Flexible Chimney Liners Explained

When chimneys get old or are not maintained properly they can deteriorate and create hazardous conditions.Cracked tiles and deteriorating masonry can allow hazardous gases or even fire to enter your house. In order to remedy these situations there are two things that can be done. The entire existing chimney can be torn down and rebuilt, or you can reline your chimney with a stainless steel chimney liner . To tear down and rebuild a chimney is not a small job. It's very labor intensive and can cost quite a bit of money. Sometimes it can be next to impossible, for example if the chimney runs up through the center of the house. The easiest and most cost effective way to repair a chimney is to reline it with a stainless steel chimney liner.

Many chimneys have jogs or offsets as they rise to the top of a structure, so a rigid pipe is not always the best solution. In the event of the absense of a straight chimney a flexible chimney liner can be used. A flexible chimney liner can come in two forms. The first is a heavy flexible liner is the most common. Most light weight flexible liners are made of 316ti stainless steel.

Are you wondering what the "ti" stands for in 316ti?

The answer, titanium. It ads a bit more protection against high heat and corrosion. It's another improvement to the older 316L and cost about the same. The flexible liners are built to withstand extremely high heat, in case of a chimney fire. They last a lifetime, they have gone through extensive testing at Underwriter Laboratories and other testing agencies and have passed. UL1777

What's involved in a chimney relining job?

Installation begins with clearing any obstructions that may be inside the chimney. A probe is pulled up the chimney to make sure the chimney is clear. A thorough cleaning of the chimney is not necessary because the new liner will provide a brand new flue for the chimney. It's best to fit the liner to the appliance rather than vis-versa. The only exception would be if the chimney was being relined for a pre existing fireplace with no appliance i.e. wood stove, insert, new furnace. Sometimes the liner may need a little coaxing to get it all the way through the chimney, but its flexible nature allows for quite a bit of contorting. The liner should be insulated. This is a step that is often avoided, but should not be. An insulated chimney liner will allow for the liner to get heated properly allowing for a better draft. In order to insulate with a ceramic wool blanket you must wrap the liner before it is inserted into the chimney. You start by laying out the insulation on a flat surface. Then the stainless liner is placed in the center of the insulation. The insulation is then wrapped around the liner held in place with a adhesive spray (this step is optional). A wire mesh is then covered over the liner and insulation to help protect the insulation as its snaked down the chimney. A stainless wire is then spiraled around the mesh just to add a little more strength. The mesh is then held in place on both ends by large hose clamps.

Are all Chimney Liners the same?

No be sure the liner you purchase is 316Ti if flexible and UL rated. If rigid is used be sure it is 304L for solid fuels and 316L for any type of fuel. Do not be mislead by price, usally this indicates made in China. They vary in their steel makeup, some leaving out the Titanium. Most people are impressed with the strength of the leading manufacturer's Rockflex and Forever Flex liner. Does the liner need to be to withstand the weight of a 300lb man? No, it doesn't. When the liner is placed in your chimney there is no weight pushing on it's sides. So this is something that is not really neccessary, and is more marketing than anything else. Different companies provide different components with their liner kits. Some have clamps, some use screws, and some use a combination of clamps and screws. Transcontinental Equipment manufactures components that use a patented tab and clip system. The liner kit is very easy to install and can accomodate tight bottom termination areas.

A job only for the pros?

No, this is a job that is recommended to be done anyone handy, detailed, willing to spend a short afternoon doing it the right way as instructed in the instructions provided with the kit. A do-it-yourselfer to tackle the job.