Backyard fire pits are growing in popularity, and it's important to think safety when burning a fire outdoors, just as you would when starting a fire in the living room fireplace. Safety: Fire pits come home is an online newspaper article that makes some recommendations. For best results, follow the manufacturer's directions when using your fire pit and obey other common sense rules. Here is some of the other advice the article offers:
...(K)eep the fuel pile small and contained within any outdoor fire unit, and keep the device away from combustibles.
Fire authorities around the nation vary widely in their recommendations for keeping the devices a safe distance from buildings or other combustible material. In Bismarck, fire authorities recommend a minimum distance of three feet; in Omaha, one official recently told the Omaha World-Herald that 25 feet is more appropriate distance.
Fire units are unsuitable for use on decks of multi-family type residences, such as an apartment building or duplexes...
Fire experts recommend using untreated hardwood in these manufactured pits, though some units are fired with natural gas or liquid propane.