Plumbing and Sanitary Works SOP | Civil With Karthik

1. Purpose

To establish a comprehensive procedure for the installation of plumbing and sanitary systems that ensures compliance with local building codes, leak-free operation, proper drainage, and efficient water supply in construction projects.

2. Scope

This SOP applies to all plumbing and sanitary installation activities including water supply lines, drainage systems, fixture installation, testing, and commissioning in residential, commercial, and industrial construction projects.

3. Responsibilities

Project Engineer

Oversees the plumbing installation process and ensures compliance with design specifications

Plumbing Supervisor

Directs installation activities and coordinates with other trades

Safety Officer

Ensures adherence to safety protocols and proper use of PPE

Plumbers

Execute installation according to approved drawings and industry standards

Quality Control Engineer

Inspects installations and conducts pressure testing

4. Materials & Equipment

Piping Materials

CPVC, PVC, GI, PPR, HDPE pipes as per specifications

Sanitary Fixtures

WCs, urinals, washbasins, sinks, traps, shower units

Fittings & Valves

Elbows, tees, couplings, gate valves, ball valves, check valves

Installation Tools

Pipe cutters, wrenches, threading machines, pipe vises

Testing Equipment

Pressure gauges, hydrostatic test pumps, smoke testing devices

Sealing Materials

Thread sealant, solvent cement, PTFE tape, gaskets

5. Pre-Installation Requirements

Review and approve plumbing shop drawings

Verify that building structure is ready for plumbing installation

Check availability of all required materials and equipment

Coordinate with electrical and HVAC contractors to avoid clashes

Mark locations for pipe runs, fixtures, and fittings as per approved drawings

Obtain necessary permits and approvals from local authorities

6. Installation Procedure

1

Underground Drainage System Installation

Excavate trenches as per approved layout and required fall (1:50 to 1:100)
Prepare the trench bed with proper sand bedding (minimum 100mm)
Lay pipes with correct alignment and gradient
Install inspection chambers/manholes at specified intervals and junctions
Connect all lateral drains to main sewer line
Conduct water test before backfilling
Backfill trenches with approved material in 150mm layers with proper compaction

2

Water Supply Piping

Mark pipe routes on walls/floors as per approved drawings
Create chases/cutouts in walls for concealed piping (depth: pipe diameter + 25mm)
Install main water distribution lines first, then branch lines
Maintain minimum clearance of 25mm between hot and cold water pipes
Install isolation valves at each bathroom/distribution zone entry
Provide proper pipe supports at specified intervals (horizontal: 1.5m, vertical: 2.0m)
Pressure test system at 1.5 times working pressure for 2 hours

3

Drainage Piping System Inside Building

Install soil (100mm) and waste (75mm) stacks with proper support systems
Ensure all horizontal pipes maintain proper slope (1:50 for soil, 1:40 for waste)
Install vent pipes extending minimum 300mm above roof level
Provide cleanouts at strategic locations (base of stacks, changes in direction)
Install floor traps with minimum 50mm water seal
Connect fixture drains to waste pipes using proper P-traps
Conduct water test by filling the system and checking for leaks

4

Fixture Installation

Install water closets with proper alignment, secure fixing, and sealed connections
Mount wash basins at standard height (800-850mm) with secure brackets
Install shower trays/bathtubs with proper waterproofing and drainage slope
Fix kitchen sinks with appropriate sealant and secure mounting
Install faucets, flush valves, and other fittings as per manufacturer specifications
Connect fixture supply lines using flexible connectors with isolation valves
Apply silicone sealant at fixture intersections with walls/floors

5

Rainwater Drainage System

Install roof drains at specified locations as per drawings
Connect downpipes with proper brackets (maximum spacing 1.8m)
Ensure minimum 1:100 slope for horizontal rainwater pipes
Install rainwater harvesting components if specified in design
Connect rainwater pipes to stormwater drainage network
Provide expansion joints for long pipe runs (every 12m)

6

Hot Water System Installation

Install water heaters as per manufacturer guidelines and local codes
Connect supply and return lines with proper insulation (minimum 19mm thick)
Install pressure relief valves, non-return valves, and isolation valves
Ensure adequate support for heavier hot water pipes
Provide expansion loops or compensators for thermal expansion
Label all hot water pipes clearly for identification

