Deck Handrails and Guardrails

Handrails and guardrails are two distinct railing types that serve different primary functions on decks, though they are closely related.

A handrail is a railing that is grasped by the hand and provides support and assistance for people transitioning across changes in elevation, like stairs or ramps. The main purpose of a handrail is to help guide people safely up and down stairs/ramps and prevent falls caused by loss of balance. Handrails run continuously alongside stairs/ramps.

A guardrail, on the other hand, is a protective barrier that prevents people from falling off elevated walking surfaces. Guardrails are taller than handrails and designed to physically block people from falling over the open edge. Building codes require guardrails on decks, balconies, landings, etc. that are 30 inches or more above grade.  This requirement of 30 in or more is important because many decks are low enough that they do not require a guard rails continuously along the edges of the deck.  In most Washington DC Road homes though the deck will come off of the ground level which puts the deck in entire story above the rear of the building lower level or basement. This may be a half a level or a full level depending on the height of the ground in relation to the basement but in most cases decks are high enough in Washington DC and Capitol Hill row homes that they require guard rails around the perimeter of the deck.

structure of deck handrails

While handrails provide graspable support, guardrails rely more on their overall height and presence as a barrier to mitigate fall risks. Guardrails do not necessarily need to be graspable like handrails.

In some cases, a single railing system can serve as both a handrail and a guardrail by meeting the respective height, graspability, and strength requirements of each. However, codes generally treat them as distinct components with their own provisions.

The different intents result in differing code specifications. Handrails have stricter guidelines around sizes/shapes for gripping, height ranges for stairs/ramps, and use requirements. Guardrails focus more on minimum heights, spacing between balusters, and overall strength.

deck handrails

Proper handrail height is important for safety and accessibility on deck stairs and ramps. Building codes provide specific height ranges that handrails must fall within. According to the International Residential Code (IRC), handrails must be installed between 34 and 38 inches measured vertically from the sloped plane adjoining the tread nosing or finish surface of ramp slopes.

This height range ensures handrails are high enough that average-height adults can use them comfortably, while still being low enough for children or those of shorter stature to reach safely. In addition to the overall height, code also governs how the measurement is taken when stairs or ramps have open risers. For open risers, the handrail height of 34-38 inches must be measured from the leading edge of the tread. This accounts for the open space where a missed step could occur.

Local codes sometimes modify the acceptable height range slightly. For example, some jurisdictions specify a maximum height of 37 inches rather than 38 inches for added safety. Installers need to check applicable local handrail height requirements in addition to the model IRC stipulations.

Proper spacing between vertical balusters is specifically important for both guardrails and handrails, fir particular areas of safety. For guardrails, which serve as barriers to prevent falling from elevated surfaces, the spacing requirements are quite strict. Most residential codes dictate that the opening between any two vertical guardrail balusters cannot exceed 4 inches. This eliminates larger gaps that could potentially allow a child to slip through and fall. Additionally, the triangular openings formed by the bottom rail, and walking surface must be small enough to prevent passage of a 4 inch diameter sphere on decks and 6 inches on stairs, in most cases. These rules aim to prevent both falls and entrapment hazards.

Handrail spacing requirements are slightly more relaxed, as handrails are graspable assistants rather than complete barriers. Typically, handrail balusters cannot be spaced more than 4 inches apart. The baluster must be more than 1.5 inches away from the wall to allow a hand enough room to grasp, in most cases.  

In both cases, strictly following the spacing maximums is important rom a safety perspective. Guardrail spacing prevents falls, while proper handrail spacing enhances accessibility and prevents falls caused by loss of balance on stairs and ramps. Some local jurisdictions may adjust the spacing dimensions slightly, so verifying the code requirements of the specific area is necessary when planning and constructing deck railings.

Often, builders will use a 3.5 in with board as a spacing guide in installation of balusters.  The 3.5 in with board is common in a typical 2×4 piece of lumber and a scrap piece of lumber that can be used as a guide while this spacing is technically less than the minimum requirement it is often considered a good spacing guide because it verifies all baluster spacing is less than the minimum requirement.

deck handrails and guardrails

Use a contractor who understands and cares about doing things right.  Always, feel free to reach out to us here at Dupont Decks and Patios.  You can call us at (202) 774-9128.  You can find us online at and you can email us there as well at

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structure of deck handrails

Deck Handrails and Guardrails

Handrails and guardrails are two distinct railing types that serve different primary functions on decks, though they are closely related. A handrail is a railing