METHOD STATEMENT OF
PLUMBING & SANITARY
INSTALLATIONS
1 ADMINISTRATION
1.1 Construction Schedule
A construction schedule shall be prepared based on the target dates given by
the client/consultant.
All efforts shall be made to adhere to this schedule. It will be reviewed weekly
and revised if any delays occur due to unforeseen and unavoidable
circumstances, keeping in mind the final date of completion.
1.2 Materials
A ‘Material Proposals’ schedule shall be submitted to the Client / Consultant
giving details of materials, manufacturer’s name, technical details etc. Once
these are approved, procurement will begin and a “Material procurement
schedule” will be submitted.
Total care shall be taken to ensure that the materials that finally arrive at
site meet all requirements of specifications and the bill of quantities, for
which the store-keeper and site engineer should be responsible
1.3 Workmen
Adequate workforce shall be deployed at all times to meet the approved
construction schedule. The workforce shall be suitably augmented as
demanded by actual site conditions.
1.4 Safety Plan
A safety plan shall also be submitted prior to commencement of work. Due
care shall be taken as regards all the safety aspects of the works. Relevant
PPE (Personal Protective Equipment) shall be used by all personnel working
on the installation.
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2 INSTALLATION
Given below are method statements for general plumbing installations.
2.1 External piping - Sewerage
2.1.1 Mark pipe lines in ground according to working drawings.
2.1.2 Excavate trenches to required depths with proper barricading.
2.1.3 Prepare base for laying pipe
2.1.4 Lay pipes according to specified gradient.
2.1.5 Backfill trenches in layers including compaction.
2.2 Shaft Piping
2.2.1 Mark for pipes on the plastered shaft walls according to details in the
working drawings. Ensure that the plastering is completed as it will be
almost impossible to plaster walls after the pipes are in place.
2.2.2 Fix brackets as per details shown on the working drawings. A clear gap of 25
to 50mm shall be maintained between pipe and wall surface.
2.2.3 Clamp pipe assemblies on to the brackets. Make sure the pipes are in ‘line’
(horizontal runs) or in ‘plumb’ (vertical stacks). Where expansion /
contraction will be a concern, ensure that pipes are not rigidly held to
brackets.
2.2.4 Make cut-outs on the shaft walls for branch pipes at locations shown on the
drawings.
2.2.5 Insert sleeves wherever required. Ensure that annular space in sleeves is not
more than 25mm. annular space shall be filled with yarn and flexible sealant
after installation of pipe through the sleeve.
2.2.6 Provide branches on the pipe assembly for connections to internal pipework.
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2.2.7 Provide isolating valves on water supply pipes at locations shown on
working drawings; at easily reachable heights.
2.2.8 Test the pipes for leaks under specified pressure for the specified duration.
2.2.9 Tests must be witnessed and approved by client’s representative.
2.2.10 Paint the pipes as per approved color code and provide identification labels
where called for.
2.2.11 Take measurement of pipes installed. A representative of client must be
present and should acknowledge the records.
2.2.12 Terminate soil, waste and vent pipes with vent cowls at specified heights
above terrace level. Ensure that vent cowls are not terminated within one
meter (horizontally and vertically) from any window openings.
2.2.13 Terminate water supply risers with automotive air vents (with isolating
valves) and down pipes with drain plug/drain valve – all as per drawings.
Ensure that water supply pipework would be self-venting and self-draining.
2.2.14 Connect the soil stack(s) to inspection chamber(s) at ground level.
2.2.15 Connect waste stacks(s) to the gully trap(s) at ground level. Connect the
gully trap(s) to the inspection chamber(s).
2.3 Pipes in wall chases
2.3.1 Make sure that walls are at least rough-plastered and finish levels are
marked by the civil contractor. If proper cladding levels are not marked, the
pipes could be too deep or too shallow inside. Pipes deep in the wall will
require use of extension nipples at faucets. Wall flanges of concealed stop
cocks, concealed shower mixer etc. will not fit-in correctly.
2.3.2 Mark pipe lines on walls as shown on the working drawing.
2.3.3 Chase the walls to required depth using a chasing machine.
2.3.4 Assemble piping starting from branch left in shaft and install in the wall
chase with clamps. Use pre-fabricated assemblies wherever possible.
