What Is A Standard Stair Tread Size
Here is a drawing detailing our standard stair tread and riser dimensions.
What is a standard stair tread size. The stair tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at right angle to the tread s leading edge. But we recommend that stairs should be at least 48 inches wide so they don t feel cramped. 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. Most stair treads measure between 8 and 10 inches long with longer treads being used on larger staircases.
For recommendations on rise run combos see the tip below. Because they only sit on the top of the stair the length of the tread is limited to the size of the average step. Harvard university lists typical tread sizes between 8 and 11 1 2 inches. Stair tread depths shall be 11 inches 279 mm minimum.
Most stair treads are not made to wrap around the lip of the stair. Nine inch stair treads are the most common lengths. Standard stair tread dimensions. Unit run is carefully considered based on both safety and cost.
Standard code requires that each stair tread fall between 9 inches and 11 inches 22 9 cm and 27 9 cm to allow people to safely ascend and descend stairs. A prime example is the standard stair width. Staircase code states that stairs must be 3 feet wide or wider. At the same time staircase code measurements do allow for some flexibility since most measurements are accompanied by minimums or maximums.
The stair treads should be at least 36 inches wide. The minimum tread size is commonly stated as 9 inches for residential construction. A tread thickness b bull nose height 1 1 16 c bull nose depth 1 d internal length 36 42 or 48 e return length 13 f tread width 11 g return extension 1 h return width 1 i external length 38 5 44 5 or 50 5. 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.
The maximum allowable stair rise is 7 3 4 inches and the minimum stair rise is 4 inches.