TABLE OF CONTENTS
5. DUTIES AND RESPONSIBILITIES. 3
7.2. Sequence of Construction. 5
10.1…. Risk Assessment Analysis 7
1. PURPOSE
The purpose of this Work Method Statement for Block Works (Concrete Masonry Units) is to describe in detail the procedure such as setting and lay-out plan on actual location, erection of scaffolding, mixing of cement mortar, mounting/laying of blocks and all other related activity. Inform all concerned supervisor including workers the value and importance of this activity prior to implementation. This activity should be performed with strict compliance and implementation of Safety Requirements & Procedure and project specifications to complete the work.
2. SCOPE
This Method Statement (MS) cover the Installation of concrete BLOCK MASONRY work.
3. DEFINITIONS
4. REFERENCE DOCUMENTS
- Project Specifications:
- Part A-Specification for Civil & Architectural Works Division 04-04220: Concrete Masonry Units and any material parts in the other divisions and sections.
- Drawings: As per Project Standard Drawings
- Material Approval Request
- Shop Drawings
- Approved sample.
5. DUTIES AND RESPONSIBILITIES
- CONTRACTOR project Manager shall be responsible to ensure the implementation, quality, safety and approved Shop drawing.
- CONTRACTOR Section /Site Engineer(s) shall implement/supervise the work.
- Foreman and charge Hands shall carry out work with safety requirements.
- CONTRACTOR Safety Engineer/Officer shall monitor work for safety requirements.
- QC Inspector: Responsible for monitoring daily discipline and verify that the compliance to specified quality requirements. Check the work before submit the request to company for review /approval. Submit request for inspection 24 hours before the inspection.
- The work shall be progressively offered to COMPANY for inspection and approval, in accordance with the approved ITP.
6. RESOURCES
6.1. Human Resource
- Supervisor
- Foremen
- Surveyor and Helper
- Equipment Operator
- Block Work Mason
- Steel Fixer
- Unskilled Labors
- HSE Supervisor
- Plant And Equipment
- Mortar Mixer – 1 no.
- Masonry Tools for Block Work as required (Cement Trowel, Masonry Hammer etc.)
- Block Trolley as required
- Block Cutting Machine (Electric/Manual).
- Drilling Machine+ Bit.
- Nail Gun.
- Aluminum Straight Edge – As required
- Measuring Tools – As required
- Scaffolding and Planks
- 10mm Rod for mortar thickness checking – As required
- Spirit level – As required
- Plumb Bob
- Line Dory
6.3. Material
- Concrete Block
- Dry Mix Mortar for Masonry
- Block Work Accessories
- METHOD AND SEQUENCE OF CONSTRUCTION
- General and Preparatory Works.
- CONTRACTOR shall obtain the relevant block work permits as required to commence work. Permits shall be kept at site during works in “PERMIT BOX”
- Adequate where barriers, access, sign boards, warning signs, traffic control Measures shall be provided where required. Tool box talks will be conducted every prior to start the work.
7.2. Sequence of Construction
- Method and Sequence of construction
- A- Mock –up of typical block masonry shall be constructed for each type of external and internal location to demonstrate How to fix Accessories & Quality of Material and Execution of work and written approval (through ITR procedure) shall be obtained prior to proceeding with further actual works at site.
Note; (The Mockup may be part of the permanent work at site)
- Setting Out
- The area where block are to be laid will be cleaned.
- Surveyor, Site/Section Engineer, QC Engineer shall indorse the marking for block work following the approved shop drawing. Tolerance as per the approved Shop drawings
- Execution
- Area shall be clean prior to starting work.
- First layer of blocks to be solid blocks and it should be fully set out with proper alignment.
- Around openings and sills (under windows) should be of Solid block.
- Mortar mix ratio 1:3, and to be Mix no more mortar at a time than can be used within one and half hour. Mortar not used within the one and half hour time shall be disposed off. Do not re-temper mortar
- All walls shall be built true to dimensions, plumb. All work shall be laid to line, in level courses and all individual face units shall be kept “in plane”. All unit masonry shall be laid using running bond. Joints shall run straight and plumb.
- All masonry units shall be laid in a full bed of mortar with full head joints.
All required cutting of masonry shall be done with power equipment which will produce true edges free of chipping and undamaged surfaces.
- Where fresh masonry joins masonry that is partially or totally set, the exposed
surface of the set masonry shall be cleaned and wet lightly so as to obtain the best possible bond with the new work. All loose masonry and mortar shall be removed.
- Chipping and scrabbling on concrete and columns prior to the block work.
