GIMME SHELTER- Let's get grillin': How to build a backyard firepit
Q: We just moved to town and want to take advantage of the last few days of summer. Any suggestions for building an easy and inexpensive backyard firepit?
A: One main purpose of landscaping is to entice people to enjoy the outdoors, and firepits are a simple, cheap way to transform your backyard into an inviting and usable space. In fact, I once used the following plan to help an after-school group of fourth grade girls build a firepit in only a few hours and for less than a hundred bucks.
First, pick a spot for the pit about 100 feet from any house– conveniently close, but safely distant. The spot should be relatively flat, with no overhanging branches, heavy leaf matter, or other combustible materials nearby.
Remove any grass within a four- or five-foot radius of your future pit. Although green grass is not combustible, a grassy firepit area will be difficult to maintain, since you'll have to remove the dry clippings whenever you cut the grass. Hoe the spot level if it's not already.
It's important that the spot be well-drained, so your pit doesn't puddle whenever it rains or when you water the fire to put it out. Before you start, pour a lot of water on your chosen spot and make sure it does not continue to hold water after a few hours.
Once you have a clear site, lay down 2-4 inches of drainage gravel in a circular area of two or three feet in diameter. If desired, also lay down weed control fabric in about a four foot radius around the gravel, but not directly over it where the fire will burn.
Next, spread an inch-thick layer of stonedust over top of the gravel and weed control fabric, all of which can be bought at any basic hardware store. You should end up with about a 10 foot diameter firepit in all. When I built the firepit with kids, I just dumped a big pile of stone dust directly on top of the gravel, and let them stomp it flat around the pit. If you want your design to be a little more geometric, just spray paint a circular blueprint for the pit and surrounding stonedust before you start.
Finally, stack up a stone wall around the pit to contain the fire. There are a variety of possible materials to use for the wall, and the best one really depends on your personal taste. Segmental retaining blocks are the simplest to lay, but they don't look very natural; paving stones look a little better and are also easy to stack. Or, you can get natural, flat stone from a local quarry or landscaping firm. Stay away from sandstone or other sedimentary type of rock, which can crack violently when heated. Instead, use a metamorphic type rock like granite.
Simply dry-stack the stone around the perimeter of the firepit until you've built a low, stable wall. You'll need only a six- to twelve-inch high wall for a three- or four-log fire, but stack the wall higher if you plan to build bigger fires. A fire lacking oxygen will be very smoky, so make sure there are some gaps between stones in the wall, and that the wall is low enough to allow a breeze to ventilate the fire.
There are a few other considerations to take into account when planning your firepit: Make sure the top of your wall is relatively level if you plan to cook on the pit, so that you can lay a metal grate across the top of it. Before you start building, check to see what local fire codes, if any, apply to outdoor fireplaces, and make sure you follow the rules. Keep a fire extinguisher or hose nearby, and don't build fires when the weather has been particularly dry, or when it's very windy. Finally, always put the fire out properly, by dousing it with plenty of water and spreading the combusted materials.