Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 1/18/2017

how do we know if we need a new chimney flue liner?

How do we know if a flue chimney liner is needed for our fireplace? and is replacing a flue the same as replacing the liner?-

Do you have the same question? Follow this Question

2 Answers


Terminolgy is bandied about differently by different people and in different parts of the country, but in general terms the "flue" is the passageway up the chimney for the combustion or "flue gases", not the inner surface of it, which is the flue lining. But - many people call the "flue" the inner lining of the chimney, not the smoke passageway itself as it technically is.

In much older chimneys the flue lining or liner (the inner surface of the chimney exposed to the flue gases) was commonly just the inner course of brick or stone (or even slopped on and smoothed clay in old wood and clay chimneys, of which a few are still around and in use in predominately rurual areas), later more commonly refractory (high-temperature) cement or fire brick lining or cast iron pipe, in somewhat newer chimneys commonly a segmental concrete or clay liner or even a heavy cast iron or steel pipe lining - sometimes a troweled or cast-in place mortar or concrete lining. These are all also methods of repairing a deteriorated original flue, hence part of the confusion in terms at times.

To other people, a "liner" means a separate detached system spaced off from the existing chimney flue walls - commonly these days a lightweight stainless steel (occasionally galvanized in a few areas but that is very short-lived) metal pipe (heavier wieght in commercial sized applications or where internal strength may be needed, like in many-storied buildings). This "liner" or "metal flue duct" may be single or double walled, depending on local building code and on whether it is intended only as the first layer of heat protection (with the original chimney providing the second), or double-wall if intended to be the entire flue gas retention system. The reason for two layers in a modern "liner" is so the heat from the inner lining can escape up the chimney between the inner lining and the outer - a single lining does not provide protection against overheating of nearby combustible materials like framing if it is used alone in an otherwise unsafe chimney liner situation. Older chimneys did not use this system - hence a lot of chimney fires as chimneys got older, and allowed hot flue gases to escape through cracks or deteriorated mortar or even, with very hot fires of long duration, got the flue surface hot enough that the chimey bricks or stone heated up enough to cause combustion of the wood framing or insulation or siding behind them.

To find out what your particular situation is, you need a certified Chimney Sweep (your Search the List category) inspection - varies in cost, but rarely below $100 and generally not over $250 including cleaning, which is generally needed for him to be able to see the actual existing condition under the creosote and soot buildup (in solid fuel burning fireplaces, as opposed to gas-fired, which commonly need little or no cleaning for inspection).

If liner repair/replacement is needed (and depending on what he shows you via camera probe or such and how much repair cost is estimated), you will then want or need to discuss costs and options with a Chimney Repair (your Search the List category) contractor - your chimney sweep might or might not be affiliated with or employed by one.

Depending on chimney fuel and use and what sort of fireplace/woodstove/gas insert or stove you have, and local building code, might call for repair or replacement of a "solid lining" inside the flue, or possibly of putting in (especially with gas stoves/fireplaces put into wood burning ones or wood-stoves feeding into a chimney) a steel replacement liner, sleeved into the flue without actually bonding it to the existing chimney (except for a few centering brackets and top and bottom supports to keep it centered in the flue). The latter is commonly cheaper, but not always - all depends on what your existing system is, current building code related to that, and how easy it is to take out and replace or to repair. Double-wall insert liners are also generally used in chimneys converted to use as flues for gas or oil heating systems, because generally the existing chimney is toop large to provide for proper drafting.

I have seen clay flue replacement and cast-in-place lining jobs come in well below steel flue pipe as replacement - also (more commonly probably) vice versa, so be sure to get several repair opinions and bids. And you will have to decide if you tie the bids to a specific option, or allow different bidders to bid different options as they feel best (or maybe even allow a couple of options from any one bidder) to allow comparison between them. Obviously, as always, cheapest is not necessarily the one you should take, and be sure current code compliance is mandated in any replacement contract (in-place repairs commonly do not have to come up to current code - up to you if you demand the flue be up to current new-construction code). If going with a metal liner, unless solid heavy iron or steel pipe is required for strength, I would definitely recommend only stainless steel be used - gives you indefinite life and safety versus maybe 5-10 years before rusting seriously sets in.

You can find a number of previous questions with responses about typical inspection and liner replacement or insert liner jobs in the Home > Chimney Repair link in Browse Projects, at lower left.

Answered 3 years ago by LCD



This is Erick in Member Care. Thanks for your interest in Angie's List!

We'll be happy to help find top rated chimney repair provider to replace your chimney flue liner, but it doesn't look like you have a subscription to the List yet. You can join by visiting or by giving us a call. Our call center is available 8:00 am-9:00 pm weekdays and 8:00-5:00 pm ET on Saturdays.

Thanks for your question and we look forward to assisting you!

Answered 3 years ago by Member Services

Related Questions

Terms Of Use
Privacy Policy