What is meant by 'minimum distance to combustible materials'?
When you install any stove it is important that you adhere to the manufacturer's declaration regarding minimum safe distances to combustible materials as this will be fundamental to you and your family's safety. Any stove which has actually been CE tested in an EU notified laboratory will clearly state these distances within their instructions. The problem is that there are still a lot of stoves on the market which purport to be CE tested and which are clearly not (rest assured these are not sold by The Stove Yard) and therefore any declared minimum distances stated by these unscrupulous manufacturers or importers are likely to be pure guesswork and must be assumed to be potentially unsafe.
The CE test is the only way to accurately determine these minimum safe distances and that's why there's such a wide variation from model to model. There is no rule of thumb either which can be adopted to replace this critical laboratory test – and remember, these distances are 'minimums'. To calculate these safe distances the EN13240 standard for freestanding stoves takes accurate worst case scenario heat readings from the sides and the rear, and for inset stoves, the EN13229 standard, the heat readings are taken from the sides and the top (referred to as the 'shelf'). There is no shelf (or top) distance test for free-standing stoves, hence a number of stove manufacturers recommending the use of non-combustible mantels (see our FAQ on this subject).
An example of a clearance to combustible materials diagram from the Hi-Flame Alpha 1 manufacturers handbook.
Radiant stoves, because they get extremely hot, will require much greater combustible distances than convector stoves with the same heat output which use air movement in bodywork channels to disperse their heat. Generally, the greater the heat output from the stove then the greater the safe distances that are required – but not always. So if your combustible distances are very tight then you may need to choose your stove based mainly on how easily it will comply to your combustible distance requirements, possibly a convector stove, or alternatively to use some form of heat shielding to protect your combustible areas.
A combustible material is anything that is flammable. Sometimes this is not always obvious – the biggest offender being plasterboard with its cardboard outer which invariably uses a wooden frame for support (stud partitioned walls). It never ceases to amaze us at The Stove Yard how many stove installations we come across where the plasterboard's flammability or stud work have not been taken into consideration when applying safe combustible distance requirements. Wooden fire surrounds and skirting boards are others.
Such combustible materials issues can therefore make it unsafe to install a free-standing stove (not forgetting the flue) in timber garden sheds, shepherds huts and any manner of off-grid structures where virtually everything is combustible if the appropriate safety measures are not applied. Despite this some people carry on regardless. Fortunately reputable manufacturers, like Chilli Penguin, which specialises in stoves for the off-grid market and are all too aware of such issues, supply optional purpose-made and safety tested heat shields for their stoves, so really there's no excuse to put yourself at risk when you're going off grid. Charnwood also offer a great decorative heat shield solution with their range of Vlaze vitreous enamel panelling. At the moment there is no standard for installing stoves in these type of temporary structures however Soliftec have produced a guide for installing stoves in boats and many of its safety considerations could equally be applied to shepherds huts and sheds etc.