A gather hood is commonly installed when fitting flexible flue liner above an open fireplace. It creates a larger area for the flow of gasses to escape and pass up the chimney liner to terminate. The gatherhood is supplied with an adaptor to attach the flexible flue liner to.
The gather hood is attached to the base of the chimney and at the top of the chimney chamber, the metal flaps are folded at right angles and screwed into the brickwork.
The base size of this gather hood is 300mm x 300mm and the adaptor on the top is suitable for 175mm (7") flue liner.