How much weight should a deck of a given area support, either according to building codes or convention?

In my local (Massachusetts) building code, I found the answer for floors (40 lbs/ft2 live load), but I'm not sure if that is the same for decks. So I'm curious what the codes of various areas say about the load capacity of deck, and what people think is reasonable to design for regardless of code.

If your answer references building codes, please state the locality.

  • Is this a real question? What's the given area? Jul 22, 2010 at 23:16
  • I think the idea was more of a general weight/area guideline rather than tying it down to a specific deck size.
    – Doresoom
    Jul 22, 2010 at 23:39
  • @Mike, it's an L shape, so think of it as two rectangles next to each other. One is 13 x 20 ft, the other 11 x 12 ft. Jul 23, 2010 at 14:31
  • There are a lot of different loading conditions that you have to prepare for (eg, drifting snow, people, dead load, etc), and in the case of snow, you often have different requirements even within a given state. Contact your local permits office, they should be able to tell you. Also "reasonable" will vary with the question "do you plan to add a hot tub?"
    – Joe
    Jul 23, 2010 at 19:57

1 Answer 1


I found the following VERY detailed tutorial on determining joist span based on expected live and dead load: American Wood Council

The weight your deck will need to support will depend whether you get snow and how much, whether there will be a roof over the deck, whether the deck will be sheltered by any other means, what do you expect to do with the deck (outdoor kitchen, hot tub, outdoor parties), etc.

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