Flue Liner Installation
In addition, current regulations state that all chimney flues of 12 metres or more in height must be lined before any new gas or solid fuel appliances are installed.
Grade 316 is for all standard gas, oil and solid fuel (logs, coal, anthracite etc) appliances.
Grade 904 would generally be installed for slumbering purposes – that is to say, when stoves are left slow-burning coal or anthracite overnight at a low temperature. This creates condensation, especially in the upper regions of the liner. As coal and anthracite have a high acid content, this causes corrosion in the liner and grade 904 is more resistant to this.
Gas and well seasoned logs do not have this problem.