Vermiculite bricks are a service item, they withstand extraordinary temperatures and will protect your stove but much like the rubber wheels on your car are susceptible to damage and will eventually perish.
These vermiculite bricks line the fire chamber and protect the steel body from the heat produced by the fire.
Vermiculite bricks are a service item, they withstand extraordinary temperatures and will protect your stove but much like the rubber wheels on your car are susceptible to damage and will eventually perish.
They are fitted to the stove for insulation purposes, allowing your stove to burn efficently but also acting as a heat barrier and preventing the flame from reaching the steel stove walls.
A hairline crack in the brick will not damage your stove. Replace the brick if either the crack causes the brick to fall down or if you can see the steel body of the stove through the crack. It is advisable not to light your stove if the steel is visible. If your throat plate brick has fallen down don’t use your stove as it will distort the throat plate.
Once you notice crumbling you should replace the bricks.
We have a few tips on how you can make your bricks last longer:
Vermiculite bricks are cut from a pressed board. They is common misunderstanding that they are fired ceramic brick or a quarried stone. This is not true. Vermiculite is a naturally occurring mineral formed into board and then cut into shapes. Not only does it work hard during its lifetime but when you have finished with it you can put it on your garden and it will degrade in to the soil. It an aluminium-iron-magnesium silicate.
Cracks are caused by impact or vibration, often simply a log/solid fuel thrown in a little roughly or the door squeezed shut on an oversized log. Crumbling on the edges or corners is a sign that the vermiculite is beginning to degrade and is ready to be replaced. How long it lasts will depend on how much the stove is used, under average seasonal evening usage this will usually be years.
Pinking, if the bricks change to a noticeable pink shade this is sign that the stove has been over-fired, or burnt at excessive temperatures for a prolonged period of time.
When your fire bricks need replacing, we recommend buying fire bricks in sets for the following reaons:
Bricks are available on their own, should you wish to only purchase a single replacement brick.