Although the words are often used interchangeably, a chimney and flue are different things. The chimney is the supporting structure (what you can see on a house) and contains the flue. The flue is the interior channel that carries the products of combustion up to roof level and releases them into the atmosphere. The flue should be lined to prevent smoke or chemicals leaking through the fabric of the chimney and into the house or walls.
For homeowners needing chimney re-lining services, there are various types of flue and chimney lining available.
Modern houses tend to be built with clay liners. Clay lining is the most traditional, and is popular because it is a very cost effective method. The tiles tend to last around 50 years, after which deterioration in the mortar joints and damage to the tiles can cause leakage of flue gasses. However, it isn’t as easy to use clay tiles for chimney relining as the process requires holes to be cut through the brickwork of the chimney to access and replace the older tiles.
Stainless steel liners can be rigid or flexible, single or double skinned. They are a more expensive option, but one that usually comes with a lifetime guarantee. The advantage of a flexible stainless steel lining is that it can be passed down from the rooftop in one piece – right through the chimney and into the fireplace opening.
Ceramic lining can come in rigid sections or as a layer that is sprayed on the inside of the flue. The spray option builds up a layer thick enough to protect the chimney but thin enough to ensure a good updraught in the flue. Ceramic liners are capable of withstanding prolonged exposure to heat and are protected from the corrosion that the products of combustion can cause.
Each lining material has its pros and cons, and ultimately which is most suitable will depend on the flue and property in question. Embers will carry out a thorough inspection of your flue and home to decide which method of chimney lining will be the most effective.