How Wide Are Balusters

In most instances, the gaps between the balusters (also called spindles) should not be greater than 4”. Four inches is equal to 101.6 millimeters; many building inspectors carry a 100 mm or 4-inch ball for measurement that should barely fit through the space between the guard infill components.

How wide should balusters be?

U.S. building codes mandate that balusters have no more than a 4-inch gap between them. This relatively tight amount of spacing still allows for visibility between spindles, but also stands as a safety measure to prevent small children from becoming stuck between spindles or from slipping through the balusters.

What is code for baluster spacing?

US building codes require that the space between balusters be no more than four inches—assuring that small children can’t slip through or get stuck between them. They must also be able to resist up to 50 pounds of pressure exerted over a 1-square foot area.