dimensionsInternal diameter = 126mm
External diameter = 128mm
Various lengths of flexible gas liner are available (up to 30 metres).
You can install your gas liner either from the top or bottom of the brick chimney stack. Whichever way you chose to install the liner, please ensure that you have sufficient clearance around the outside of the liner to ensure the least amount of friction, or possibility of catching any bricks within the chimney stack, does not occur.
Unpack your liner and, attaching a drawstring to the nose cone, (making sure it is long enough to reach the bottom of the stack), connect the nose cone (purchase separately) to the end of the liner using gaffer tape.
You will need two people to install your liner successfully, one at either end of the chimney stack. From the top of the roof, start to push the liner, nose cone first, down the stack. The person at the bottom of the stack should hold the string and take up the slack. Work in tandem to feed the liner down the chimney stack, ensuring you leave enough liner at the bottom to secure your adaptor and enough at the top to secure the top fixings.
Please note: The liner should not be fitted directly to the appliance. A short length of either vitreous or 316 stainless steel should be fitted from the appliance to the liner adaptor.
Download Building Regulations Document J (effective October 2010) below
(Right click link, then select "save file as..")