Standard Stair Tread And Riser Size

A stairway in which there is a noticeable variation between the risers is a safety hazard.

Standard stair tread and riser size.

The greatest riser height within a flight of stairs cannot exceed the smallest by more than 3 8 inch. Details are at stair tread dimensions. These dimensions may be useful when laying out a staircase or if you have general questions about the size and shape of a traditional tread or a retro tread. 8 1 4 to 9 stair tread thickness.

Stair riser heights and stair tread depths should be within the parameters of the code to avoid any potential trip hazards for inconsistencies. Additionally the riser measurement of all of the treads should be as close as possible to identical. Stair tread run or horizontal depth. Definition of detailed specifications for open riser stairs.

However the americans with disabilities act ada lists the minimum tread size as 11 inches which would be the effective minimum and likely the average size of the tread for any stairs built for public use. 1 or greater tread is supported by the riser. Regulated by building codes stair details specify the sizes of risers and treads stair widths the placement of handrails and guardrails and construction methods for fabricating stairs. A uniform flight of stairs provides a safety factor.

Here is a drawing detailing our standard stair tread and riser dimensions. Required 1 to 1 1 2 projection beyond the riser face. Inconsistencies or variations in risers or treads could interfere with the rhythm of the individual using the stairs. Stair details refer to the standard requirements for each of the various components of a flight of stairs.