Chimney systems

A chimney system operates in demanding conditions, particularly the part that projects above the roof. Outside, it is exposed to rain, snow, wind, heat and frost; inside, to high temperatures and flue gases. The materials used to finish the projecting section should withstand these conditions, be non-combustible, resist melting, and be highly durable and of good quality. This section should also be finished carefully and attractively to complement the roof covering and the building's style. The owner chooses the materials and colours at the design stage, but they should ensure safe use and enhance the building's appearance.

A chimney system is a permanent part of the house and should be designed to last for many years. When building it, allow not only for connecting the current heating boiler but also for connecting different boilers in future, since a boiler has a relatively short service life. Chimneys can be made from various materials to suit different needs and preferences, from traditional masonry to more modern ceramic chimney systems.

Traditional masonry chimney

This is built from clay bricks or hollow clay blocks. The section above the roof is usually built from clinker or clay bricks and faced with clinker tiles. A concrete cap on top protects it from precipitation.

Choosing the right masonry mortar and forming the joints correctly are essential. They provide a tight seal and ensure that the mortar between the bricks does not crack. The chimney can be treated with special brick and clinker impregnation products, and doing so is worthwhile. These are colourless treatments that keep the clay material clean and preserve its attractive colour for longer. You will find suitable products in the Construction chemicals section. Chimneys are often rendered, or clad in the same material as the roof, such as fibre cement tiles or slate. Prefabricated chimney tops are also available with factory finishes of brick cladding, smooth acrylic paint or textured resin render. The finishes come in several colours.

Chimney cowls can be:

• rotating – they use wind power to assist the draught; the turbine rotates in one direction, regardless of wind direction or strength, creating negative pressure in the flue;
• self-orienting – the cowl turns to face the wind; these are designed for outlets of natural-draught flues and ducts.

A traditional masonry chimney can also serve a house heated by gas or oil. Simply insert an acid-resistant stainless steel liner and connect the boiler to it. A heat-resistant steel liner, provided the opening has the correct diameter, allows an old, leaking chimney to continue carrying flue gases from solid fuels, restoring its function.

Ceramic chimney systems

These are an excellent solution for homes heated by gas or oil. The flue, usually made from stoneware, sits inside a casing of lightweight concrete blocks. Mineral wool between the walls of the block provides thermal insulation for the whole system. The blocks can have one channel, a single smoke flue or several channels used as ventilation ducts. A concrete cap finishes the top, while the part above the roof can be finished with various materials, such as clinker façade tiles.

A house may have one or several chimneys, depending on its architectural design. All the flues and ducts – for gas or oil combustion, smoke and ventilation – are usually housed in one chimney. Most importantly, every heated and ventilated room should have its own separate flue and ventilation duct.

Flue and duct insulation

The building's proper operation and safety depend on the technical condition of the flues and ducts. Blockages or structural defects in combustion and smoke flues can increase energy consumption, reduce heating efficiency and damage walls and chimney system equipment. They can also threaten fire safety and put occupants at risk of carbon monoxide poisoning. Building law sets out the requirements for these structures, the procedures for the technical acceptance of buildings, and the requirement for supervision and regular checks by chimney professionals.

Chimney system performance depends on the design of its flues and ducts, the weather, the local topography and the chimney height. For correct operation, the following protection and insulation are needed:

• gas-tight sealing – the entire surfaces of the channels, particularly combustion and smoke flues, must be hermetically sealed;
• thermal insulation – the insulating materials must protect the walls from the damaging effects of high temperatures;
• fire insulation – it must protect against fires in soot deposited on flue walls and prevent fire from spreading beyond the flues;
• chemical protection – it protects the structure against corrosion and the damaging effects of acidic sulphur compounds formed during combustion;
• waterproofing – it protects building elements against moisture damage;
• sound insulation – it dampens vibrations arising in the combustion chambers of large gas boilers;
• outlet protection (cowl) – it guards against adverse weather: precipitation, large temperature fluctuations and wind.

Ambit's specialists can provide detailed advice on chimney system insulation. For basic information on thermal insulation, see the Insulation, mineral wool section.

For a chimney to work properly, every component must be correctly installed. By drawing on our specialists' experience, you can be confident that it will be built entirely from certified materials, be safe and perform its function for many years.

Chimney system manufacturers

The Polish market offers a wide choice of products from many manufacturers. Our range includes the best products from leading companies:

• Schiedel
• Presto

Every chimney system offered by Ambit comes with a long-term warranty. Our knowledgeable, experienced specialists will be happy to help you choose the best solution, answer your questions and provide professional advice, so you can make the right purchase.

Chimney systems:
Schiedel:

• Rondo Plus
• Rondo
• Quadro
• Avant
• Multi
• Pro Advance
• Ventilation blocks

Presto:

• Uniwersal
• Duo
• SPS
• Ventilation blocks