Residential Deck Railings

May is National Deck Safety Month, and a perfect time to give your deck a once-over before the outdoor summer gathering season begins! Your residential deck is a place for gathering, accessing your home or yard, and enjoying the great outdoors. Deck railings are one of the first lines of defense in the safety of the people on your deck.  While they're under minimal loading in a typical condition, the code plans for a worst case scenario with the loading and construction requirements of your railings.  Fortunately, these requirements are easily demystified with some of my favorite deck resources.

Code Requirements

The IBC requires deck railings to be a minimum of 36" high, above the top surface of the deck, for decks that are more than 30" above the top of the grade below.  Railings installed on decks less than 30" above grade must also follow all of the code requirements - meaning if you have a railing, even if it's not required, it must meet the code criteria.

Railings are required to have infill members, called balusters, or other panelized infill material.  This infill, as well as the entire railing, cannot have any opening large enough for a 4" sphere to pass through.  The exception to this is the triangular opening between a railing and the location where the stair tread meets the stair riser. 

Residential deck railings are required to resist a 200 pound point load applied at the worst case location, typically a horizontal load at the top of the railing.  Also, the infill members/panels must resist a 50 pound concentrated point load.

The Structural

All of the requirements above have an impact on the loading that the railing connection at the deck framing.  Essentially a point load at the top puts a rotation force at the bottom that has to be resolved.  This works with a piece of hardware called a tension tie, in conjunction with structural screws and blocking. 

When you look at the code requirements for railing connections today, compared to what they were even 10 years ago, it seems completely ridiculous.  Those railings look and feel like they're not going anywhere - but that's the point.  It's too critical of a safety feature to skip.

Assessing Your Railing

When we bought our house, the deck was a the biggest item of contention for me.  Especially the railing.  Here were a couple of my red flags, and how we resolved them.

Railing Attachment

My biggest red flag was that the guard rail posts were attached to the outside of the deck rim board (the board nailed to the ends of the framing members on the outside edge), with just two nails.  There was no blocking, no bolting, and certainly no hardware.  I could even pull the posts right off of the rim without much force at all.  We added hardware and bolts to the connection and made certain the other components of the railing were still secure

Hog Wire Infill Panels

We didn't like the closed off feeling of the wood balusters, so we switched out the infill for the popular hog wire look.  This galvanized livestock wire has a grid of 4" spaces, and creates a more flow-through look to your railing.  It's important to consider the fastening of this to your main deck posts as it still must resist that 50 pound force. 

Conclusions

Your railing construction is important to keep yourself, your family, and your guests safe on your deck.  Code railing requirements are a simple way to ensure the safety and a long life of your deck structure.  In most cases, basic deck structures do not require a professional stamp to obtain a permit, as long as they follow the guidelines and meet code requirements.  Check out my round up of my favorite deck resources here. 

Do you have more questions about residential deck railings? Comment below!

Disclaimer: Although I am an engineer by profession, I am not YOUR engineer.  All content and information in this post (and on this website) is for informational and educational purposes only, does not constitute professional advice and does not establish any kind of professional-client relationship by your use of this website.  Refer to my full disclaimer for more information.