Flues & Accessories FAQs

When you’re choosing flues, the type of steel makes a big difference. Picking the right grade means you’ll get a product that lasts longer and gives you better value. Of the three grades most often used for flues, we stock and supply 304 and 316, as they offer the best durability and resistance to heat and corrosion.

304 Grade Stainless Steel (304SS)

This is our most popular option and works well for most installations. It has excellent anti-corrosion properties, which is especially important with closed combustion fireplaces where weak acids form during burning. These acids eat away at the inner walls of flue pipes, but 304SS will usually last about twice as long as 430SS in these conditions. It’s also non-magnetic and offers great value for money.

316 Grade Stainless Steel (316SS) 

This is the top of the range. Non-magnetic and more expensive, it’s often called “Marine Grade Stainless Steel” because it’s used on boats and ships. That makes it perfect for coastal homes where sea spray and salty air can take their toll. We can supply 316SS flues by special order.

430 Grade Stainless Steel (430SS) 

This is the entry-level option and the only one that’s magnetic. Because it doesn’t contain Nickel, it’s less resistant to heat changes and corrodes more quickly. It’s inexpensive but won’t last as long as 304SS or 316SS, and it tends to rust easily.

Whichever grade you choose, all stainless steel flues need regular cleaning and maintenance, especially if you live near the coast.

It’s quite easy to tell the difference between a single-skin flue and an insulated double-skin flue. An insulated flue is made up of two plain flue pipes, one inside the other, with insulation packed between them. Because of this design, an insulated flue has a larger diameter than a plain flue.

The insulation helps in two important ways. First, it keeps the outside of the double-skin flue cooler than a single-skin pipe. Second, it reduces the amount of condensation that builds up inside the flue. Together, these benefits create a smoother, more efficient passage for smoke to exit through your flue system.

A proper flue kit should include insulated and plain flue pipes, which is the industry standard. The part that links the plain pipe to the insulated pipe is called an insulated “end-cap.” This piece is usually installed about 300 mm below ceiling level and continues through the roof space.

We use insulated flue pipes where the flue passes through the ceiling and roof because single-skin flues get very hot. Inside the room, single-skin flues help heat your home and act as an extension of the fireplace. Once the flue goes through the ceiling and roof, however, an insulated pipe is the safer choice. Double-skin flues only become warm on the outside, which protects your waterproofing from expanding and contracting with each heat cycle. Insulation also slows the cooling of smoke, which greatly reduces condensation inside the pipe. For this reason, insulated flues are the preferred and safer option once the pipe leaves the heated room.

The standard material is anti-corrosive 304 stainless steel, ensuring many years of safe fireplace use. 

All our specials include the European CE-certified Atritube flue system imported from Greece. Atritube flues are made from superior 0.4 mm thick, 304 grade stainless steel, designed to resist the harsh chemicals found in the gases of closed combustion fireplaces. They are seam-welded and assembled with clamps, avoiding drilling and pop riveting.

Over time, all stainless steel flues will naturally discolour due to a chemical reaction with oxygen and fireplace heat. This creates unique “living art” in your home, with colours ranging from golden to amber, purple, and even blue, depending on how hot your fireplace runs.

If you’d prefer a different look, you can have your flues sprayed in the same colour as your fireplace, such as black, anthracite grey, or ivory. This service is available at an additional cost and must be pre-ordered with your fireplace. Just let us know when you request a quote.

When a fireplace is connected to a plain flue that runs outside the house, there’s a much bigger temperature difference between the hot air inside the pipe and the cooler air outside. As the flue gases cool, this creates a large amount of condensation and soot inside the pipe. Over time, this shortens the lifespan of the flue because corrosion sets in, and the condensate collector can’t keep up with the excess moisture.

Insulated flues are more expensive, but they last much longer and meet European installation standards. For this type of setup, we always recommend insulated flues as the safer and more durable choice.

No, plain flues cannot be installed through a ceiling because it goes against Fire and Safety Regulations. It would also mean your insurance will not cover you in the event of a fire. For safety reasons, we always use insulated flues for the section that passes through the ceiling, the roof space, and above the roof itself.

In most cases, the flue will also need to be replaced. This is usually because the old flue is a different size to what your new fireplace requires, or it may already be in poor condition. We’ll advise you on the best options, and if parts of the old flue can be safely reused, we’ll take that into account.

It’s also important not to mix different types of steel, as this can speed up corrosion. We use 304 grade stainless steel flues as standard, since they offer excellent resistance to rust and corrosion.

