Regulations and codes are a pain in the neck for builders. But they are necessary, and some of them are really important to make your house a safer place to live. Deck railing codes are really important, and remember them when building your deck (if you are not using a contractor)
All decks higher than 30″ above grade must have a guardrail. But if your deck is lower than 30″ and you would like to install a railing system you must still meet code requirements. The International Residential Code (IRC) for single family houses requires guardrails to be at lest 36″ in height measured from the deck surface to the top of the rail. You are allowed to build taller guardrails as long as they conform to all other requirements stated in the code (click here to check all code recommendation for deck construction).
Instead of putting a girder at the end of the joists, you’ll need a beam under the joists, so they can extend past that support. This framing style is called post and beam, and the overhang is a cantilever. If you would like to have a a cantilever deck the code have the rules in Section R507.5. Deck joists can cantilever up to 1/4 of the joist span. But you’ll notice when you look at the portion of the span table for joists with cantilevers that the joist span for decks with a cantilever is often less than the span for the same sized joist without cantilevers. The next subsection requires that solid blocking is required over the beam when there is a cantilever.
Even if your local code jurisdiction hasn’t adopted the 2015 IRC, most building officials will look favorably on an ICC sanctioned code provision. So run the table by your building official for approval before using it. And stick with a builder or contractor that understand the rules and local codes, of course.