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Scope Definitions Responsibilities Safety
Material Method Equipment Attachment
Scope
This statement is aimed to present the procedures, sequences of operations and all the other details that shall be worked on the proposed roofing system to be laid over the suspended roof slabs.
Reference documents
Drawings Nos.
Specifications, Construction practice
Definitions
PSM Project Site Manager.
CM Construction Manager.
CS Construction Superintendant FM Foreman
Responsibilities
CM shall plan and organise the works to be carried out by the specialist contractor in accordance with this Method Statement.
The Construction superintendent shall control , monitor and direct the Foreman regarding the operations as required
The Construction Foreman and the supervisor of the specialist contractor shall execute the work according to the CS direction and direct the work personnel to carry out the operations as per Site requirements.
Safety
Prior to the commencement of work, the labour force shall receive the tool box talk on the Project Site Safety requirements. Any process that is adopted which may have a particular Safety risk, shall be assessed as required as per Site conditions and shall be taken care of. In
Statements were written by Professional Eng Suraj Singh Project Manager as well as Senior Project Engineer. Most of these were approved by EPC Contractor & Company (no sketches
addition the work shall not be carried out during fast winds and dust storms. All workers shall use masks and safety glasses in addition to other PPE.
The insulation boards shall be protected from the excessive exposure to sunlight.
Specialist Contractor Materials
DERBIT PASTA, DERBIGUM UNIGUM, MGP, ROOF MASTER, TERRAM 700, PRECAST CONCRETE TILES 500 X500 X50 MM form part of MAR 046 were approved subject to the comments .
The clarification on the DERBIGUM MGP – This is the membrane flashing from the same manufacturer of horizontal membrane and is a product finished with mineral granules to make it solar reflective as well as UV resistant, shall be used for the reason that:
It is not recommended to mix a self adhesive membrane with a torch applied membrane as both are not compatible
From the experience in this climate it has been observed that the textured Aluminium faced membrane tends to delaminate after a few months if left exposed (due to the different co –efficient of expansion between the metal and the bitumen)
For the aforesaid reasons the manufacturer recommend a mineral granules faced membrane as these special solar reflective granules are spread over the bitumen while still hot and form part of the roof membrane.This flashing membrane complements the main roof membrane and with this combination on vertical exposed areas the performance is guaranteed for the specified period.
Aluminium Flashing- MAR 113 Dated 8.2.2000
It is confirmed that the proposed Aluminium Flashing for the roof upstands is a plain mill finish manufactured to BS 1470 / ASTM B 209 Alloy, H 14 mill finish
Method
The roofing system shall be carried out to the following operational sequences.
Construction of all large foundation pads if any, prior to the commencement of the system laying.
Preparing the proposed area over RCC slab, parapet walls and upstands ready by fixing in positions all roof drains, cleaning the roof etc.,
Laying the Light Weight screed using foam concrete Constructing an angle fillet around
Priming with DERBIT PASTA and applying DERBIGUM UNIGUM the water proofing membrane over the screed.
Applying flashing membrane MGP over the vertical exposed part of water proofing layer Water test for 72 hours
Laying ROOF MASTER insulation boards 75 mm thick Laying in TERRAM 700 membrane
Laying loose the precast concrete tiles 500 x 500 x 50 mm Installing Aluminium flashing as specified and approved
On the existing RCC suspended slab all large foundations if any, shall be constructed prior to commencing any roofing system operation. A groove shall be formed around the periphery of the area, pad foundations and other upstands at a specified height from the slab level for tugging the water proofing membrane into the parapet with sealant applied over.
All services drains or other necessary items required to be in place prior to the roofing starts shall be completed in all respects including grouting. The area shall be cleared and made dry.
Inspection shall be conducted.
The lightweight screed using special foam concrete shall be laid in to the following mix design to produce a density of 650 to 750 Kgs / cum
Sand / Cement: 1 / 1
Cement: 350 Kg / cum Sand: 350 Kg / cum Water: 210 Lit / cum Foaming agent: 1.2 Lit / cum
The ingredients shall be mixed using a mechanical mixer, an aerator and a pump.
The surfaces to be laid with screed shall be formed using mortar dabs to the specified profiles to 1 % slope. The foam concrete screed shall be laid in two layers to avoid settlement. The second layer shall be laid when the first has dried out followed by forming smooth finish to the required falls and cross-falls
Inspection shall be conducted
The completed screed shall be cured with fresh water for two days and thereafter, left for one day to dry out.
A cement sand angle fillet of 50 x 50 mm triangular cross section shall be formed at all directional changes.
Before laying in water proofing membrane, a coat of DERBIT PASTA bituminous primer shall be applied to all the proposed surfaces.
Once dried, laying in 4 mm DERBIGUM UNIGUM membrane shall be commenced with by full torching over the primed screed allowing 100 mm wide side and end overlaps. The dressing shall be carried out over the angle fillet and upstands properly terminating into the preformed grooves by tugging the membrane into the groove as well as rainwater outlets and around penetrations.
The exposed vertical surface of the membrane shall be protected by applying 4 mm thick MGP flashing membrane 300 mm girth, mineral surface finished, UV resistant, torched over main membrane and tugged into groove as aforesaid.
Inspection shall be conducted
The surface shall be flooded with water for a period of 72 hours after plugging in all the roof drains
After successful completion of the test, water shall be drained out and the membrane left for being dried out. The ROOF MASTER insulation boards with rebated edges 75 mm thick shall be laid over the dry membrane ensuring all areas are properly covered.
The TERRAM 700-filter membrane with 100 mm overlaps shall be laid over top of the insulation boards. All small and light precast pedestals / foundations for the cable trays, pipe supports etc., if any, shall be loosely laid over the filter membrane.
Inspection shall be conducted by the manufacturer’s representative and all coordinations made.
A warranty for the specified period of 10 years shall be issued by the specialist contractor and the Civil Contractor according to the contract requirement
The concrete paviors in the form of pre cast concrete tiles 500mm x 500 mm x 50 mm shall be laid loose over the ITALPROFILI PVC TILE PADS to be provided at all the intersections and
Statements were written by Professional Eng Suraj Singh Project Manager as well as Senior Project Engineer. Most of these were approved by EPC Contractor & Company (no sketches
at the corners as shown on the sketch. At the borders where cut tiles may be required, gravels of nominal size 15 – 30 mm filling shall be carried out to create a good aesthetic.
The membrane shall be tugged into the groove and sealed with JOINT SEAL bituminous Mastic.
Plain mill Aluminium flashing 0.90mm thick, 80 mm girth, cut and bent to the required profile shape shall be fixed with stainless steel screws above the groove covering and protecting the sealant all according to details.
Major Equipment
Mixer Aerator Pump
Attachment
#37