The purpose of this civil work method statement is to define the procedure of the waterproofing works for underground water tanks and basement in accordance with the requirements specified in the relevant specifications, procedures and drawings, considering safety and quality of the work activities.
Scope of this method statement is for the water proofing works of pile cap, water tank wall and penetration to the underground walls.
Below is list of materials to be used, brand names are given for reference only.
- Epoxy Masterflow 410 PCT-for pile head repair
- VERNIS ANTAC ST-Bituminous primer from Axter UK
- FORCE 4000 S- SBS elastomeric modified bituminous waterproofing membrane made by Axter UK
- Bituminous Primer: Axter-VERNIS-ANTAC-ST
- SBS membrane: Axter force 4000 line SBS 4mm thick
- Polyethylene sheet
- Protection board 3.2 mm thick
- Masterflow 410 PCT
- Axter Proofcoat Latex seamless membrane
- 50 mm wide Aluminum flashing
- Screed (C 20 N/mm2)
List of Human Resources for the Work
- Project Manager
- Construction Manager
- Project Engineer
- QA/QC Engineer / Inspector
- Safety Engineer/Officer
- Foremen/Work Supervisor
- Equipment Operators
- Skilled and unskilled labourers
Note: Quantity of manpower, equipment and materials will be submitted on the daily progress report.
PILE head Treatment
After demolishing the pile head to reach the cut off level, the pile head and the last 300 mm of the pile will be reprofiled and repaired by the approved repair material.
300 mm wide Axter Force 4000 line, 4 mm thick SBS membrane will be torch applied around pile head and fully bonded to one coat of primer.
The blinding around the pile will be casted and waterproofed as above.
Overlap between blinding waterproofing to the pile head shall be applied as per the approved detail.
2 coats of Axter Proofcoat latex seamless membrane will be applied to the full area of the pile head. Each coat is 1 kg/m2, Second coat at right angle to the first coat.
Shutter will be done for the pile head to pour 20 mm thickness of Epoxy Masterflow 410 PCT.
Masterflow will be mixed, placed and cured as per the manufacturer recommendations which is shall be attached/provided with this method statement.
Horizontal Waterproofing for the blinding of basement
Concrete surface of the blinding will be free from ridges and grinder will be used to remove any signs of trowel to maintain an even surface.
Fillet angle will be provided at corners to facilitate dressing of waterproofing.
Concrete surface of the blinding will be cleaned prior to applying the primer.
Bituminous Primer will be applied to the horizontal blinding concrete surface at a rate of 350 g/m2.
The bituminous primer will be allowed to dry completely.
Membrane strips with minimum width of 300 mm will be applied at corner joints.
First layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to primed concrete surface.
Second layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to first layer.
Overlap of the membrane shall be minimum 100 mm in longitudinal direction and 150 mm in transverse direction as per manufacturer recommendations.
The membrane will be free from any defects.
Membrane will extend 400 mm behind the plot of the tank (see waterproofing details).
Polyethylene sheet will be laid over the membrane.
Concrete screed type C 20 N/cm2 will be casted as a protection with minimum thickness of 50 mm.
Vertical Waterproofing for Basement Walls
Surfaces of concrete walls shall be even and free from any imperfections.
Surfaces of concrete walls will be cleaned prior to primer application.
Bituminous Primer will be applied to the concrete surface at a rate of 350 g/m2.
The bituminous primer will be allowed to dry completely.
Membrane strips with minimum width of 350 mm will be applied at corner joints.
First layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to primed concrete wall surface.
Second layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to the first layer.
The overlap of the membrane shall be minimum 100 mm in longitudinal direction and 150 mm in transverse direction as per manufacturer recommendations.
The membrane applied will be free from any defects.
Bituminous protection board 3.2 mm thickness will be fixed by torch spot bonded method over the above mentioned “Axter Force 4000 Line SBS membrane”.
50mm wide aluminium flashing with mastic will be applied for termination of waterproofing.
Concrete screed type C 20 N/mm2 will be casted as a protection with min. thickness of 50 mm to the exposed 40 cm behind the basement wall.
Waterproofing for blinding of Under Ground Water Tank
Concrete surface of the blinding will be free from ridges and grinder will be used to remove any signs of trowel to maintain an even surface.
Fillet angle will be provided at corners to facilitate dressing of waterproofing.
Concrete surface of the blinding will be cleaned prior to the application of primer.
Bituminous Primer will be applied to the horizontal blinding concrete surface at a rate of 350 g/m2.
The bituminous primer will be allowed to dry completely.
Membrane strips with minimum width of 300 mm will be applied at corner joints.
First layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to primed concrete surface.
Second layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to first layer.
The overlap of the membrane shall be minimum 100 mm in longitudinal direction and 150 mm in transverse direction as per manufacturer recommendations.
Membrane should be free from any defects.
The membrane will extend 400 mm behind the plot of the tank (see waterproofing detail).
Polyethylene sheet will be laid over the membrane.
Concrete screed type C 20 N/cm2 will be casted as a protection with minimum thickness of 50 mm.
Treatment of Vertical Areas and around Pipe penetration of Under Ground Water
Surfaces of concrete walls shall be even and free from any imperfections.
Surfaces of concrete walls will be cleaned prior to primer application.
Bituminous Primer will be applied to the concrete surface at a rate of 350 g/m2.
The bituminous primer will be allowed to dry completely.
Membrane strips with minimum width of 350 mm will be applied at corner joints and around pipe penetrations.
First layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to primed concrete wall surface.
Second layer of Axter Force 4000 line SBS 4mm thickness will be torch applied and will be fully bonded to the first layer.
The overlap of the membrane shall be minimum 100 mm in longitudinal direction and 150 mm in transverse direction as per manufacturer recommendations.
The membrane applied will be free from any defects.
Bituminous protection board 3.2 mm thickness will be fixed by torch spot bonded method over the above mentioned “Axter Force 4000 Line SBS membrane”.
Concrete screed type C 20 N/cm2 will be casted as a protection with min. thickness of 50 mm to the exposed 40 cm behind the water tank wall.
ATTACHMENTS
- Inspection Checklists
- Inspection and Test Plan
- Risk Assessment
- Technical Data sheet (TDS)
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