- No more than 6 lines shall be built vertically in the same day.
- Buildings (Block wall) shall be fixed to the main structure by stainless hooks with a layer of fiberglass meshes along the width of wall, every three built lines.
- Walls built using retarder mortar shall be adequately cured for a period of not less than 24 hours before any further work on the wall can take place. The mortar beds and vertical joints shall be 10mm nominal thickness and shall not exceed 15mm.
- Other trades shall be consulted and provisions made to permit installation of their work in a manner which will avoid cutting and patching as the work progresses. Tapping of units shall not be permitted after mortar has taken its initial set. Irregular work shall be replaced with fresh mortar.
- Final cleaning of all masonry work shall be with water and fiber brushes. Any
defective mortar joints shall be cut-out, filled solidly with mortar, and tooled to match adjacent work. All surplus materials, debris, tools and equipment shall be removed from the site on daily basis.
- Joints shall be raked by 5mm to form key for plaster.
- Reinforced voids in the block work shall be filled with mortar.
- Testing for block work and the daily mortar sampling as per specification and the BS 6073 & BS 4551
- QUALITY CONTROL
- Inspection and test request (ITR) for Block Masonry will be submitted for Witness.
- Approved Construction Check Sheet will verify the completed work.
- HSE
- All worker will wear PPE (Helmet, Glasses, Gloves, Boots, Full sleeve cotton coverall as a minimum)
- Proper access (Stair with handrails and hard barricaders) shall be provided as per CONTRACTOR/ COMPANY HSE procedure.
- Refer to attached activity Risk Assessment.
- ATTACHMENTS
- Risk Assessment
- Quality Control Procedure (QCP)
- Inspection & Test Plan (ITP)
- Check List
- Specification – Concrete Masonry Unit (04220)
- ATTACHMENTS
SL NO | ACTIVITY | RISK | PREVENTIVE MEASURE |
1 | Setting up scaffolding | Struck up by falling scaffolding. Improper set-up Falling | Competent supervisorCompetent scaffoldersApproved toolsBarricadesSign boards 100%tie off with safety harness |
2 | Climbing up scaffolding | Struck by falling scaffolding. Fall injury for self and others | Using Life lineCompetent supervisorTrained workers3 point contact while climbing laddersRoutine inspectionSafe accessGreen tag |
3 | Manual handling | Back injury Spinal dislocation Hand injury Pinch points | Proper accessTrained workers100% tie off Proper techniquesGreen tag |
4 | Working at height | Falling from height Death Injury | Proper accessTrained workers100% tie off Safety harnessGreen tagSign boardsGood light |
5 | Scaffold erection and Dismantling | Falling workers during scaffold dismantling. Falling objects like steel pipes, clamps, tools and other materials Struck by flying materials | Scaffolding dismantling area to be cordoned off with barrier, etc. and warning sign provided i.e. “keep out”.All scaffold material to be lowered to the ground by rope only, not thrown down. Dismantle the scaffold don’t demolish it and applied Red tag during dismantlingAll dismantling work carried out under strict supervision of Scaffold & job supervisor. Secure hand tools in place with safety lanyardsAppropriate PPE to be worn at all the time i.e. Helmet, safety shoe, Goggles, Full body harness, etc. and attached to a strong fixing point |
7 | Emergency Response | Incident / Accident | Supervisor should know the emergency contact numbers, assembly point Standby vehicle required during working time |
8 | Mixing of Mortar and Plastering Work | Personnel Injuries Insulation of dust | Training for the Safety Officer Worker, Pre job talk. PPE |
9 | Removal of waste material after Plastering work | Stumble and fall occupational health problems | Good housekeeping, Pre job talk training for the worker |
10 | Loading & Unloading | Fall / strike against persons struck by the load. Failure of lifting Load could move out of control and strike Structures people of vessels. Unauthorized persons or vehicles can come Into the lift area. | Tag lines are to be attached to the loads being lifted and these are to be manned during lifting.Only Authorized persons will be allowed into the lifting area.Tag lines are to be attached to the load and the load is to be controlled whilst being moved.Crane movements are to be controlled by a banks man using standard crane signals.Lifting is to be planned taking recognizance of length a weight and shape of load.Inspect site & position crane accordingly.Steel plates to be placed under crane.Ground to be compacted and steel plates placed.Stacks are to be built under the direction of a competent person. |
11 | Storage | Falling of materials Stack collapse injuring people | Use proper wooden beams at proper place while stacking.Ensure the stack can support the load placed on it.Stacks may only be constructed and stripped under the supervision of a person trained and experienced in building and breaking stacks. |