Now I would like to focus on fixed stairs. Each day we may walk up and down stairs at home and work and pay little attention to them. We take them for granted. What if the steps were not built or installed to standard? In most cases, it might cause us to trip or slip as we climbed on down.
The part you put your foot on when using stairs is called the tread. The end of the tread nearest the person is referred to as the nosing. The board between two treads is known as the riser. The height that a flight of stairs goes up is called the rise. The part that runs down the side of the stairs is referred to as the stringer. The height of the rise and width of the tread should be uniform throughout a flight of stairs.
Stairs also have railings. The part of the railing that runs up vertically is called the newel. The part of the railing that you usually place your hand on is known as the top rail. The rail in between the top rail and the stairs is termed the mid-rail. Per OSHA, if stairs have four steps then railing must be provided.
The main purpose of stairs is to move people up and down to different floors of a building. We also use stairs to move material up and down between floors using a dolly or other piece of material handling equipment.
You can find stairs with walls around them, which are called stairwells. You may also see stairs as standalone metal frames.
OSHA Code of Federal Regulation (CFR) 1910.24 is the standard for fixed industrial stairs. This section of the code has some useful information.
The stairway must carry five times the normal load but never less than a moving load of 1,000 pounds. It must also be a minimum of 22 inches wide.
The angle to the horizontal on any given stairway must be between 30 and 50 degrees, and any uniform combination of rising/tread dimensions may be used that will result in a stairway at an angle to the horizontal within the permissible range.
Table D to section (e) provides the specific length in inches of the rise and tread run based on the angle of the stairway to horizontal.
All treads shall be slip-resistant, and the nosings shall be of nonslip finish. In some cases, the builder uses welded bar grating for treads without nosings. These are acceptable if the leading edge can be readily identified.
If the stairway includes platforms, they should “be no less than the width of a stairway and a minimum of 30 inches in length” (1924, 2016).
Railings must be provided on the open sides of all exposed stairways and stair platforms. For closed stairways, a handrail must be provided on at least one side. People prefer the right. I always recommend installing handrails on both sides.
Vertical clearance above any stair tread to an overhead obstruction must be at least 7 “feet measured from the leading edge of the tread” to prevent someone from bumping their head (1924, 2016).
Several documents provide specific rules and guidance on stairs and ladders. The ones that safety professionals should be familiar with include:
- International Building Code, dated 2009
- 29 Code of Federal Regulation 1926.1052 OSHA Construction
- Proposed 29 CFR 1910.24 and .25, dated 1999, 2003, and 2010
- National Fire Protection Association Life Safety Code 101, dated 2012
- 29 Code of Federal Regulation 1910.23 and .24 OSHA General Industry
Americans with Disabilities Act 2010/Architectural Barriers Act, dated 1968 as amended
1910.24 Walking and Working Surfaces. https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9716 (accessed December 12, 2016.)