Concrete flue liners

When considering the construction of a chimney for use with solid fuels, it is important to firstly establish the size of fireplace opening you require. From this the flue liner size can be specified.

The table below gives an indication as to the size of flue liner required, relative to the size of fireplace opening. Specifically, the internal cross-sectional area of the flue lining should be 15% of the cross-sectional area of the finished fireplace opening. The fireplace and flue system can then be constructed in accordance with approved Building Regulations.

Fireplace Opening Width (mm)	Fireplace Opening Height (mm)	Flue Size	Cross-sectional area mm² of flue
500	550	200 x 200mm int. square liners225mm int. dia. circular liners	40,000 39,761
700	600	250 x 250mm int. square liners	62,500
800	600	300mm int. dia. circular liners	70,686
1000	600	300 x 300 int. square liners	90,000
1200	750	435 x 310mm int. rectangular liners	134,850
1400	800	545 x 310mm int. rectangular liners	168,950

Typical Flue Constructions

200 x 200mm int. Square	225mm int. dia. Circular	250 x 250mm int. Square
300mm int. dia. Circular	300 x 300mm int. Square	435 x 310mm int. Rectangular

545 x 310mm int. Rectangular

Approved Document 'J' (ADJ)

Red Bank’s range of concrete flue liners are manufactured in accordance with BS EN 1857 ‘Chimneys - Components - Concrete Flue Liners’ as required under ADJ ‘Combustion Appliances and Fuel Storage Systems’. A chimney flue system correctly constructed using such components will attain Building Regulations approval.