the chimney was built since 1965, but with the liners fitted the wrong way up, tar and condensate leakage may occur.

6. The old flue surface is eroded and rough, causing frictional resistance to the flow of the gasses resulting in poor updraught.
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HETAS And CORGI