Geberit Syphonics Design Guide
Transcript of Geberit Syphonics Design Guide
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Syphonic Roof Drainage
Design Guide
Advanced Roof Drainage Technology
SYPHONICS
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Design, Manufacture and Installation
Millenium Plaza, Cardiff.
TSB Call Centre, Cardiff.
Honda Car Factory, Swindon.
The Light Office Block, Leeds.
The Lowery Galleria, Manchester.
Tesco, Old Swan.
Stoke City FC.
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Geberit Pluvia is the leading syphonic
roof drainage system used throughout
the world.
Architects, Consultants and
Contractors have chosen the system
for some of the most prestigious and
ground breaking building designs due
to the freedom and flexibility it
provides.
Pluvia uses the ingenious gravity
induced vacuum principle to create a
syphonic action, which allows the
complete drainage of a roof area with
smaller diameter pipes than used in a
conventional gravity system.
Geberit Syphonic roof systems are
widely used in the industrial and
commercial sector for all roofs.
Geberit Pluvia Advantages
new architectural flexibility in building and use
no slope in pipework required less underground pipes less sitework fewer pipes and fittings reduced pipe dimensions less space required self cleaning action a simple and speedy fastening
system
The Geberit Pluvia System is fully approved by the BBA. This includes outlets, pipes &
fittings, and the dedicated design software.
All installations carry a minimum of a ten year product and design guarantee, and are carried out
by a Geberit Syphonics approved installer.
The product range includes outlets to suit most roof designs and finishes, with a comprehensive
range of contact foils to suit the majority of roof membrane materials currently on the market.
RIBA approved CPD seminars are available. Please contact Geberit for more information.
Conventional System
Fall 1 - 3 %
Many down pipes Fewer down pipes
Long underground pipes Short underground pipes
No fall necessary
Syphonic System
Design, Manufacture and Installation
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2Software
Geberit Pluvia DLS software
The highly advanced software package easily allows
the calculation of the most complex roof projects. It
offers distinct advantages:
convenient to operate considerable time savings very easy to use provides
- Isometric drawings
- Hydraulic calculations
- Material list incl. fixing components
- Cost calculation with ready to mail tender
documents
The Geberit Pluvia Outlets are developed for all
types of roof structures. Due to the different discharge
rates of the outlets (6 l/s,
12 l/s or 25 l/s) an
economical layout of the
roof drainage system can
be reached. The wide
range of contact sheets
and accessories allows
connection to most roof
finishes.
The Geberit HDPE range of pipes and fittings
accompanies the Pluvia outlets for total drainage.
Geberit HDPE is available 40mm - 315mm, and can
be jointed in a variety of different methods including
electrofusion, butt
welding and
mechanical coupling.
The outstanding
material
characteristics of
Geberit HDPE allow
specifiers and
contractors to design
and pre-fabricate pipe runs away from the site of the
installation. Pipe runs can be created in a safe, clean
environment ensuring secure and accurate fabrication
as well as considerable material and labour savings.
The Geberit rail fixing system
The Geberit Pluvia fastening system was developed for
the installation of exposed, horizontal roof drainage
piping.
The expansion and contraction of the piping, which
occur after installation are absorbed by the system
itself. For this purpose, all mechanical forces are
transmitted to the square steel rail routed parallel to
the pipe.
Geberit rail fixing features
Large spans between beams can be bridged. Fewer brackets on roof structures Pre-assembly on the floor is possible:
- alignment of clamps on the rail, or
- alignment of clamps and of HDPE pipes on the rail
The clamps are conveniently secured with wedges. Only very simple tools are required for the assembly
of the system.
The clearance required to install insulation against condensation is accounted for in the design.
The system overcomes fixing constraints on steel profile roofs.
The forces associated with changes in length as a result of temperature fluctuations are absorbed by
the rail fastening.
Drawings and calculations
available from the Geberit
Technical Department or
Geberit Syphonic approved
installers.
Geberit Pluvia should only be installed by a Geberit
Syphonics approved installer.
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3Methodology for Designing a Pluvia System
Step 1Determine the roof(s) drainage patterns.
Step 2Calculate the areas of roof(s) draining to each outlet(see capacities on page 7)
Step 3Determine the rainfall intensity rate
Method AGeberit recommend using 108 mm/hr (0.03 l/s per sq.m.)
