Chimney Insulation

decrrrrrr

Traditional heat insulator is a Lime/Cement/Sand mix but are there any other products out there that builders are currently using?

Cheers,

Dec

tcoen

There is a lightweight insulation called vermiculite. Most builder providers will stock it. Make sure your block layer uses it as specified by the manufacturers. I think you mix it with cement.
Schneidel and anki do whole chimney systems.

rooferPete

Hi Dec,

Vermiculite is a back fill product usually used when re-lining chimneys, due to it's cost and uses it would be unusual to find it in a standard new build chimney.

It is not unusual to find sheet insulation like aeroboard wrapped around the new type socket flue liners, Rockwool is another and most likely better material.

The need to insulate a standard build chimney would be unusual unless a large area of the chimney is outside the building leading to condensation within the flue.

Another reason could be a question mark on the flue size (diameter), the main reason for loose or mainly mortar back filling around clay flue liners is to protect the flue liner in the event of fire as the liner can crack when subject to excess heat.

The system build chimneys referred to by tcoen are very good and usually used for retrofit chimney stacks.

I fully agree with him that the manufacturers instructions must be followed to the letter when using these systems.

Some systems call for Perlite which can also be used in standard new build chimneys but not very often as part of the success of a chimney is the ability of the clay flue to expand if necessary without causing the chimney to crack inside or outside the building.

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