A fire pit can add a warm and cozy atmosphere to a patio. Fire pits can be elaborate constructions or simple rings of metal or masonry, as big around and as deep as a homeowner wants. Fire pits should always be built where there is plenty of open space and ventilation and no flammable material, including plants and trees, nearby. Open pits well removed from a house require no vents, but those installed on attached patios or as part of an outdoor room should have a vent to direct smoke and rising heat safely away and catch any sparks.
Locate a fire pit in an open area, away from house walls or low-hanging tree limbs. Set it in a hole dug in the ground if possible, with a thick sand base, or place it on solid concrete blocks set into a masonry patio. Line the pit with a metal ring for the most safety. Build a small fire and watch the direction the smoke takes naturally.
Build a sturdy trellis or pergola around the fire pit, large enough that heat will not ignite wooden elements. Make this structure wide enough to provide comfortable seating for guests around the fire pit and high enough to not interfere with activities around the pit, such as cooking hot dogs or marshmallows. Set the framework behind any built-in benches or seating.
Buy an outdoor hood, preferably of copper or stainless steel, although some powder-coated aluminum or steel hoods will work. Position the hood over the fire pit -- high enough that even a tall person will not come in contact with it. Set it directly over the fire pit but tip it or angle it slightly if desired to direct smoke and excess heat away from a house or tree. Suspend it with hooks fastened into the framework of the trellis or pergola.
Build a vent or hood into a masonry-surrounded outdoor kitchen or room. Put the fire pit into a barbecue-style brick or stone pit, with brick or stone walls around it. Secure a vent to the wall or walls with concrete screws or anchors or similar fasteners. Incorporate this type of vent into the overall plan for the outdoor space. Place the fire pit on the side farthest from the house.