clear

In carpentry, a clear is the unobstructed distance between two surfaces, walls, structural members, or obstacles. It is the actual working space available, as opposed to the nominal or theoretical dimensions shown on a drawing. A doorway's clear might be 32 inches wide even though the rough opening is 36 inches, because the frame consumes material on both sides. Framers, finish carpenters, and installers must understand clears because they determine what can physically fit and function.

Clears become critical when fitting cabinetry, appliances, or mechanical equipment into built spaces. A refrigerator with a 35-inch width needs a cabinet clear of at least 35.5 inches to 36 inches to be installable without forcing. Similarly, a staircase with a 7-foot-6-inch headroom clear allows safe passage for most people but marginalizes anyone over six feet tall. Building codes often specify minimum clears: a hallway must have a 36-inch clear width for accessibility; a bathroom requires a 21-inch clear depth in front of a toilet.

Measuring and accounting for clears

Carpenters measure clears from the finished surface inward. Drywall thickness (typically 5/8 inch), paint, trim, and hardware all consume the nominal dimension. A 10-foot wall measured stud-to-stud becomes something less when finished. Clears are reduced further by baseboards (usually 5/16 to 7/8 inch proud), crown molding, or door jambs. A kitchen peninsula might be nominally 48 inches but have only a 45-inch clear on one side if trim and a baseboard are installed on both faces.

Clears also describe distances in three dimensions: the clear width of a doorway, the clear depth of a closet, and the clear height of a room or underside of a beam. A contractor bidding a basement finishing job must verify the clear height at the lowest point, especially near mechanical systems or ductwork, to determine whether 7-foot-8-inch ceilings are feasible. Sloped ceilings, dropped soffits, and structural beams all reduce usable clear height.

Common mistakes occur when carpenters work from nominal framing dimensions rather than measured clears. A 2x10 joist is not 10 inches deep; it is 9.25 inches. A 2x4 stud is 3.5 inches wide. Over the course of a kitchen remodel or built-in installation, treating nominal sizes as clears can result in cabinets that do not fit, appliances that bind, or doors that cannot swing. Always measure the actual clear space on site, account for finish materials and hardware, and verify fit before ordering materials.