What is Chimney Lining?

A Chimney is made to safely remove the smoke from a fireplace or stove to the outside of a building, without causing danger to the people who live there.


A chimney works well because hot air rises and moves from high to low pressure. 


Chimney gasses need to remain hot so that they can stay as a gas and rise. 
Things like running a stove at a very slow rate or cold air leaking into the flue will cool the gases and this will affect how the chimney performs. 


Flexible liner and other methods of lining chimneys are designed to replace the flue in an existing chimney, The diameter of liner used will depend on the requirements of the appliance.


You may add insulation or this might be already intergrated into a flue system to improve the efficiency of the draught. This is a particular requirement for external situations. 


There are various methods and materials suitable for lining chimneys.


Chimneys with existing flues can be relined in several different ways. These 
include:


1.  Using rigid sections of clay, pumice or refractory liner installed by cutting 
into the chimney wall or by lowering sections down from the top of the 
stack and infilling with an insulating material.


2.  Insulating concrete, pumped in and around an inflatable former by a 
specialist contractor.


3.  Stainless steel flexible liner in a continuous length lowered down the 
chimney.


4.   Spray on coating by a specialist contractor.


5.   Ceramic coating by a specialist contractor.


The suitability of any of these methods of lining is dependent on each 
individual system. You should seek professional advice on what is the most 
appropriate solution for your need.




Why Line Chimneys?


Chimneys should be lined for a number of safety related reasons. 

New chimneys may require relining depending on the suitability of the current system, However systems built before 1965 will usually require a modern lining solution for the following reasons:


1. The flue walls may have broken down and can leak smoke into the room or other parts of the building, or if terraced or semi detached into the next building.


2.  Condensates or tar can seep through chimney walls causing staining, inside or outside of the building.


3. Lining with added insulation improves the operation of appliance and flue (particularity important when the chimney is on an external wall). Because flue gasses must be warm to rise.

4. Old flue systems may be worn and rough. This can cause frictional resistance to the flow of the gases resulting in poor updraught.


5. Large flues (over 200mm) particularly ones containing voids may affect appliance performance as gasses may cool and set before they can be expelled from the void.


It is important to follow the manufacturers advice on the correct size of flue to use with your appliance.


Before having a liner installed in your chimney,you should have it swept to remove soot and tar deposits by a professional chimney sweep. 


For those that already have a chimney lining, a competent sweep will be able to inspect for the following faults:


1.   Liners fitted the wrong way up
2.   Out of line or overlapping liner
3.   Obstructive ledges hindering updraught
4.   Protruding cement at joints
5.   Liner removed during previous service work or installation
6.   Damage through incorrect sweeping 
7.   Masonry damaging the liner
8.   Blocked terminal (cowl or rain cap)


These faults can lead to a number of problems with the operation of a solid fuel appliance. 


More importantly, faults with chimney lining can pose a risk to the safety of everyone in the house and should be rectified immediately.


Safety First! Always ensure that you have a working carbon monoxide detector fitted in any room where a solid fuel applince is installed and that you test this regularly.


For a HETAS registered stove installation service, advice on your stove and chimney requirements or to book a free stove installation survey throughout Cheshire, Wirral and North Wales including Anglesey, Conwy, Denbighshire, Flintshire, Mold,Wrexham and surrounding areas call us on 01745 822344. or email northwalesstovesltd@gmail.com