Means Of Access † provision is required for maintenance and
inspection of drainage systems. This should occur at:
the head (highest part) or close to it
a change in horizontal direction
a change in vertical direction (gradient)
a change in pipe diameter
a junction, unless the junction can be rodded through from an
access point
long straight runs (see table)
Maximum spacing of drain access points (m)
- Small access fitting is 150 mm dia. or 150 mm ¾ 100 mm.
Large access fitting is 225 mm ¾ 100 mm.
Rodding Eyes and Shallow Access Chambers † these may be used
at the higher parts of drainage systems where the volume of
excavation and cost of an inspection chamber or manhole would be
unnecessary. SACs have the advantage of providing access in both
directions. Covers to all drain openings should be secured to deter
unauthorised access.
Ref. Building Regulations, Approved Document H1: Foul Water
Drainage.
To: Small
access
fittingLarge
access
fittingJunction Inspection
chamberManholeFrom:
Drain head 12 12 22 45
Rodding
eye^2222224545
Small
access
fitting12 22 22
Large
access
fitting22 45 45
Inspection
chamber22 45 22 45 45
Manhole 45 90Simple Drainage---Access Location