Manufactured outdoor fireplaces are constructed of stainless steel. Wood burning (with optional gas logs) and vent free gas are the primary technologies. Like their indoor counterparts, these fireplaces are installed inside a structured cavity, then covered with cultured stone or other exterior product to complete the over all look. The wood burning technology does require a minimum vertical flue system ranging from 15 to 24 feet. The vent free technology has limitations on outdoor porches with less than two permanently open sides.