KOLKATTA COB ROOF PAGE 1 of 9

U.S. GOVERNMENT OWNED OFFICE BUILDING (AMERICAN CENTER) ROOF

REPLACEMENT PROJECT

STATEMENT OF WORK

DATE; JUNE 2026

1.0 BACKGROUND AND PURPOSE

1.1 The U.S. Embassy in New Delhi has a requirement to replace waterproofing on the roof of one of its office buildings at Cannaught Place. This project requires a qualified contractor to install a two-ply modified bitumen protected membrane system under thermal insulation and concrete pavers according to US standard roof industry practices.

1.2 The roof area is approximately 15,000 square feet. Contractors are advised to visit the site, verify the existing conditions and measurements as stated in this Statement of Work and Drawings A-01 – A12 to develop their proposal. Any ambiguity found later will be at the discretion of the Contracting Officer for any modification.

1.3 All materials required to complete the project, except GFM (if any), shall be provided and installed by the Contractor. Any damages to GFM due to negligence on the part of the Contractor shall be replaced at Contractor’s expense.

• Secondary Roof Ply:

o 3mm thick smooth APP modified bitumen; “STP“ by Shalimar Tar Products

• Base & Top Ply:

o 4mm thick smooth APP modified bitumen; “STP“ by Shalimar Tar Products

• Flashing Top Ply:

o 4mm thick granule APP modified bitumen; “STP“ by Shalimar Tar Products

2.0 GENERAL REQUIREMENTS

2.1 Contractor shall provide personnel, material, equipment, and supervision to complete the technical requirements in this Statement of Work. Contractor shall follow security and safety directions as explained by the COR.

2.2 Contractor shall have limited access to or be admitted into the building outside areas designated for the project except with permission by the COR.

2.3 There is a possibility that work may get disrupted at times, initially during the demolition phase due to noisy work.

2.4 Any damage that occurs to the building, equipment, furnishings or landscaping due to the failure of Contractor to properly protect and secure the work site while the roof project is in progress shall be Contractor’s responsibility to repair or replace the damages that have taken place matching to existing at Contractor’s expense.

3.0 SCOPE OF WORK

3.1 Contractor shall be required to prepare reports, bill of materials, quality control schedules and construction costs. These documents shall provide the necessary interfaces, coordination, and communication among the Embassy, Overseas Buildings Operations [OBO], and Contractor for the delivery of a complete roof replacement project.

KOLKATTA COB ROOF PAGE 2 of 9

3.2 Pre-Construction Submittals: Contractor shall submit all cut sheets, brochures and material samples as specified for approval before use on the project:

• Sample Warranties STP & Contractor

• Bituminous Primer STP or equivalent

• Concrete Foam Blocks Local

• Slip Sheet Local

• Drainage Board Texsa or equivalent

• Extruded Polystyrene Insulation DOW or equivalent

• Filter Fabric Texsa or equivalent

• Concrete Paver Local

• Stainless Steel Flashing Local

• Aluminum Termination Bar Local

• Fasteners (screws & nails) Local

• Sealants Sika or equivalent

• Elastomeric Coating Synroof

3.3.1 Storage Area:

• The Embassy will provide a storage area for the Contractors to use on the Compound in Annex Building. Location will be shown at the time of walkthrough.

• All materials shall be delivered in sealed conditions on site and shall be opened in front of the COR.

• Contractor shall barricade the designated storage area and the area around the construction lift and details as followings:

o Use galvanized 24-gauge metal corrugated sheets with proper metal supports for barricading purpose. Height of the barricade should be 2.5 meters (8 feet) from the existing floor level.

o All the material, for the purpose of the barricade, should be in good condition.

Rusted and damaged material will not be allowed for use.

o Provide and install necessary self-supporting metal supports for the barricade.

o Do not drill holes in the existing driveway paving or to use any of the existing structure as a support for the barricade.

3.4 Demolition:

• Contractor shall demolish and remove the existing waterproofing layers; existing concrete support structures as shown at the time of the pre-proposal walk through.

• Contractor shall be responsible for correcting any potential damages that can occur to the existing roof slab during demolition and the duration of the project.

• The entire roof shall be cleaned of demolished material, dust, and any other kind of foreign material before proceeding with the installation of the new waterproofing system.

• Contractor shall be responsible for the security of all the existing wires & existing services (to be retained) on the roof during demolition phase. Any damages shall be repaired or replaced matching to existing at the Contractor’s expense.

3.5 Debris Removal:

• Contractors shall dispose the demolished material in such a manner so that recyclable material can be recycled. Once the project begins the Embassy will designate a place for the Contractor’s crew to separate materials such as wood, metals, masonry rubble, glass and cardboard. Contractors shall identify local companies that recycle the materials generated to the greatest extent possible.

• Contractors shall take all necessary precaution / protection and obtain approval from local authorities for disposal of debris.

• Contractor shall dispose off all the debris from the Residential Compound and keep the site clean and in workable condition throughout the project duration.

KOLKATTA COB ROOF PAGE 3 of 9

3.6 Roof System Warranties:

• Roofing Material Manufacturer’s Warranty: New roofing material shall be installed in such a manner that the roof system manufacturer shall furnish a written warranty agreeing to replace or repair defective materials including the tapered lightweight concrete, leakage of water, abnormal aging or deterioration of materials and other failure of the materials to perform within warranty period. Warranty period is 10 years after date of written final acceptance.

