TL;DR
Stair nosing is the front edge of a tread that projects beyond the riser below, giving the foot extra depth on the way up and a visual cue on the way down. The IRC allows a projection of 3/4 to 1-1/4 inches where treads are shallower than 11 inches, with a curvature radius limit and no more than 3/8-inch variation between steps.
What it means
Stair nosing is the front edge of a tread that projects beyond the riser below, giving the foot extra depth on the way up and a visual cue on the way down. The IRC allows a projection of 3/4 to 1-1/4 inches where treads are shallower than 11 inches, with a curvature radius limit and no more than 3/8-inch variation between steps. On finished stairs the same word names the protective trim piece, often aluminum or matching hardwood, installed over that edge where flooring materials change.
Where it sits in the glossary
Stair nosing is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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