It’s usually best to replace the entire flue rather than only a few parts. Older flues are often in poor condition, and by starting fresh, you’ll have a complete, reliable installation that won’t need further work any time soon.

That said, we’ll always advise you on your options, and if certain sections of the old flue can be safely reused, we’ll take that into account. It’s also important not to mix different types of steel, as this can increase the risk of corrosion. As standard, we use 304 grade stainless steel flues, which are highly resistant to rust and corrosion.

The best flue pathway is always straight up, as this gives you the strongest draw. If you need to work around a beam, roof section, or wall, the flue can run at a diagonal angle, but the horizontal distance should not be more than 0.5 metres. Anything longer than this reduces the draw, causes smoke to flow back into the room, and interferes with the proper functioning of the fireplace.

Yes, absolutely, but this needs to be ordered in advance. We have a dedicated spray booth and skilled staff who handle the process. The service is charged per item sprayed, and flues must be pre-ordered when you purchase your fireplace. That gives us time to prepare, spray, and bake the paint onto the flues.

Our standard colours are black, grey, and ivory-cream. For Charnwood fireplaces and flues, you can also choose from an extended colour range that we import specially for this brand.

A tempered glass floor plate protects your floor from the heat of your fireplace. It allows for traditional open or closed combustion fireplaces to be installed on wooden, laminate and carpeted flooring.

Tempered glass is a type of toughened, safety glass processed through controlled thermal or chemical treatments. The tempering process puts the outer surface of the glass into compression and the inner surfaces into tension. The result is tempered glass with far more strength than normal glass. Fully tempered glass can take on a higher load and is four to six times stronger than double glazed glass, so it can take the weight of your fireplace. This type of glass is used when safety, thermal resistance and strength are important considerations.  Should the glass break, it crumbles into small granular chunks rather than splintering into jagged shards. Please be aware that in the event that you drop a hard object on to the glass, you may still crack or chip the finish even though the glass is tempered.

The building regulations in South Africa stipulate that you are required to utilise a fire hearth if your flooring material near to your fireplace is of a combustible nature.  The regulations are designed for all fireplaces including closed combustion and traditional open fire places. The hearth must be of ‘adequate thickness and of an incombustible material’ (SANS 10400: v2010). It is therefore compulsory to have a floor plate if your floor is covered by a material that is not fire proof, for example wood, carpets or melamine.

The floor plate should stick out at least 5-10 cm on each side of your fireplace when it stands on top of the floor plate. Ideally you’d want about 50 cm – 70 cm of floor plate in front of your fireplace to catch any accidental spills of hot material. Keep in mind that we install between 15 and 20cm off the wall, so add the fireplace depth to this and add the overlap measurement in front.

Our floor plates come as standard rectangles with a bevelled lip. However you can custom order them from us in any shape and size. You can choose between a glass (12mm thickness) and plate steel (2mm thickness) floor plate. Keep in mind that custom orders have a minimum 2 week lead time.

The black glass has a black solid-coloured underside and features a high gloss finish. The clear glass allows for an unobstructed view of your beautiful wooden or marble flooring and won’t detract attention away from your fireplace or clash with your colour scheme. We seal the edge of this floor plate with silicone, thereby sealing out dust and dirt, so that it always remains clean on the underside. Glass floor plates allow for natural light reflection and ambience. The black steel floorplate has a black matt, solid-coloured finish and is a cost effective option if you are not using glass. Perfect for a more traditional look and style.

You could also choose to go with your own floorplate like stone, marble or granite. Please enquire about recommended sizes suitable for your fireplace.

Well, this depends on what size your fireplace is. A floor plate should have about 5-10cm on either side of the fireplace, have 15cm behind the fireplace, cover the depth of the fireplace, have and it should overlap 30-40cm in front of the fireplace. A large fireplace would use a large floor plate. We also offer custom floor plate sizes for our clients, but they have to be ‘special pre-ordered’ and may take longer. The floor plate should be installed with the fireplace.

We use an EPDM Flashing combined with silicon and Megabond roof sealant (with waterproofing fibre in it) for reliable waterproofing where the flue exits your roof. EPDM’s are suitable to use with most insulated & non-insulated flues. The EPDM has a rubber boot that allow for a small amount of movement in the flue caused by wind and heat expansion. With old fashioned ‘pap-en-lap’ a waterproofing membrane (fibre material) is used in layers with lap cement or acrylic waterproofing which is painted on. The process is time consuming and messy, and any movement causes the waterproofing seal to break, which results in leaking. With EPMD’s we have found that our waterproofing is watertight. Our waterproofing is guaranteed for 18 months after the installation date.

