You do not need to insulate the liner when using aluminum gas vent pipe.
Does a chimney liner need to be insulated.
Not only this but it will also stop condensation from forming on the liner and it can also increase upward speed of the flue gases which also helps to increase the efficiency of your fireplace.
Do not use standard fiberglass insulation.
Having 1 2 thick insulation will maintain your liner to the ul1777 standard.
There are different types of chimney liners which you can use to line your chimney.
The warmer your flu the better the draft and the less chance of creasote build up.
The air between the liner and the chimney wall will insulate the liner air is a good insulator although the liner obviously touches a cold wall in many places.
This will add to the diameter of the chimney liner so this route is not always practical.
When you are converting your wood burning fireplace to a gas burning fireplace and using the existing chimney as a vent it is a good idea to install a flexible aluminum liner.
If your chimney is located on an outside wall insulation added around the liner will help keep the flue gases warmer.
The blanket will get wrapped around the chimney liner the entire length.
Cast in place chimney liners are lightweight cement like products that are installed inside the chimney forming a smooth seamless insulated passageway for the flue gasses.
They can improve the structural integrity of aging chimneys and are permanent liners suitable for all fuels.
The insulation will enable the flue to heat up more quickly and this increases your draft reduces creosote making it easier to clean and makes your system more efficient safer.
Chimney liners do not always need to be insulated.
On an exterior chimney you will definitely benefit by insulating a flexible chimney.
There is no building regulation that says you must insulate around a flexible flue liner within a chimney stack.
The most user friendly chimney liner insulation is the insulation blanket.
It is always a good idea to insulate your flexible chimney liner.
When installing a new liner for your heating appliance whether it is a furnace hot water heater wood burning insert or stove or existing fireplace consider insulating the liner.
Although some love the look of an exterior chimney any knowledgeable mason will tell that an interior chimney is best.
If you have a tight flue and are unable to use the blanket.
Otherwise it is not necessary especially if the majority of the chimney is internal within the building.
Chimney liner insulation offers many benefits in terms of improved system safety increased efficiency and reduced maintenance cost and in just a short period of time could pay for itself.
However building regulations do state that gases must be safely taken away from the building and by insulating your flexible flue liner within the chimney cavity will ensure that the gases will travel directly up from the stove and out through the chimney top.