Standard Deck Railing Height: Code Requirements and Guidelines

When building a deck railing, there are many factors to consider, but the most important one is deck railing height. Many people are not aware that there are strict guidelines for how high a deck railing can be, and failure to adhere to those guidelines can result in injury or fines.

The minimum deck railing height allowed is 36 inches in most states and provinces. California and a handful of other states mandate a 42” minimum deck railing height. Railing height is measured from the top of the deck surface to the top of the deck rail.

While these guidelines seem fairly straightforward, they can become confusing when dealing with deck stair railings, different railing types, and decks with multiple levels above grade.

In this article, we’ll tackle all of those confusing points about deck rail height and deck rail code so you can have a safe and aesthetically pleasing deck railing.

Standard Deck Railing Height

Do I Need a Railing on My Deck?

Building code for deck railing indicates that you need a deck railing for any deck that is 30” or more above grade. If your deck is below 30”, then you do not need a railing for most North American jurisdictions. A handful of states and some provinces, mandate railings begin at 24” above grade – not 30”.

Remember that if your deck is 20” or 25” above grade, you still might want to have a railing. Fluctuations in grade level, shifting earth due to freeze/thaw, aesthetics, or safety might compel you to install a railing anyway. And if you aren’t sure what your local code states, it’s best to stay on the safe side and install a railing if your deck is more than 2’ off the ground.

If you do opt to install a railing system on a deck that is below a 30” grade, it is not required to meet deck railing requirements as it becomes an accessory, not an essential safety feature of the deck as long as your local code dictates a 30” minimum.

Do Deck Stairs Need Railings?

Yes, if there are more than two steps. The definition of “step” often confuses people building deck stairs, so let’s clear that up.

The code states that deck stairs that have four or more risers need a handrail. There is always one more riser than stair tread, so you could say that any set of deck stairs with three or more stair treads needs a handrail. This would also be accurate.

So, if your deck stairs only have two treads or three risers, you do not need a handrail for your steps unless you live in the state of New York – more on that, below.

If you’ve determined your deck stairs do need a railing, then you must ensure it is at least 34” vertically from the nosing (the front edge of the tread) to the handrail.

Also, many jurisdictions mandate that you cannot be any further than 30” from a handrail while on a flight of deck stairs. This usually isn’t an issue for most deck stairs, as handrails are on both sides. If you have a long, unbroken set of deck stairs – over 60” – then you’ll need a handrail in the center of your steps to adhere to deck stair building code.

There are more code requirements for the handrail itself, in terms of making it graspable for all types of hands, but we’ll go over those in-depth, below.

Deck Railing Height Code Requirements

Deck railing height code requirements are straightforward, although there is some deviation between states and provinces regarding a standard railing height for decks. In terms of stair railing code requirements, code is nearly uniform across North America.

Merely giving the height requirement is somewhat misleading, however, unless you know where that measurement is taken. We’ll look at this further, below:

What Is the Difference Between a Stair Rail and a Handrail?

When building deck stair rails, there is some confusion with terminology. You’ll hear the terms “handrail”, “guardrail”, “stair rail”, or even “graspable rail” used interchangeably. In this case, a stair rail is simply a handrail – on stairs.

A handrail or graspable rail is the same thing. All stair railings need handrails – or graspable rails – that enable a person to grab onto. For example, a 2×4 laid flat as a top rail would not suffice as a handrail. Why? Because it is too wide to be considered “graspable”. Think about it – it is hard to comfortably grasp the width of a 2×4.

Therefore, the width of your circular handrail can only be between 1 ¼ and 2” wide. This allows people to quickly and effectively grasp a railing in the event of a slip or trip. A handrail with edges, such as the top of a 2×4, can also be used as long as the sides of that 2×4 have indentions that can be considered “graspable” – the indentions must be at least 1 ¾” from the top fo the rail on both sides.

Also, keep in mind that a stair rail must be at least 1 ½” away from the wall it is attached to, if applicable. This gives a hand enough space to grab and hold in the event of a fall or slip. Some jurisdictions mandate at least 2” of clearance – so check your local code to be sure.

Lastly, deck stair guardrail code mandates – in all jurisdictions – that guardrails begin and terminate at a post. That means that your deck handrails must attach to a post at the top and the bottom. This is to ensure the solidity of the handrail, assuming the post at the bottom – called a newell post – is properly fastened to a footing in the ground.

How Is Railing Height Measured?

Railing height on a deck is measured from the top surface of the deck surface to the top of the horizontal deck rail. It is not measured to the top of deck posts or any other part of the railing system except the top of the deck railing.

Deck Railing Height

Deck railing code

Deck railing height is a minimum of 36”. In some states such as California, the minimum height is 42”. There is no maximum height. A railing is only necessary if the deck is 30” or more off the ground, and 24” in certain jurisdictions.

Many states and provinces mandate deck railings to be at least 42” if the deck is 6’ or more off the ground. Deck railing openings can be wider apart – 4 ⅜ – between 36” and 42” to allow for better visibility. Below 36” openings are still only allowed to be a maximum of 4”, however.