2.3.5 Locate fixture outlets according to working drawing and tile-module
drawings. Title modules shall be marked on walls by the civil
contractor.
2.3.6 Plug all openings and test the pipework for leaks under specified pressure
and for required duration. Test should be witnessed and approved by
authorized personnel.
2.3.7 Apply anti-corrosive coating or wrapping on the pipe, as specified (if metal
pipes are used). Ensure that the tested pipe joints are not disturbed.
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2.3.8 Insulate hot water pipes with the specified material.
2.3.9 Note: Wherever possible, pipes may be pre-insulated/pre-wrapped, leaving
joints, prior to installation in the wall chase.
2.3.10 Close the wall chases with cement mortar. If site conditions require a depth of
more than 100mm to be chased, it is advisable to use a suitable mesh while
plastering and ‘making good’.
2.4 Pipes in sunken floor or suspended in
ceiling (Drainage)
2.4.1 Make sure that base water-proofing of toilet floors is completed.
2.4.2 Locate and mark positions of soil and waste outlets. Make core drills where
necessary.
2.4.3 Assemble pipe headers and connect them to branches left in the shaft for
this purpose. Pre-fabricate wherever possible.
2.4.4 Make sure that pipes are in proper slope and are supported adequately.
2.4.5 Always ensure that the spacing of supports is as per specifications. Ensure that
floor traps are installed in level (not tilted) so that the water seal is not
diminished.
2.4.6 Test the pipes and attend to leaks, if any.
2.4.7 Supervise the filling of sunken floors by civil contractor so that the alignment
and slope of drainage pipes are not disturbed. It is in the plumbing contractor’s
interest to ensure that water proofing of the core drills is done and tested.
2.4.8 Keep all open ends plugged to prevent ingress of construction debris.
2.5 Sanitary fixtures & CP fittings
2.5.1 Flush the installed pipework (water supply and drainage) to remove debris
or blockages, if any.
2.5.2 Install sanitary fixtures, faucets and washroom accessories.
2.5.3 Check CP fittings for leaks and firmness. Refit them if necessary. Ensure that
proper tools are used. They must not make scratches or any other kind of
damages on the chrome plated fixtures.
2.5.4 Commission the toilets in the presence of the client’s engineer.
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2.5.5 Handover the toilets formally using the forms provided for the purpose.
2.6 Disinfection
1.1 The water distribution system should be thoroughly disinfected before
being put to use. The following simple procedures will ensure satisfactory
results:
- Flush and clean water tank(s) and distribution pipework with potable
water to remove dirt and any foreign matter.
- Fill the tank(s) with water mixed with chlorine solution at the rate of 50
parts per million. Retain chlorinated water in the system allowing the
chlorine to spread throughout pipework.
- Open the farthest draw-off points or drain plug/valve to draw water.
Repeat the procedure till chlorine is felt at all locations when checked at
random.
- Drain out chlorinated water and fill the system with potable water.
3 DOCUMENTATION
3.1 As-Installed Drawings
3.1.1 Mark changes made from the working drawings; if any. These records should
be maintained from time to time during progress of work.
3.1.2 Prepare ‘As-Installed’ drawings. This is an essential requirement often ignored.
After the construction team leaves the project site, it would be impossible
to identify pipe routings etc. without these drawings.
3.1.3 Hand them over to the client with specified number of hard and soft copies.
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3.2 Operation & Maintenance Manuals
3.2.1 The O & M manuals should contain following minimum information:
3.2.2 A brief description about the project and the installations carried out.
3.2.3 Schedule of mechanical / electrical equipment installed.
3.2.4 Schedule of sanitary fixtures installed.
3.2.5 Schedule of as-fitted drawings.
3.2.6 Manufacturer’s operation & maintenance manuals and any warrantees issued
by manufacturers.
3.2.7 List of recommended spare parts.
3.2.8 Notes / recommendations on preventive and remedial maintenance works.
3.2.9 List of manufacturers with their local contact details.
3.2.10 Technical catalogues of important products used on the installations.
3.2.11 Reports / certificates of all tests conducted during progress of work and any
commissioningreports
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