Stairs and Stairways
There are three dimensions of concern to the home inspector when inspecting stairs, they are:
Rise - the vertical distance between two treads
Run - the horizontal distance between one riser and the next, measurered along the tread
Tread Width - the depth of tread from front to back including the nosing
Straight Treads have some widely used dimensions, some may vary depending on your local building codes.
- Thickness - minimum of one inch if risers support the front of treads
- Rise - maximum 8 to 8 1/4 inches - depending on code of jurisdiction
- Uniformity - three eigths of inch maximum variation in rise
- Nosing or back slope - maximum 1 1/2 inches
- Tread Width - minimum 9 to 9 1/4 inches
- Run - minimum 8 1/4 to 9 inches
Stringer Dimensions
- Depth - minimum 2 inches by 10 inches
- Depth left after notching for treads - minimum 3 1/2 inches
- Thickness if supported by wall - minimum 1 inch
- Distance between stringers (risers do not support treads) maximum 35 inches
- Distance between stringers (risers do support treads) maximum is 47 inches
Headroom Clearance
Minimum required headroom clearance is usually from 6 foot 6 inches to 6 foot 8 inches