In the UK this figure provides a frequent return rate for a 2 minute storm which ensures the systems self cleansing routine is activated.
Method BUse the method and data provided in BS EN 12056 part 3. We do however advise against using the very high rainfall intensity rates that can be generated if long life spans for the building and high safety factors (categories) are used in the calculations.
Example:Project located in London requiring 25 year life span protection, Category 3 Safety Factor. This will result in a rainfall intensity rate of 236 mm per hour. In reality this will mean that once every 112.5 years for 2 minutes there may be a storm with a rainfall intensity of 236 mm/hour. Using this high rainfall rate will result in the systems pipework being massively oversized, which will result in the system not operating syphonically frequently, requiring a high level maintenance programme to check for silt build up in the pipes.
Geberit recommend using the rainfall rate mentioned in Method A and allowing any potential higher rate rainfall totemporarily accumulate on the roof (for valley gutters this may require some over sizing of the gutter to provideadditional storage capacity).
Example: If the 236 mm/hrs protection is required, design a primary system to cope with 108 mm/hr. The build up fromthe excess over 2 minutes would be 236
-108128 30 = 4.3 mm
If the above mentioned temporary storage method is not acceptable then one of the three options below may be used:
Option 1Weir overflows in the parapet walls.
Option 2A secondary syphonic overflow system.
Option 3A separate internal overflow system (gravity). (See page 6 for detail)
In all roof designs an emergency/warning overflow must be provided to indicate a blockage within the system.
Step 4Contact the Geberit Technical Department or Geberit Syphonics approved installer to design and calculate a system.
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4Steel Profile Roof Deck(without Vapour Barrier Clamping unit)
Series 7 Outlet (12l/s capacity)
Electroweld Coupling and Brackets(Creating on Anchor Point)
Geberit Pluvia Rail System
Series 7 Outlet359.551.00.1
Roof Membrane
Thermal Insulation
Steel RoofProfile Decking
900 Bend
Vapour Barrier
Series 7 Outlet359.550.00.1
Roof Membrane
Thermal Insulation
Vapour Barrier
Steel Gutter using a Clamping Ring
Geberit Clamping Ring359.568.00.1
Gutter
Series 7 Outlet359.551.00.1
Steel Profile Roof Deck(with Vapour Barrier Clamping unit)
Electroweld Coupling and Brackets(Creating on Anchor Point)
Geberit Pluvia Rail System
Steel RoofProfile Decking
900 Bend
Vapour BarrierClamped Seal Unit
Min 380 mm
Steel Gutter using a Contact Sheet/Foil
Flange to beriveted, solderedor weldeddepending ongutter finish
Gutter
Series 7 Outlet359.636.00.1
Min. 350 mm
Typical Roof Types
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Series 7 Outlet (12l/s capacity)
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Concrete Roof (no Vapour Barrier)
Detail Showing Two Roof Finishes
Concrete Roof (with a Vapour Barrier)
Gravel
Electroweld Coupling and Brackets(Creating on Anchor Point)
Paving
Geberit Pluvia Rail System
Roof Membrane
Insulation
Series 7 Outlet359.551.00.1
Geberit Contact Sheetto be Bonded to RoofMembrane
Roof Membrane
Insulation
Series 7 Outlet359.550.00.1
Geberit Contact Sheetto be Bonded to RoofMembrane
Concrete Slab
900 Bend
Promenade Outlet (with a Vapour Barrier) Timber Roof Construction
Electroweld Coupling and Brackets(Creating on Anchor Point)
Geberit Pluvia Rail System
Roof Membrane
Insulation
Insulation
Series 7 Outlet359.550.00.1(Remove top grating
Geberit Contact Sheetto be Bonded to RoofMembrane
Promenade top359.635.00.1
Concrete Slab
900 Bend
Series 7 Outlet359.551.00.1
50mm Ventilation Gap
Timber Joists
12mm Plasterboard
Geberit Contact Sheetto be Bonded to RoofMembrane
Timber RoofDeck
RoofMembrane
Electroweld Coupling and Brackets(Creating on Anchor Point)
Geberit Pluvia Rail System
Concrete Slab
900 Bend
Vapour Barrier
Vapour BarrierPaved Area
Vapour BarrierClamped Seal Unit
