Frost Brochure Issue 03 - Catalog - Page 68
Roof Drainage - Design Considerations
ROOF CONSTRUCTION
Inverted Roof Assembly
Secured dome
Gravel guard
Roof finish
Membrane
Screed
Roof slab
Membrane
clamping collar
Insulation
Spigot adaptor
Body
Roof outlets are not multipurpose and products are
designed for use with speci昀椀c
types of roof construction
(e.g. cold roof, warm roof,
inverted roof parapet roof
and balconies). The depth of
structural slab, thickness and
location of insulation and the
type and location of waterproof
membrane are factors to
consider at the outset of any
drainage selection.
FLOW RATE
Parapet Roof Assembly
Membrane
Downspout
nozzle
Membrane
Grating
Connecting
spigot
Membrane
clamp
Body
Deck
68
Parapet wall
The quantity and types of roof
outlet to be used in a given
application must be related to
the roof area and anticipated
volume of rainwater to be
drained.
Flow rate is the maximum
amount of water (litres/second)
which a roof outlet will drain
and is in昀氀uenced by several
factors: grating free area (i.e.
gaps in the grating), sump
size, body free area, design
of the outlet, outlet size and
additional accessories such
as gravel guards and 昀椀lter
buckets.
