Do high efficiency gas fires crack a Marble or granite hearth?
High-efficiency gas fires pioneered the way forward in terms of efficiency and saving money by using energy at better ratio than conventional gas fires. The average gas fireplace is 60% efficient, whereas high-efficiency gas fires are up to 98% efficient. Effectively this means on a conventional gas fire you lose £40 worth of heat loss for every hundred pounds spend. High-efficiency gas fires will only lose £2 for every hundred pounds spent on heating (assuming 98% efficiency).
Are high-efficiency gas fires good value for money?
1. Based on the argument above most home-owners would be swayed towards purchasing a high-efficiency gas fire as there are long-term cost savings to be had. However, high-efficiency gas fires cost in excess of £500 on average, whereas conventional gas fires cost as little as hundred and £150. Essentially, high-efficiency gas fires are not good value for money for the average home-owner which uses a gas fire occasionally as a decorative focal point.
2. Some would argue that there are greater savings to the environment that should be considered and for those reasons high-efficiency gas fires are much better value than conventional gas fires.
3. It is also important to note that all high-efficiency gas fires are glass fronted and do not have a open living flame effects. A large number of homeowners would find this major drawback, as essentially this makes high-efficiency gas fires look very similar to glass fronted electric fires.
Can high-efficiency gas fires crack a marble or granite back panel?
High-efficiency gas fires are much higher output than conventional gas fires and for that reason can occasionally crack in marble back panel. If you are purchasing a high-efficiency gas fire within output in excess of 4.5 kW, it is advisable to have the back panel cut into three sections to make purpose-built expansion joints. Granite is much stronger material that marble and should not need to be cut into sections. There is very minimal heat on fireplace hearth and for that reason the hearth does not need to be cut and rejoined into sections. 
