To line or not to line?

Hello and welcome to our next blog, today I will be looking into a question that has been asked of us on an almost daily basis, which is often difficult to answer quickly. The question is “Should I line my chimney?” and the answer will hopefully become clearer below.

First and foremost it is important to note that there are multiple factors that will affect the necessity to line your chimney stack, and that there may be more than one option available to you based on the chimney type you have and the appliance you intend to install, whether it is a wood burning, multifuel or gas stove, or a simple open fire basket each installation will be different and will require a different approach.

In this blog I will be focusing on the most popular option, and the most common situation that our own Hetas engineers encounter whilst carrying out chimney surveys, which is the installation of a new stainless steel flexible chimney liner into an existing brick built chimney connecting directly onto a wood burning or multifuel stove.

Before committing to the purchase of your new stove it is advisable to organize a home survey to be carried out by a competent chimney engineer, this can be either a registered member of the National Association of Chimney Engineers (NACE) or preferably a Hetas registered engineer, who will also be capable of offering a complete installation survey for you should one be required.

If on inspection the chimney stack is found to contain a clay or pumice lining already in situ a smoke test should then be carried out to check for any potential leaks, if the chimney fails this test then provisions should be made to install a stainless steel flexible liner or if it is feasible to have the leak/s repaired this may also be an option.

It is sometimes possible for customers to carry out a basic inspection of the chimney themselves to establish whether a clay or pumice liner is present, to do this simply look up your chimney through your fireplace chamber opening using a torch and you should see either bare brick (unlined) or a smooth clay which is a clay chimney lining. (Please see images above for reference).

If after carrying out a smoke test your clay chimney liner does pass and is considered sound and suitable for use, then the installation of your new stove should be quite straight forward. Quite typically the only parts involved in the fitting process will be a length of vitreous enamelled flue pipe directly from the stove which is then cemented into the stove collar using a product called fire cement. From the top of the vitreous enamelled flue pipe you can then install either a product called a “clay pot adaptor” or a “sump adaptor”, which are both purpose built for the task and are made from stainless steel.

Once a tight seal has been made connecting either the clay pot adaptor or sump adaptor onto your clay pot chimney liner, you may then wish to install a solid fuel bird guard cowling. There are an abundance of different suitable cowls on the market, although the product we tend to recommend in our showroom and sales line is the stainless steel Wind Jammer cowl. This cowl is designed to not only prevent rain, birds and other vermin from entering the chimney, but it also aids the chimney draw to help prevent smoke passing back into the room through the stove.

The Wind Jammer cowl is available in a powder coated red finish as standard, and can be easily fitted onto a standard chimney pot using the supplied fixings using a screwdriver (no drilling is required).

Should a smoke test be carried out on the chimney which fails then a stainless steel flexible chimney liner will need to be installed. The process of lining the chimney is usually quite straightforward although it is advisable to employ the services of a qualified engineer to carry out the work as these engineers will also provide the relevant certification for the installation.

In our next Blog I will be continuing our discussion on chimney lining with a step by step “How To” installation guide, which I hope will be useful to anyone considering installing a chimney liner and stove themselves. This guide will also offer customers a better understanding of the work that their chosen competent installer is carrying out for those choosing to have a professional complete the stove installation.

To find your local Hetas registered installer please visit the official website at, you will then be able to click the “Find Installer” button and enter your postcode for a list of your closest qualified engineers, most of which should offer a free, no obligation home chimney survey. Alternatively if you are in the Essex, Kent or London area why not email us at [email protected] or call on 01621 772221 (Option 1) to arrange a free survey.

Thank you for reading, all Likes, Comments and Shares are greatly appreciated!



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