Spiral stairways shall meet the following requirements.
Spiral staircase regulations.
It is important to note that where there is a contradiction between bs 5395 part ii and part b and m of the building regulations part b and m take precedence.
The clear walking path on a particular staircase.
All building regulation spirals must comply with the 100mm sphere rule i e there must be no gaps greater than 99mm anywhere on the spiral staircase.
The usable surface of the stair tread must be a minimum of 26 inches in width measuring from the center of the staircase to the outer handrail.
Spiral staircase code overview.
These specifications show standard stair dimensions for height tread degree rotation degree and many more details for each.
K1 building regulations states that there is no minimum width requirement for a spiral staircase but it should be built in accordance with bs 5395.
1067mm diameter can have 1 extra victoria or plain baluster.
The document governing spiral staircase building regulations in the uk is british standard 5395 part 2.
1917 121 b 1 stairways shall conform to the minimum dimensions of figure f 1.
Spiral stairs must meet the vertical clearance requirements in paragraph d 3 of this section.
Vertical clearance above any stair tread to any overhead obstruction is at least 6 feet 8 inches 203 cm as measured from the leading edge of the tread.
This document is summarised in the table below with categories given for each spiral application and the relevant maximum riser heights and minimum widths.
Spiral staircase regulations for commercial and public use category c small semi public d semi public or e public stairs tend to be for staircase projects in commercial and public spaces.
Our spiral stair building code and ibc stair code specifications provide technical details about the different code and non code packages we offer for commercial and residential projects.
So if the client is ordering a scandinavian parisienne or a victoria 1067 or 1194mm it must have riser bars.
In situations where space is limited the diameter is at the discretion of the building inspector.