Wall safes offer an enhanced level of security protection in certain circumstances. They can be easily concealed behind a wall hanging or picture. The door of the safe – the only part a thief will realistically be able to attack – is usually designed so as to minimize possible vulnerable points. For instance, many wall safes feature concealed hinges.
High quality wall safes are designed to be installed in concrete and brickwork. This arguably makes them more secure than a freestanding, bolted-down safe. These wall safes may also offer a certain degree of fire resistance for their contents. As with underfloor safes, this has more to do with how the safe is installed rather than being a design feature. Simply put, surrounding any safe with concrete is in effect a form of fireproofing. Many fireproof safes actually use a type of concrete as a fire resistant barrier.
It is entirely possible that a wall safe in concrete will protect its contents in the event of a fire, even if the safe lacks a fire rating. However, there are many reasons why it would be unwise to rely on an unrated wall safe for items that are particularly expensive, irreplaceable, heat sensitive, or of sentimental value.
For instance, the door of the safe will offer little to no fire resistance, as it (obviously) has not been encased in concrete. The construction of the door may even cause heat to be conducted, resulting in the interior becoming very hot very quickly. Also, as heat rises, the elevated position of the safe will likely contribute to it being subjected to very high temperatures. Furthermore, should the wall in which the safe is installed collapse (a common occurrence during intense fires), the safe will most likely burst, leaving its contents completely unprotected.
In America, where wall safes are more popular, it is possible to buy fire rated models which have been tested to independent fire resistance standards. These safes have had a fireproof material added to their door and bodywork. However, in the UK, such safes are rare, with freestanding safes being more popular.
To ensure your valuables are fully protected, you should always choose safes that have been independently tested, rated and certified. To do otherwise is to take an unnecessary risk which you could all too easily regret.