New York State Building Code Deck Railing Requirements

Residential Deck Railing Basics

• New York State, like many states, incorporates elements from several sets of building code standards. The source of deck railing requirements across the U.S. is the International Residential Code (IRC), a set of standards related to all residential construction. These requirements apply to both ground-level decks and those built above the first story of a home. Deck railing must be able to support a person weighing 200 pounds leaning on it while also fitting into the overall structural support of the deck.

Deck Railing Measurements

• The Prescriptive Residential Deck Construction Guide, the main guideline for deck building in the U.S., includes elements from the 2009 IRC. This guide requires decks that are 30 inches or higher above grade to have a guardrail system. The top deck railing, or rail cap, must have a maximum span of 6 feet between support posts. The rail cap must not exceed 36 inches of distance between itself and the joist below; 2-by-6 lumber is recommended for the rail cap in the Prescriptive Guide, although different dimensions may be allowed, such as 2-by-4 or 2-by-8.

Specific New York State Requirements

• The city of New York provides information on its website related to deck railing requirements. This information is a guideline that draws on the New York State building code for decks and porches. The top rail of a deck must be at least 42 inches above grade. The space between all railings must not exceed 5 inches, which is the approximate size of child’s head. This prevents a child, or anyone else, from falling through the deck railing.

Important Deck Railing Tips

• Many failures of decks have been the result of insufficient attachment to supporting members, such as posts and ledgers. Although nails are often used to attach deck railings, wood screws are seen as a much more reliable fastener for support and stability. Support posts to which deck railing is attached should be supported by footings rather than by the flooring of the deck. Elevated decks in particular must provide a stable system of posts, joists and ledgers to fully support the weight and stress applied to deck railing.