As long as the 3 foot width standard is met you can expand the stairs width as far as you wish.
What is a standard stair tread size.
Here is a drawing detailing our standard stair tread and riser dimensions.
Nine inch stair treads are the most common lengths.
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.
A prime example is the standard stair width.
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.
Stair details refer to the standard requirements for each of the various components of a flight of stairs.
Most stair treads are not made to wrap around the lip of the stair.
At the same time staircase code measurements do allow for some flexibility since most measurements are accompanied by minimums or maximums.
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.
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.
For recommendations on rise run combos see the tip below.
Standard stair tread dimensions.
Most stair treads measure between 8 and 10 inches long with longer treads being used on larger staircases.
The stair treads should be at least 36 inches wide.
The minimum tread size is commonly stated as 9 inches for residential construction.
Increasing the length of the run by the smallest unit of measurement increases cost and the length of a staircase.
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.
Staircase code states that stairs must be 3 feet wide or wider.
But we recommend that stairs should be at least 48 inches wide so they don t feel cramped.
The maximum allowable stair rise is 7 3 4 inches and the minimum stair rise is 4 inches.