Railing Design Rules

Railing Height

• Local building codes differ slightly, but, in general, the standard height for the top of a railing is 34 to 38 inches. The Americans with Disabilities Act (ADA) suggests 36 inches as the best height for handrails; if you’re constructing a railing for public use, choose this height. A well-situated handrail height prevents accidental falls, while offering comfortable support for those needing the rail to balance or to walk safely.

Baluster Spacing

• Balusters spaced too far apart are a recipe for disaster. Your local building inspector might carry a 4-inch ball to test the space between balusters. If the ball passes between the balusters at any point, you might have to remodel the railing, repositioning the balusters closer together. Maximum spacing is usually 3-3/4 inches to prevent small children from slipping between the balusters and falling.

Post Placement

• Minimum spacing between posts ensures rail stability. Rail posts are the large vertical supports to which the top and bottom rails attach. The posts extend below the floor decking and attach securely to the deck joists beneath. ADA guidelines, which many local codes adopt, require a minimum spacing between posts of 8 feet, although 6-foot spacing is even better.

Special Railing Considerations

• If you reach for a handrail installed beside a wall and scrape your knuckles, the railing is too close to the wall. Install wall-mounted railings at least 1-1/2 inches from the wall. Generally, you can build a handrail of any width on a private deck; however, the ADA suggests that handrail widths that are between 1-1/4 and 1-1/2 inches are the easiest to grasp, making them the safest size to install.

Child Safety

• Even with safety railings, small children can lose their footing going up or down a staircase and fall. To reduce the risk of injury, install childproof gates at the head or foot of a stairway and accompany the child until he or she can safely hold onto the railing.