Flexible twinwall stainless steel chimney liner is used to reline an existing masonry chimney that needs to be repaired or resized.
In the 80's and 90's fireplaces were used mostly and when the flue connected to an open fireplace was damaged, 8" or 200mm diameter flexible flue chimney liner was used to reline the chimney. The damage to the flue could have been caused where the ceramic chimney pots had cracked after the chimney caught on fire or perhaps subsidence had occured.
Gradually over time, stoves became more popular and narrow diameters became more prevalent as a smaller diameter flue is used with stoves
In Ireland today, two grades of stainless steel twinwall flexible chimney liner are widely used, 316 and 904.
316 stainless steel is designed for use with timber or fuels with a low sulphur content and higher grade 904 stainless steel is used when the fuel being burned contains a lot of sulphur or petro-based elements which makes the smoke much more corrosive - smokey coal, anthracite and poor quality smokeless fuels are in this category.
SHL supply both 316 and 904 grade stainless steel flexible flue chimney liner for solid fuel.
Should I choose 316 or 904?
The decision on which grade stainess steel liner to be installed in the chimney should be based on a few factors, namely;
1. What fuels are permitted to be burned in the heat producing appliance i.e. a stove that can only burn timber or a high quality smokess fuel such as Arigna's HETAS Approved smokeless fuel really only needs 316 grade chimney liner whereas smokey coal and anthracite needs 904.
2. If you have chosen a multi-fuel stove or insert, what kind of fuels are you planning on burning (you should ask yourself this question before you buy the appliance)? If you would like freedom to burn any solid fuel, we highly recommend 904 grade flexible flue chimney liner, if your stove limits you to timber, the point above applies.
3. How much money you want to spend on the installation. 904 twinwall flexible flue chimney liner is approximately 1.5 to 2 times as expensive as 316 twinwall flexible flue chimney liner.
4. Who will be using the stove - if for example, the dwelling is a rental property, you cannot control what the people living there will burn, therefore, it may be advisable to install 904 twinwall flexible flue chimney liner which should mitigate problems caused by tenants burning any fuel.