The first and most important step in fire pit construction is to check with local building codes to find out if there are any specific steps the builder must follow during construction. Backyard fire pits will need to be built in such a way that flammable materials, including furniture, homes, and trees overhead are far enough away from the pit that an out of control fire is less likely. Planning the location before fire pit construction will save the builder time and frustration, and considering nearby objects that may pose a fire hazard will ensure the fire pit is safe for regular use.
Fire pit construction will start with digging a hole in which a fire retardant base can be built. This base is often made of stone, concrete, or brick. The bottom of the hole dug for fire pit construction will need to be leveled off properly so the material built on top of the bare earth will also be level. Drainage will be a consideration as well; if concrete is being poured for the base, the builder should leave a hole in the center of the concrete slab for drainage. Other drainage methods are available and the builder should research the best options before beginning fire pit construction.
Choosing the material that will be used for fire pit construction is another important consideration that will impact the look of the finished product, the durability of the pit and surrounding areas, and the safety and effectiveness of the structure. Concrete, brick, and stone are the most common materials for fire pit construction. Flammable materials, especially synthetic materials, should be avoided, since they will easily catch fire and allow the flames within the pit to spread. Synthetic materials can melt and release toxic gases into the air. Choose between concrete, stone, and brick for the main material, and be sure to check into the cost of each type of material. Brick is generally the most expensive and difficult to install, while concrete is often the cheapest and easiest to work with.
Choose materials too that will provide insulation for the fire. This will keep the fire hotter longer. Many builders choose to build brick, concrete, or stone around a steel or iron fire pit insert that will help conduct heat and provide insulation. The fire pit should be built several inches or feet above ground level to help contain the materials to be burned. Building the walls too tall, however, could prevent oxygen from reaching the flames, meaning the fire will burn out quickly.