Curved Stairs

Question 1

Circular stairs are constructed using?

Answer 1

Tapered stairs and curved stringers

Question 2

Specific Code requirements on circular stairs

Answer 2

-The min. Unit run at the inside stringer must be 150mm
-the average unit run at the center line of the stairs must be at least 300mm
-if closed risers are used they must be vertical

Question 3

For all stairs the layout lines on a blueprint always indicate

Answer 3

The nosing lines.

For circular stairs these (nosing) lines converge to a common point

Question 4

The main difference between a circular and spiral stair

Answer 4

Is that spiral stairs converge to a central support such as a column and are required to have a min. Tread width of 150mm rather then a max u run over 150mm

Question 5

I’m spiral staircases if each tread turns 30 degrees headroom must be achieved in?
Because?

Answer 5

11 units of rise

Because the back of the 12 tread is directly above the nosing on the 1st tread

Question 6

Spiral stairs are permitted to have a unit rise of up to?

Answer 6

240mm

Which is 40mm greater then regular stairs

Question 7

When tapered and rectangular treads are combined in a flight of stairs all the treads must?

Answer 7

Have a uniform run when measured at a point 300mm from CL of I/S handrail

Question 8

Why are spiral stairs not permitted means of egress?

Answer 8

Because of the steepness and the min. Unit run 150mm at the inside