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Scope Safety Material Method Equipment Attachment
Scope
This statement is aimed to propose the procedures to be adopted to carry out the operations on the proposed roofing system over the suspended slabs on buildings.
Reference documents
Drawings Nos.
Specifications, Construction practice
Safety
Prior to commencement of any activity, the labour force shall receive a STARRT Card / Toolbox Talk relevant to the operation concerned on the project site safety requirements.
Necessary measures shall be applied to any process involving a safety risk
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
A competent inspector shall visit the area daily to assess the safety measures adopted. Any snag observed during his visit shall be notified to the supervisor present who immediately act to bring the safety measures to an acceptable standard
Specialist Contractor
M / S Al Nahda Contracting and Trading Company Limited PO Box # 1053, Sharjah
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
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.
On the existing RCC suspended slab all large foundations if any, shall be constructed prior to commence any roofing system operation. A groove shall be formed around the periphery of the area, on the pad foundations and other upstands at a specified height from the slab level for tugging waterproofing membrane into the parapet with sealant applied over.
All services drains or other necessary items required to be in place prior to the roofing commences, shall be completed in all respects including grouting. The area shall be cleared and made dry.
A Civil Contractor QC 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
A Civil Contractor QC 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 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 100mm wide side and end overlaps. The dressing shall be carried out over the angle fillet and upstands properly terminating into pre formed grooves by tugging the membrane into the groove as well as rainwater outlets and around penetrations.
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.
Application on the AC foundation & upstands shall be carried out according to the details shown on the sketch
A Civil Contractor QC Inspection shall be conducted & ITP signed off
Whole surface shall be flooded with water for a period of 72 hours after plugging in all roof drains
After successful completion of the test, water shall be drained out and the membrane left to dry out. ROOF MASTER insulation boards with rebated edges 75 mm thick shall be laid over the dry membrane ensuring all areas are properly covered.
TERRAM 700-filter membrane with 100-mm overlaps shall be laid over top of the insulation boards. All small and light pre cast pedestals / foundations for the cable trays, pipe supports etc., if any, shall be loosely laid over the filter membrane.
An inspection shall be conducted by the manufacturer’s representative and all coordination 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
Concrete paviors in the form of pre cast concrete tiles 500mm x 500 mm x 50 mm shall be laid loose over ITALPROFILI PVC TILE PADS to be provided at all the intersections and at the corners as shown on the sketch. At the borders where cut tiles may be required, gravel(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 1 mm thick, 80 mm girth, cut and bent to the required profile, shall be fastened with stainless steel screws above the groove, covering and protecting the sealant all according to details.
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
Major Equipment
Mixer, Aerator, Pump
Attachment
Sketch (Typical upstands and at AC Foundation) Sub Contractor’s method Statement
Clarification regarding DERBIGUM MGP Clarification regarding Aluminium Flashing Clarification regarding 10 years guarantee Clarification regarding 72 hours water test
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