Deck Stair Railing Height

Deck stair railing height code

Deck stair handrails height should be at least 34 vertical inches from stair tread nosing to the top of the stair handrail. It should be no more than 38 vertical inches from the stair tread nosing if the guardrail also acts as a handrail, which it does for most decks. If it does not, then you’ll need a separate handrail attached to your deck stair guardrail, between 34” and 38” in height.

If your deck stair guardrail is functioning as your handrail, then you have 4” of leeway to place your deck stair railing in a place that will provide the safest way for people to travel up and down your stairs.

Remember, you can have a maximum of three risers – or two treads – before you need a stair railing unless you are in New York.

The caveat to this would be if you had more than three risers that were very short – such as wide and shallow steps – which allows you to have many steps span a short elevation. In this case, you would only need a handrail if the top tread was 30”, or 24”, or more above grade.

Deck Railing Height Code Examples for Different States

What makes building code so confusing is that code requirements can change literally from town to town, much less state to state or between countries. As such, we’ll take a look at some sample states and what their code requires to enable you to draw some general conclusions.

California

California requires homeowners to have deck railings that are a minimum of 42” high. There is no maximum height. California is one of the few states that mandate 42” railings, and the requirements are no different than other states – 42” is measured from the top of the deck surface to the top of the deck railing.

On the other hand, California is in line with other states in that the required height for stair handrails is between 34” and 38”. There is a maximum height for stair handrails since stair rails must be easily accessed for all types of people to hold on to when moving up and down the stairs.

Florida

Florida deck railing height is a minimum of 36” from the top surface of the deck to the top of the deck railing. Stair railing height must fall within the range of 34” to 38”, is used as a handrail. Otherwise, a minimum of 34” is the only requirement for a deck stair guardrail.

Colorado

Colorado mandates a minimum of 36” from the top of the decking to the top of the deck guardrail. Also, a range of 34” to 38” is acceptable for stairway hand railings in Colorado.

An important variance to Colorado deck railing code requirements compared to other states is that handrails on stairs can be wood with indented grips, as long as they are between 1 ¼” and 2 ¾” wide at the top of the rail. Circular handrails, on the other hand, can only be between 1 ¼” and 2” in diameter.

New York

The state of New York requires all deck guardrails to be at least 36” high. Also, deck stair railings in New York must be between 34” and 38” high.

A difference found in New York compared to other states is that all deck stairs are required to have handrails if there are two or more risers. That means all stairs with at least one tread on a deck require handrails.

New Jersey

New Jersey allows for a minimum of 36” for deck guardrails. Deck stair handrails must be at least 34” and no more than 38” high.

Deck stair handrail size varies slightly in New Jersey, in that they mandate handrail diameter to be between 1 ¼” and 2 ⅝”. Handrails must be “graspable” which means you still cannot use a 2×4 or other shapeless block of wood.

Deck Guardrail Height Requirements for Canada

Canadian building requirements on deck guardrail and deck stair guardrail height are generally the same as found in the U.S., but with some slight differences.

Ontario

In Ontario, deck guardrails can be no less than 35” high if the deck is 5’11” above grade or less. If the deck is above that grade, then deck guardrails must be 42” or higher.

Deck stair guardrails must be between 35” and 38”, giving you slightly less wiggle room than most American building codes offer.

Interestingly, deck railing posts are not allowed to be more than 4’ apart if they stick up above the post. If they are part of a continuous top railing, then they can be 6’ or less apart.

British Columbia

On the opposite end of the country, British Columbia mandates a minimum of 36” for deck guardrails for all decks that are more than 24” above grade. All decks above a 6’ grade must have guardrails that are 42” high.

Deck stair guardrails in British Columbia must be between 34” and 38” high from the outside edge of the stair nosing.

Quebec

In Quebec, deck guardrails must be at least 36” high on all decks that are 2’ or more above grade. For decks more than 6’ above grade, deck railings must be at least 42” high.

Handrails must be at least 2” from any structure, which means that if you attach a handrail for your deck stairs to your house, then there must be at least 2” of clearance. Handrails are required when there are more than 3 risers on your deck stairs.

Quebec’s handrail height must fall between 34” and 38” high. Also, if your stairs are 43.5” or less in width, you only require one handrail for your deck stairs.

Conclusion

While generalizations can be made for many of the required measurements for code pertaining to deck railings and deck stair railings, it is critical to note that there are many variations between jurisdictions regarding code requirements. You must check the building code of your jurisdiction before erecting a deck railing or deck stair railing.

Remember that safety is priority number one, and failure to adhere to building code will ensure that your deck railing won’t pass code, resulting in fines or you having to completely re-do your railings.

Thanks again for taking the time to peruse this article. I hope you’ve found it helpful, and please drop me a line with any suggestions or comments about how I can make this article more informative. Best of luck with your next deck railing project!

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