Wood pellet are used to fuel pellet burning fireplaces for residential heating and to fuel large boilers, they offer excellent combustion efficiency.

They are an extremely eco-friendly, natural and green fuel that’s produced without additives from 100% biological materials and wood processing waste. Most pellets are produced from offcuts from the timber industry, although some wood is sourced from sustainable forestry plantations and the clearing of alien vegetation. This waste is compressed at a very high pressure and compacted into small, 6 to 12 mm diameter cylinders which resemble ‘rabbit feed’.

Pellets burn more efficiently than other wood forms because the binding process reduces the moisture within the wood to less than 10%, which is 20% less than the average log of wood. Using pellets also reduces harmful carbon emissions when compared with other fuel sources. They are a carbon neutral product, because the combustion process used to create energy generates no increased greenhouse gas emissions. They take up very little storage space and are a cost effective option to heat your home.

You may be hearing:

• A banging sound when the wind is gusting and howling.
• A sound like a metal bin being thrown down a gravel road.
• A rushing noise with moderate wind.
• A gentle humming noise with very strong wind.
• A whistling, flute like noise that goes away when the door is opened.
• A sound like “blowing-across-the-top-of-a-bottle” with the air inside the flue vibrating like an organ pipe.
• A noise is that is amplified in the chimney.
• A very ‘loud, roaring freight train’ (this particular noise could be a chimney fire).

Causes and possible solutions:

• Animal invaders such as birds clear out once you’ve removed their nests.
• Clicks, cracks, clangs and dongs are often caused by the thermal expansion due to heat, and these sounds are normal.
• If your chimney has no cowl, it could be the wind blowing over the top of the chimney.
• It could be a damaged, stuck or loose cowl, or a damaged chimney flue.
  It could be that you need to secure the loose flue lining in the chimney (which is banging against the chimney wall) with brackets or expanding heat resistant foam.
• The wind blowing across the chimney top maybe pulling more air up and out, causing an increased draft up the flue which creates noise. Here you could try installing a stainless steel ‘fixed type’ of chimney cowl with louvres on each of the square sides called a Turbo cowl. It diverts the wind upwards and away from the top of the chimney.
• A cowl that turns away from the wind will prevent air blowing over the chimney and therefore prevent the noise, but it’s often not a good choice in very high wind areas. However, you could install a storm cowl which is better suited to windy areas.
  Structures like trees and buildings close by may cause wind turbulence, you may have to extend your flue higher.
• When you hear a ‘flute’ like noise that goes away when the fireplace door is opened, you could open the vent sliders in small increments until the noise goes away. Installing a damper which shuts off or restricts the air flow up the chimney may also help.
• A chimney fire sounds like a loud, roaring freight train. If you suspect a chimney fire, close all the air intakes and chimney dampers to suffocate the fire. Exit the building immediately and call the fire department from outdoors.
• Unfortunately there is not much that can be done to fix noise problems if you live in a high wind area. The wind-noise within a chimney will be intermittent and will depend on the wind and weather conditions. Under safe operation and with regular maintenance of your closed combustion fireplace, it is normal to feel the wind vibrating within the flu. The suggested solutions above may help you. You are welcome to contact us for further advice.

There are no certainties when it comes to smoking closed combustion fireplaces and a number of reasons why they could be smoking.

Dry, seasoned, hard wood weathered from the year before is the best to burn in your fireplace. Dry blue gum is great. Black wattle is ok, but burns up quicker.

Your wood is more than likely wet, as any wood sold during winter is wet. Space the wood for ventilation, use smaller pieces of wood to get the fire going (vents open all the way) and use lots of blitz. Add 2 logs when the small bits are blazing and close your vents by 2/3rds when the logs are burning well. The warmer the chimney and fireplace gets the better the air pull or draft up the chimney.

A chimney clean may be required. A build-up of creosote in the flue can cause smoking, and it can cause chimney fires. A bird’s nest can also be a problem. GC Fires offers annual chimney sweeping from November through to March. The fire rope sealing the door may need replacing. Check that the wood you stored in a the ‘decorative compartment’ of the fireplace is not smouldering.

Ensure you are not causing back drafts down your chimney by using extraction fans in the kitchen, leaving windows open etc. You want the smoke to pull up the chimney, and not into your house.

