Do gas fires & solid fuel fires crack a marble or granite hearth and Fireplace Back Panel?Marble is a common material that is frequently used in fire surrounds. Marble is an ideal material to use for back panel is as it is non-combustible. Materials such as MDF would I not suitable for use with gas fireplaces. Certain high-efficiency gas fires have outputs in excess of 4.5 to 5 kW and can crack a marble back panel.
Ways to prevent a marble back panel from cracking
1. We would strongly recommend that you have your marble back panel cut into sections. Usually the back panel is cut into three or more sections to allow for expansion and contraction and hence prevent the back panel from cracking.
2. It is possible to use a granite back panel rather than a marble back panel which is more heat resistant and thermostable.
Do high-efficiency gas fires crack a marble or granite hearth?
As the heat is generally directed towards the back panel rather than the fireplace hearth, it is not common for a high-efficiency or high output fire to crack or damage a fire hearth in any way. If you would like to be extra cautious, then specify a hearth that is cut into three sections to allow for expansion and contraction. Solid fuel fires Both marble and granite will crack when exposed to high temperatures, such as those of a solid fuel fire.
In order to prevent both the hearth and back panel from cracking it is advisable to have them slabbed. Slabbing is a process which involves cutting the back panel and hearth into sections and filling the back with cement. This makes the marble and granite more resistance to heat and will prevent it from cracking. The usual cost for slabbing is £100 per piece (hence £200 to slabbed a granite hearth and panel)