Flexible chimney liner system design, chimney liner insulation types

There are three types of insulation for chimney liners: rockwool, chimwrap or leca.

Rockwool sleeves come in meter sections and slip over the liner as it is installed. They are easy to install and very light in weight and good where there is sufficient room in the chimney to accommodate them.

Linertherm is a very convenient and quick way to insulate your liner. A flexible sheet of linertherm is wrapped and fixed around the liner. Linertherm takes up less room than rockwool sleeves, is very fast to fit and, unlike rockwool sleeves, the liner is still relatively easy to pull and move with the Linertherm fitted.

Leca backfill insulation is used where there is not enough room to use rockwool. Small 'pebbles' are poured around the liner until the space between the outside of the chimney liner and the chimney is completely filled. Leca is a little harder to use than the rockwool sleeves and heavier too.

Vermiculite is another type of insulation very similar to Leca. We do not supply vermiculite because if there is water ingress to the chimney the vermiculite can become a soggy, compressed mass, levaing the liner partly uninsulated - this does not happen with leca.