If your braai or open hearth is smoking, then you need a chimney sweep. The fireplace may not be deep enough, and you may require brickwork. You could try putting the coal cradle on bricks to raise the fire closer to the chimney opening at the top (worked at my last house).

A cowl could help with drawing the smoke up the chimney, but it’s not a guarantee. Your flue piping or chimney may not be high enough resulting in the airflow being obstructed by the roof apex or another structure on the roof. This can also happen when you live up against the mountain. Check your roof space to ensure that the chimney is intact. You don’t want sparks coming through the broken brickwork into your roof space and causing a fire.

Start with dry wood, as this seems to be the number one cause of a smoking fireplace (especially in winter when they sell you wood and swear that is dry).

This is rather annoying when it happens, but the solution is rather simple.

It’s usually the result of soot build up, indicating that the fuel being used in the fireplace is not burning completely. Ensure that the dampers /air controls on your fireplace remain open until the fire is well established, as this will give the fire enough air to ensure complete combustion of fuels. Adequate dry and well-seasoned kindling and fuel must be used to start and maintain the fire, and to ensure the most efficient burn possible. The chimney should be unobstructed and clean, as this allows the smoke that is produced to escape. Empty the ash pan often.

The easiest way to clean it is by using a commercially-prepared cleanser such as Limpio Cleaner. Only use a product that has been designed specifically for fireplace use or you could end up with glass discolouration. Alternatively you can clean the glass window by dipping the damp end of a cloth into the cold, white ash left over from your previous fire & gently clean the inside of the window to remove the soot build-up. However, this option takes more time and can be messy.

With either choice, you should scrub the glass using small circular strokes.
Allow the glass to dry, and then buff it with a clean cloth.

GC Fires stocks Stove & Grate polish, and fireplace glass cleaner.

Fireplaces require occasional TLC, but only when they are completely cooled down.

Clean the outer surfaces of the fireplace with a soft, dry cloth. Don’t use abrasive cleaning materials.

Clean the glass window by using a commercially-prepared cleanser such as Limpio Cleaner or one that is recommended to you by your supplier. Only use a product that has been designed specifically for fireplace use or you could end up with glass discolouration. Alternatively you can clean the glass window by dipping the damp end of a cloth into the cold, white ash left over from your previous fire & gently clean the inside of the window to remove the soot build-up. However this option takes more time and can be messy. With either choice, you should scrub the glass using small circular strokes. Allow the glass to dry, and then buff it with a clean cloth.

GC Fires stocks Stove & Grate polish, and fireplace glass cleaner.

An annual chimney sweep can be booked with GC Fires between November & March to clean out creosote & carbon build up in your fireplace, chimney & flue. It’s best not to leave your maintenance too late, as often this creates problems.

The vermiculite firebricks in some models are replacement items & they will crack. This doesn’t affect the fireplace & they only need to be replaced when they crumble. There is no guarantee on the paint, glass and fire rope and often not on the grate or ash pan either.

All stainless steel flues turn coppery overtime ‘like living art’ & this adds to their aesthetic value. This is a natural process and can’t be avoided. If you clean your flues, do a test patch on the back of the flue out of ‘eye sight’, as some cleaning products may remove this copper colouring as well. Alternatively, you can have your flues sprayed the same colour as your fireplace. Place your order with your fireplace, before we install.

You’ve just finished braaiing a beautiful piece of steak and take the first bite, but it tastes a bit gritty ….….could it be the spices, or sand…….or could it be soot from your chimney?

How often you clean your chimney varies on how often you use your chimney or fireplace, and what kind of wood you use. If you use your chimney often, you may need to clean it about once a year. If you use your chimney rarely, you still need to clean it at least once every two years. It is always easiest to hire a professional to clean your chimney; however, if you choose to clean it yourself, be sure to get sound directions and follow them closely.

We provide an excellent and professional service, using equipment imported from the Europe.

The real function of the chimney and flue is to carry toxic smoke and gas safely out of your home.  A clean chimney helps your household air stay breathable, especially with the high incidence of Asthma and Bronchial problems occurring today. Creosote and soot build-up is the main reason for cleaning a chimney. A chimney fire can result if the buildup of creosote and carbon on the inside surface of your flues ignites.

The extremely high temperature of a chimney fire can damage the chimney.  Heat warps metal chimneys, and cracks the tile liner on masonry chimneys.  If you don’t repair cracks and holes in the flue, the sparks generated by the fire in the fireplace could go through these openings into the attic or the framework surrounding the chimney.  This could cause a serious house fire.