SigmaDek’s aluminum-deck package includes posts, beams, joists, ledgers, railings, stairs, and porcelain deck boards, which, the company says, won’t decay or warp and are noncombustible and impervious to insects. SigmaDek says its prefabricated decks require less labor and time to build than conventional wood ones; video at the company’s website shows a two-level deck being assembled in three hours. Decking comes in five finishes (special-order colors available). Lighting, gates, and glass rail panels can be added. For now, SigmaDek distributes the system only in California. Prices average $60 to $90 per square foot. SigmaDek, sigmadekus.com