When building a hearth, one of the most important considerations is hearth size, as this will affect the room in which the hearth is built. A hearth must often be built to a certain code established in your town or state. When considering hearth size, take into account the size of the stove or fireplace you are installing, as well as the size of the room the stove or fireplace is in. A smaller room may necessitate a smaller hearth, but remember that a larger stove needs a larger hearth not only for support, but also to prevent flammable materials from being too close to the stove.
A hearth acts as support for a stove or fireplace, but it also prevents fires. It must be made of non-combustible materials such as stone, brick, or concrete, and the hearth size must be large enough that any stray embers or flames that can escape the stove or fireplace land on the hearth rather than on a carpet, piece of furniture, or other flammable material. Local building codes will often spell out how large a hearth needs to be to meet code, and it is always smart to go a little larger than the required amount. Going smaller, however, is unwise and may not meet the minimum hearth size your local codes spell out.
If you have purchased a wood stove, the reading material included with the stove may spell out how large the hearth needs to be. Because a wood stove is often made of iron, the stove itself can be extremely heavy. Your hearth size will need to be large enough to support the weight of the stove, which means the hearth may need to be wider, deeper, and stronger than a fireplace hearth. Many hearths are made of concrete, which is a good choice for a strong support. A stone or brick structure can be built on top of the concrete hearth for aesthetics.
If the stove or fireplace is in a large room, the hearth size should be larger as well. In a smaller room, a small hearth is appropriate. It is important, however, to make your hearth large enough to prevent furniture from being placed too close to the stove or fireplace. The hearth must also still meet local building codes, regardless of the size of the room. A hearth that is too large, however, will take up too much space in the room and make the room feel cramped and uncomfortable. Conversely, in a large room, a hearth that is too small may make the room feel cavernous and uncomfortable.