Manual of Purpose-Made Woodworking Joinery

Stair regulations guide 97

● form part of means of escape (reference should be

made to Approved Document B: Fire Safety;

● provide access for disabled people (reference should

be made to Approved Document M: Access and facili-

ties for disabled people).

Dividing flights

Figure 6.16: A stair in a public building which is

wider than 1.8m should be divided into flights with

relief handrails which are not more than 1.8m, as

illustrated.

Length of flights

Figures 6.17 and 6.18: The number of risers in a flight

should be limited to 16 if a stair serves an area used as

a shop or for assembly purposes. Stairs having more

than 36 risers in consecutive flights should have at

conversions where there is not enough space to estab-
lish this height, the headroom will be satisfactory if the
height at the centre of the stair- width is 1.9m, reduc-
ing to 1.8m at the side of the stair, as illustrated at 6.14.

Clearance

Clearance, not now referred to in the amended AD
K1, was a traditional requirement of NLT 1.5m
between flights, measured at right angles to the pitch
line of a stair, to the underside of any flight or struc-
tural intrusion above.

Width of flights

Figure 6.15: Contrary to previous regulations (which
gave 800mm as the minimum unobstructed width
for the main stair in a private dwelling), no recom-
mendations for minimum stair widths are now given.
However, designers should bear in mind the require-
ments for stairs which:

Width (w)

1.8 m 1.9 m

W

2

Figure 6.14 Reduced Headroom, if required, for loft

conversions.

Width

of flight

Joinery width of stair

Figure 6.15 Width of flight.

NMT 1.8 m NMT 1.8 m

Figure 6.16 Division of flights over 1.8m wide.

Stair

width

Flight

NLT Stair widht

Landing

NLT 30º

Flight

Figure 6.17 Change of direction via a landing.

NLT

220 mm

NMT

220 mm

NMT 42º

Pitch

NMT 16

risers per

flight

Figure 6.18 Category 1 Stair, indicating the maximum

permissible pitch, rise and risers per flight – and the

minimum going.