Contract No.: CW13214 Doc. No.
:
Date Issued: 12/2/2025 MS: Installation of drainage system under slab
Method Statement
Installation of drainage system under slab
Project: Madrasat Addeera (Art School)
Prepared By: Reviewed Reviewed By: Approved By:
Engineer By: HSE QA/QC Manager Project Director
Manager
Name: Engr Ali Ahmed Mr. Imran Mehmood Engr. Umar Iqbal Dr Hussam Ghanem
Signature:
Date: 12/02/2025 12/02/2025 12/02/2025 12/02/2025
Contract No.: CW13214 Doc. No.:
Date Issued: 12/2/2025 MS: Installation of drainage system under slab
Installation of drainage system under slab
Table of Contents
1- PURPOSE....................................................................... 3
2- SCOPE OF WORK 3
.......................................................................
3- REFERENCES ....................................................................... 3
4- MATERIALS & TOOLS REQUIRED ...................................................... 3 - 4
5- RESPONSIBILITIES………...............…………………....................... 4
6- PROCEDURE ………………….......................................... 4-6
7- Health, Safety & Environment (HSE) ………............................ 6
8- Quality Assurance & Control …………………….......................... 6
9- ATTACHMENT……………........................................................ 6
Safety Risk Assessment
Inspection Check List
1. PURPOSE:
To outline the procedure for the proper installation of plumbing pipes under the slab, ensuring
compliance with project specifications, Saudi Building Code (SBC), local plumbing codes,
and international standards, while maintaining quality and safety.
2. SCOPE:
This method statement covers the installation of plumbing pipes under the slab,
including:
Drainage Pipes (soil, waste, and vent systems)
Water Supply Pipes (cold and hot water distribution)
Sleeving and Penetrations through the slab
Testing and Quality Assurance
3. REFERENCES:
Project Specifications and Approved Drawings
Saudi Building Code (SBC 701: Plumbing Systems)
SASO (Saudi Standards, Metrology, and Quality Organization) regulations
for materials
Manufacturer’s Installation Guidelines
Health, Safety & Environment (HSE) Plan
4. MATERIALS AND TOOLS REQUIRED:
MATERIALS:
HDPE pipes (for drainage and waste systems)
HDPE pipes (for water supply systems)
Pipe fittings (elbows, tees, reducers, couplings)
Pipe hangers, supports, and clamps
Sleeves, and protective covers
Adhesives, primers, sealants, and lubricants (SASO certified)
Sand bedding, concrete, or suitable backfilling materials
TOOLS:
Measuring tape, spirit level, chalk line
Pipe cutters, reamers, and deburring tools
Fusion machine for pipes
Drilling machine and core cutters (for penetrations)
Pressure testing pump (manual or mechanical)
Safety gear (gloves, goggles, helmets)
5. RESPONSIBILITIES:
Project Manager:
Ensure timely resource allocation, approvals, and overall project compliance.
Site Engineer/Supervisor:
Monitor execution as per drawings and Saudi standards.
Plumbing Foreman:
Supervise installation crew and ensure quality.
QA/QC Inspector:
Conduct inspections and ensure compliance with SBC and project specifications.
HSE Officer:
Ensure implementation of safety measures and protocols.
6. PROCEDURE:
6.1. Pre-Installation Checks:
Review and verify the latest approved plumbing drawings and specifications.
Ensure that all materials are SASO certified and in good condition.
Confirm slab penetrations and sleeves are accurately placed according to the drawings.
Check alignment of pipe routes and verify that pipe slopes are in accordance with SBC 701.
Ensure availability of safety gear and tools on site.
6.2. Marking & Layout:
Use chalk lines to mark pipe routes on the formwork.
Ensure correct gradients for drainage pipes (minimum 1% slope as per SBC).
Mark locations for cleanouts, traps, and vent connections.
Confirm clearances from structural elements and other MEP services.
6.3. Installation of Drainage & Waste Pipes:
Use HDPE pipes for soil and waste lines.
Clean and prepare pipe ends before applying primer and adhesive.
Install pipes with the correct slope to ensure efficient flow.
Secure pipes with hangers or supports at intervals as per SBC standards.
Install cleanouts at accessible locations in accordance with Saudi Plumbing Code.
Ensure vent pipes are properly connected to prevent airlocks.
6.4. Installation of Water Supply Pipes:
Use HDPE pipes for cold and hot water distribution.
For HDPE pipes, heat-weld fittings using the correct fusion temperature.
Ensure proper alignment and avoid stress points in the piping.
Install pressure-reducing valves where required by SBC.
Provide thermal insulation for hot water pipes as per project specifications.
6.5. Installation of Sleeves:
Ensure sleeves are installed for all pipes passing through structural elements, allowing
space for expansion and contraction.
Seal around sleeves with appropriate waterproofing materials.
6.6. Testing:
Leak Test for Water Supply Pipes:
o Cap all outlets and pressurize the system with water or air to 1.5 times the
working pressure.
o Maintain the pressure for at least 2 hours and monitor for pressure drops.
o Inspect all joints and connections for leaks.
Flow Test for Drainage Pipes:
o Conduct a water flow test to ensure proper drainage and no blockages.
o Check for any leaks at joints and connections.
6.7. Inspection and Approval:
Submit the installed piping for inspection by the QA/QC team and relevant authorities.
Ensure compliance with Saudi Building Code (SBC 701) and project specifications.
Obtain necessary approvals before proceeding to the next stage.
6.8. Backfilling & Protection:
Protect pipes with soft sand or foam wrapping before pouring concrete.
Ensure pipes are not displaced during slab reinforcement and concrete pouring.
Coordinate with the structural team to avoid damage during concrete placement.
Monitor the slab pour to ensure no movement of the pipes.
7. Health, Safety & Environment (HSE):
Ensure all workers wear proper PPE (helmets, gloves, safety boots).
Follow the Saudi Occupational Safety and Health (OSH) regulations.
Secure all tools and materials to prevent trip hazards on-site.
Ensure proper ventilation when using adhesives and solvents.
Conduct regular safety briefings and toolbox talks.
8. Quality Assurance & Control
Ensure all materials used are SASO certified and comply with the Saudi
Building Code.
Maintain proper documentation of all tests and inspections.
Ensure all non-conformities are reported and rectified before proceeding.
Maintain photographic records of critical installations and tests.
9. ATTACHMENT:
12.1 Safety Risk Assessment
12.2 Inspection Check List
