Vermiculite is Fireproof material and used in mixed or dry applications for fireplace installations.
Available in small granules/grains it is a excellent material for insulation, It is used to stop the escape of heat and to prevent condensation in flue-liners.
Used for insulating your chimney, flue and firebacks, clay-fire-bricks and cast-iron-firebacks.
Vermiculite is a hydrous, silicate mineral that will not burn and is classified as a phyllosilicate and that expands greatly when heated. Exfoliation occurs when the mineral is heated sufficiently, and the product is routinely used in domestic fires and fireplace installations.
The insulating properties of vermiculite significantly reduces the heat loss in cold weather and keeps the interior cool in hot weather. Used for insulating solid fuel and wood burning stove liners, it reduces the amount of condensates by keeping the flue warm, it also holds the liner rigid to aid sweeping
Vermiculite is used to back-fill in many cases during fireplace installation, used to insulate flue liners, Used to back-fill firebacks with mortar in weak mixes