Minimum Stair Tread Size
The minimum tread size is commonly stated as 9 inches for residential construction.
Minimum stair tread size. As general rules of thumb for achieving comfortable relationships between riser and tread dimensions the following formulas can be used. This distance must be at least 10 inches. Minimum 10 inch stair tread depth with nosing or minimum 11 inches with no nosing. This narrow side must have a minimum tread depth of 10 inches.
Stair tread depths shall be 11 inches 279 mm minimum. 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. However if the steps do not have nosings and the steps have solid risers not open risers the minimum tread depth is 11 inches. 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.
Staircase risers should be adequately deep to allow a majority of your foot to have enough room to rest on the stair. When it comes to other materials the thickness may differ. Harvard university lists typical tread sizes between 8 and 11 1 2 inches. The minimum general tread depth remains 11 inches but it is measured at a right angle from the leading tread edge that is 12 inches from the narrowest side.
According to building codes stair tread for wood stairs has to be anywhere from 1 to 1 in thickness. The greatest depth at the 12 inch mark must not exceed the smallest on any other tread by more than 0 375 inches. This is because stair treads can be crafted from thick oak to think stainless steel. The riser height shall be measured vertically between the leading edges of adjacent treads.
Handrail height to be placed a minimum 34 inches to 38 inches. 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. Handrail graspability to be either type i or ii with a minimum 1 1 2 inch clearance from a wall. Stair tread depths shall be 11 inches 279 mm minimum.