A marble back panel is the section within which the insert electric or gas fire is installed (see image below). As standard a back panel has a 16.25 inch wide times 22.25 inch cut out. This back panel cut out will accommodate virtually all fires (99% compliant). Home fires require an 18 inch wide opening which can be done free of charge (this is very rare).

Three-piece marble back panel

on occasion it is advisable to cut a back panel into three sections, so as to make it more resilient to high temperatures. It is often used when: 1. Back panels are used with solid fuel fires (burning wood or coal), 2. or alternatively when high-efficiency inset Gas Fires will be used with the heat efficiency in excess of 5 kW. A standard one-piece solid marble back panel be suitable for all standard gas or Electric Fires.

What materials are suitable for a fireplace back panel?

For obvious reasons fireplace back panel have to be made from non-combustible material such as marble. Cheap MDF fire surrounds with remember the back panel or only suitable for Electric Fires are not suitable for Gas Fires.