Alufol chimney inserts have been designed to provide protection the inside of chimney ducts against the aggressive influence of extracted combustion gases of natural gas of temperatures up to 160°C. It is also perfectly adapted to seal ventilation ducts. The Alufol insert is to be used in all houses, public, industrial and other buildings independently of the shape of a combustion gas extraction or ventilation duct. The insert copies exactly the shape of a chimney duct, which is why using the Alufol method enables you to maintain the cross-section of an existing combustion gas extracting or ventilation duct. The great advantage of using Alufol inserts is the possibility of using them in chimney ducts having local curvature and contractions thus avoiding construction work made inside buildings that are arduous for occupants such as forging, punching or rebuilding. Alufol are of no use in smoke ducts from fireplaces and other solid fuel-fired devices.

Alufol inserts are made in the following dimensions:

• A chimney duct of up to 60 cm of perimeter (e.g. 140x140, 150x150, ø150 cross-sections)
• A chimney duct of up to 90 cm of perimeter (e.g. 140x270 cross-section)
• A chimney duct of up to 120 cm of perimeter (e.g. 270x270 cross-section)
• A chimney duct of up to 150 cm of perimeter
• A chimney duct of up to 180 cm of perimeter
  

The maximum length of an Alufol insert is 40 running metres. The insert is acid-, gas- and waterproof, chemically inactive, unabsorbable, appropriately abrasive resistant except with steel strings and brushes. The smooth surface of the insert increases significantly the stack effect. The life of an Alufol insert has been determined on the basis of research and tests as at least 20 years. Installation of the insert takes approx. one hour and eliminates all arduous constructional work connected with reconstruction and repair of chimneys made according to traditional systems. The Alufol insert is installed through the outlet of the chimney cap, down to the cleaning hole and it is stretched within chimney duct by means of compressed air.