7

Special Systems Installation

Install water treatment systems (filters, softeners) if specified
Set up booster pump systems for high-rise buildings as per design
Install grease traps for kitchen waste lines with proper accessibility
Set up water heating components if included in design
Install water meters at entry points and sub-metering as required

7. Testing & Commissioning

1

Water Supply System Testing

Conduct hydrostatic pressure test at 1.5 times working pressure (minimum 10 bar)
Maintain test pressure for minimum 2 hours with no pressure drop
Check all joints, valves, and connections for leaks
Document test results with pressure readings

2

Drainage System Testing

Conduct water test by filling stacks with water up to highest point
Perform smoke test to verify integrity of vent system
Check flow rate at each fixture drain
Verify proper trap seal at all fixtures

3

System Flushing & Disinfection

Flush entire water supply system to remove debris
Disinfect potable water system with chlorine solution (50 ppm)
Allow minimum 24 hours contact time
Flush system with clean water until residual chlorine is below 0.2 ppm
Take water samples for bacteriological testing if required

4

Final Commissioning

Verify operation of all fixtures with proper water flow
Check for proper drainage at all outlets
Confirm operation of hot water system with correct temperature (55-60°C)
Adjust all control valves, pressure reducers, and balancing valves
Verify proper operation of special systems (pumps, treatment systems)

8. Quality Control

Verify pipe materials against approved submittal before installation

Check pipe sizes, slopes, and alignments against drawings

Inspect joint connections for proper sealing and workmanship

Confirm fixture installations are level, secure, and properly sealed

Document all pressure tests with photographs and test reports

Verify compliance with local plumbing codes and standard specifications

Obtain required third-party inspections and approvals

9. Safety Precautions

Personal Protective Equipment

Gloves, safety glasses, hard hats, and safety footwear must be worn at all times

Fire Safety

Keep fire extinguishers nearby when soldering or using heat for pipe joining

Trench Safety

Follow proper shoring and access procedures for excavations deeper than 1.2m

Electrical Safety

Use GFCI protected power tools and keep electrical connections away from water

Hygiene & Contamination

Avoid cross-contamination between waste and potable water systems

Manual Handling

Use proper lifting techniques and mechanical aids for heavy pipes and fixtures

10. Common Issues & Troubleshooting

Pipe Leaks

Check for improper joint preparation, over-tightening, or expansion/contraction issues

Slow Drainage

Verify proper pipe slopes, check for blockages, and inspect venting system

Inadequate Hot Water

Check heater sizing, insulation quality, and recirculation system operation

Noisy Pipes

Install water hammer arrestors, secure loose pipes, and check for excessive pressure

Low Water Pressure

Inspect for restrictions, verify pipe sizing, check pressure reducing valves

Foul Odors

Check for dried out traps, broken seals, or incomplete venting

11. Professional Tips

Precise Layout Planning

Create detailed layout marking before cutting any chases to avoid rework

Future Access Points

Install additional cleanouts and access panels at strategic locations for maintenance

Freeze Protection

Install heat tracing and proper insulation for pipes in cold areas or exterior walls

Expansion Allowance

Use expansion loops or flexible connectors for long straight runs of hot water piping

Water Hammer Prevention

Install air chambers or commercial arrestors near quick-closing valves

Photo Documentation

Take photos of concealed installations before closing walls for future reference

12. Documentation & Handover

Prepare as-built drawings showing actual installation locations

Compile testing and commissioning reports for all systems

Collect warranty certificates and operation manuals for all fixtures and equipment

Provide photographic documentation of critical concealed installations

Conduct client/user training on system operation and basic maintenance

Provide list of recommended spare parts and maintenance schedule

13. Sustainable Practices

Install water-efficient fixtures (low-flow faucets, dual-flush toilets)

Implement greywater recycling systems where permitted by codes

Set up rainwater harvesting systems for irrigation and non-potable uses

Use renewable water heating systems where feasible to reduce energy consumption

Properly insulate hot water pipes to minimize heat loss

Install leak detection systems for early identification of water waste

14. Conclusion

Following this SOP ensures that plumbing and sanitary systems are installed with high quality, safety, and efficiency. Proper installation reduces future maintenance issues and extends system lifespan. Always prioritize code compliance, proper testing, and quality workmanship to deliver reliable plumbing systems that serve occupants for decades.

Remember that plumbing is a critical building system that affects health, safety, and comfort. Take pride in your work and maintain the highest standards of craftsmanship.

Plumbing & Sanitary Works SOP