Vapour BarrierClamped Seal Unit
Typical Roof Types
Detail Showing Two Roof Finishes
Gravel Paving
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Remove and discardfunction disc fromoutlet
Adaptor* Ref: 6147/DVW
*Flow capacity of outlet withadaptor similar to standard outletbut with water depth 90mm(normal 40mm)
50mm high standpipe
Roof deck
Pushfit joint
Series 7 outletcover holds unitin place
Series 7 Overflow Adaptor
PVC Roof Finish
Geberit PVC Coated OutletFlange to be bonded toPVC Roof MembranePluvia Grating
Concrete Slab
Pluvia Outlet359.501.00.1*
*359.500.00.1Stainless Steel Finish
56
214
15mm max
Asphalt Roof Finish
PluviaGravel/ClampingRing 359.511.00.1 (Fixing extension Rodsand nuts extra240.816.00.1)
Pluvia Grating
ConcreteSlab
15mm Max
Mastic Asphalt
Pluvia Outlet359.500.00.1
56
214
Insulation
Stones or paving Slabs
90
280
Pluvia GratingHeld in place bya wing nut
Pluvia Outlet359.502.00.1
Concrete Slab
25 Litre Outlet
Geberit PVC CoatedOutlet Flange to bebonded to PVC RoofMembrane (This outlet isalso available without PVCcoating 359.573.00.1 forother roof finishes
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Series 7+ Outlet (25l/s capacity)
Series 5 Outlets (6l/s capacity)
Typical Roof Types and Overflow
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7Technical Specification of Outlets
Series 5 Outlet (Small)
Min. flow capacity 1l/s +
Max. flow capacity 6l/s
Discharge capacity (outlet in gutter) 1-5l/s
Outlet spigot diameter 56mm
Standard Series 7 Outlet
Min. flow capacity 1l/s +
Max. flow capacity 12l/s
Discharge capacity (outlet in gutter) 1-10l/s
Outlet spigot diameter 56mm
High Capacity Series 7+ Outlet
Min. flow capacity 8l/s
Max. flow capacity 25l/s
Discharge capacity (outlet in gutter) 20l/s
Outlet spigot diameter 90mm
Design Parameters
Min. pipe diameter 40mm
Max. pipe diameter 315mm
Min. flow velocity 0.7m/s
Min. water to air ratio 60%
Max. negative pressure 40-160mm (PN4)* -800mbar
Max. negative pressure 200-315mm (PN3.2)* -450mbar
Max. negative pressure 200-315mm (PN4)* -800mbar
Min. 2 outlets to be installed on a system
Emergency warning overflows must be provided on all roofs
Pluvia outlets should be spaced no further than 20 metres apart
Pluvia outlets should be spaced no further than 10 metres from end of gutter
All horizontal pipes must be laid level (no gradient)
+ This equates to 33m2 based on 0.03l/s (108m/hr)
*PN4 denotes a thicker wall pipe
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8Geberit recommend that a maintenance programme is
always implemented on completion of the project.
The intervals between inspection will depend on the
location of the building. The maintenance programme
should include:-
Clearing of all outlets of any debris
or silt as shown in figure 1.
a Remove lid
b + c Remove function disc
d Rinse function disc with
water
e Wipe outlet with cloth
1 2 3
Check that no pipes connecting
to outlets are blocked with silt etc,
if blockages are found they can
be removed by using a water jet
through the outlet after removing
the top unit and function plate (a,
b & c in figure 1)
Ensure all outlets have gratings
and tops in place. Order spares
from Geberit if necessary.
Maintenance
a
b
b
Figure 1
c
d
e
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Geberit Ltd.New Hythe Business ParkNew Hythe LaneAylesford, Kent ME207PJ
Other Geberit Syphonic literature available: Product and price guide
Other innovative products available within the Geberit Ltd. product portfolio include: Geberit Terrain UPVC & HDPE soil, waste and underground drainage systems Geberit Mepla water supply Geberit Terrain Rainwater Systems Geberit Duofix wall hung sanitaryware installation systems, WC and urinal
flushing systems, electronic washroom solutions and shower toilets
Please call 0700 4323748 or visit www.geberit.co.uk for more information.
Tel:+44 (0)1622 717811Fax:+44 (0)1622 716920www.geberit.co.uk
Registered office as postal addressRegistration Number 761885 SYPHONICS
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