Stair Tread Overhang

This applies to nosings on treads and landings.
Stair tread overhang. This video will provide you with what the international building code refers to as the maximum distance a stair tread can overhang. This is a measurement from the nose of the tread to nose of the tread. If the risers are solid the nosing must project between 0 75 and 1 25 inches and must be uniform between two stories with variations of less than 0 375 inches.
The tread nose defines the outer edge of each tread walking surface. This means that there is a small surface that can be used to remove the tread from the entire stair assembly. The tread nose defines the outer edge of each tread walking surface.
Nosings the overhanging portion must be curved with a radius under 0 56 inches. Building inspectors are now asking for no nosings on staircases for offices flats or other public stairs. Beveling on noses must be less than 0 5 inches.
If the stair tread was installed with screws and glue chances are you would not be trying to replace this tread. Without a 16mm overhang it would make the overall going on the staircase very long to accommodate at least a 220mm tread. I ve heard different reasons for why the nosing exists but i ve not been able to find a definitive source.
The run is the measurement of the tread which needs to be a minimum of 10 inches if the tread has and overhang on it see image. The reference number is 1009 7 5 1 on page 254 of the 2012. You are not required to have an nosing overhang on your stair treads.
Stair tread nose yellow arrow in the photo of stone steps above is the projection of the stair tread out over the stair riser.