Building Construction Handbook, Eighth Edition

Open Riser Timber Stairs ~ these are timber stairs constructed to

the same basic principles as standard timber stairs excluding the

use of a riser. They have no real advantage over traditional stairs

except for the generally accepted aesthetic appeal of elegance.

Like the traditional timber stairs they must comply with the

minimum requirements set out in Part K of the Building Regulations.

Typical Requirements for Stairs in a Small Residential Building ~

upper floor landing

wall string hooked over

landing trimmer

minimum going

220 mm

pitch

line

outer string

floor level

rise ... 220 mm max.

treads housed

into strings

minimum

overlap

16 mm

maximum pitch 42ƒ

Recommended clear width for

all stairs is 800mm minimum,

but 900 mm wall to wall or

wall to centre of handrail

is preferable. Clear width is defined in BS 585-1

as "unobstructed width between handrail and

face of newel", but see also page 686. A

reduced clear width of 600mm is acceptable

for access to limited use space such as a loft.

Aggregate of going plus

twice the rise to be 550 mm

minimum and 700mm maximum

no opening which will allow

a 100 mm diameter sphere

to pass through ... see

details on following page

no opening which will

allow a 100 mm diameter

sphere to pass through

handrail

balusters

newel

post

minimum headroom 2.000

900

mm min.

1000

mm max.

Timber Open Riser Stairs