Building a Deck on My Home, Specific Laws and Regulations That Need to Be Followed

Wood-DeckLocal building codes are in place to make sure that the wood deck you install is safe and secure. Decks are also one of the top projects to add value to your home, so they are worth the effort. Here is an overview of codes in the U.S. If you have questions about your local codes, you can ask the building department when you apply for a permit to build your deck.

In this Complete Home Remodeling Guide we will discuss specific regulations that need to be followed when building a deck on your home.

Basic Structural Requirements

These requirements are based on the International Residential Code, or IRC. This code states that decks off the main floor of the house must have strength of at least 40 pounds per square foot. A 10×10 deck, or 100 square foot deck, should be able to hold 4,000 pound, equal to 20-25 adults. If the deck is elevated, it must be able to handle 60 pounds per square foot. Local codes determine how high off the ground a deck is to be considered elevated. In some municipalities it can be as little as 4 feet.

Joists must be built from 2” material such as multiple 2”x4” boards or a 2”x12” joist. Materials 4”x4” or 6”x6” can be used for posts but not for joists.

In addition, all decks must use treated lumber to keep them from rotting. Rot will weaken wood and cause it to lose strength quite rapidly. Pillars should be at least 4×4 for non-elevated decks and 4×6 or 6×6 for elevated decks. Decking beams should be bolted to the posts using carriage bolts of at least ½” diameter.


Deck Railings

If your deck is more than 2-3 feet off the ground – it varies locally – then you’ll be required to have railings on it. The railings should be at least 3 feet high. Stairs leading to the deck should also have railings. Handrails must be at least 2 5/8” in diameter. Railings and hand rails vary quite a bit based on local code, so check with your code office or building inspector.

Landing Zones

The area at the foot of the deck stairs must offer a firm landing zone of at least 3’x3’. The zone should be level and stable.

Common Code Violations on Decks

There are several common ways in which codes are violated. In most cases, they can be remedied without too much hassle. The first is building a deck out of standard-grade lumber. When this is done, some building inspectors will make you take it down and start over. Some municipalities will allow you to stain and seal the deck or paint it with approved weather-grade products.

Secondly, the use of too few fasteners or those that are too small or not corrosion-resistant is a common violation. Your local codes department will supply you with a list of approved building materials for your deck, including what type and how many fasteners you should use. Finally, some decks are built with too few joists. To meet IRC code, they should be 12” apart and no more.

A deck is a great outdoor remodeling project, but you want to make sure you follow all the rules so you don’t have to tear it down and start over. These specific codes for building decks should give you a good place to start. Check your local codes for more details.

For guides on deck remodeling, kitchen remodeling, basement remodeling, and bathroom remodeling projects, visit our helpful learning articles for tips and tricks!

Share Your Experience

Join the discussion and share your knowledge on this home improvement topic.