• Contractor’s Workmanship Warranty: Furnish a written warranty agreeing to repair or replace defective installation and workmanship causing leakage of water, deterioration of materials and other failures of the installed system, sealants, painting, coatings, and related work on this project, to perform within the warranty period.

Warranty period is 10 years after date of the written final acceptance.

3.7 Penetron Coating

3.7.1 Once demolition is done and mother slab is exposed, contractor shall apply coat of

PENETRON coating per manufacturer recommendations. Once the penetron coat is applied, ponding test to be conducted to 24 hours to ensure coating is working efficiently.

3.8 Secondary Waterproofing System - Smooth Surface Base Ply:

• Upon successful completion of ponding test above penetron coating, Contractor shall apply a coat of primer on the thoroughly cleaned deck. The primer shall be spread at a nominal rate of 3.8 liters (1 gallon) per 9.29 square meters (100sf.).

• Bituminous Primer:

• Consistency Brushable or Sprayable

• Setting time 24 Hours at normal application

• Flash point Above 40 degree

• Specific Gravity 0.9

• Manufacturer STP or equal

• Contractor shall install the secondary roof ply in one layer of 3.0 mm smooth modified bitumen membrane roofing to the Main RCC Slab. Follow the Membrane Installation for Smooth Surface Base Ply procedures for torched applied membrane as specified below.

• Temporarily seal all roof drains in preparation of light weight concrete topping.

3.8 Lightweight Concrete Sloped Topping:

• Over the secondary waterproof ply Contractor shall place foam concrete blocks and a layer of light weight concrete to create slope. The slope of this layer shall be 21mm in one meter (1/4-inch per foot) or 2% slope towards the existing roof drains.

• Cement: Pozolona Portland

• Aggregate: Exfoliated Vermiculite Granules.

• Density (Dry – 220 Kg / Cum) Plus / minus 5% (Wet – 450 Kg/Cum) Plus / minus 5%

• Thermal conductivity (applied) – 0.058 K cal / hr m deg C (tested as per IS 3345)

• PH value 7.0

• Mix aggregate and cement in a 6:1 mix ratio, six parts vermiculite and one part cement or as recommended by manufacturer, with potable water to achieve a wet density ranging from 608 to 768 kg/m3 (38 to 48 pcf)) resulting in a minimum dry density of 480 to 608 kg/m3 (30 to 38 pcf) and minimum compressive strength of 1.38Mpa (200psi).

• Contractor shall install a cementitious cant at the junction of parapet wall and roof slab to have additional protection for the wall and roof junction joint. The thickness of the lightweight concrete will not be less than 25mm (1-inch) at any point.

• Light Weight Concrete Dry-out Acceptance Test:

KOLKATTA COB ROOF PAGE 4 of 9

• Contractor shall allow light weight concrete a minimum of 7 to a maximum of 28 days to cure.

• Securely place, by taping down, a 300mm x 300mm x 6 mil clear polyethylene sheet to the lightweight concrete and observe for condensation on underside of polyethylene in 4-hour cycles. Roof asphalt primer shall be applied once no condensate is observed.

3.9 Roof Drainage:

• Contractor shall install new roof drains. The roof drain shall be placed level with the structural deck and provided with a 600mm x 600mm sump area, then begin the minimum 25mm thickness of lightweight concrete.

• Contractor shall modify existing roof drains for the new waterproofing system. Prime all metal components in direct contact with the roof membrane prior to installation.

The Contractor shall follow the manufacturer’s recommendations for membrane ply insertion under the retaining ring of the drain hub.

• Contractor shall provide new drainage on the roof of the staircase in Phase II roof.

Provide and install a 100mm diameter PVC pipe (10 Kg pressure rating) and associated bends, tees and/or elbows etc. to act as roof downspout from the roof of the stairwell in the front side of the building.

3.10 Membrane Installation - Smooth Surface Base Ply:

• Once the lightweight concrete is completely dry provide a coat of the primer on the entire roof area including vertical sides of parapet wall up to the reglet (wherever required per site conditions). Prime the top and bottom of the metal flanges and concrete and masonry surfaces with a uniform coating of bituminous primer, at a nominal rate of 3.8 liters (1 gallon) per 9.29 square meters (100 sf.).

• Unroll base ply prior to installation and cut into 5 meter (15 feet) lengths. Allow membrane to relax prior to application.

• Align side lap of base ply over mid-point or center of roof drain.

• Prior to application, re-roll “relaxed” membrane approximately 2.5 meters (7-feet 6-inches). Lay all layers of roofing free of wrinkles, creases, or fishmouths. Exert sufficient pressure on the roll during the application to ensure the prevention of air pockets.

• Apply heat evenly across the face and full width of the roll while unrolling roll uniformly with an even downward pressure. Apply torch flame to the roll until the bitumen back coating reaches the design application temperature, resulting in melting of the burn-off film, a glossy appearance of the back coating, and an approximate 6mm (1/4-inch) to 13mm (1/2-inch) bitumen flow from the edge of the sheet. Repeat this process with the other end of this 5 meter (15feet) roll.

• Overlap the side laps a minimum of 100mm (4-inches) and end laps a minimum of 200mm (8-inches). Stagger end laps of adjacent sheets of membrane base ply a minimum of 1 meter (3-feet). Extend field sheet of membrane base ply to top edge of cant.

• Check lap seams and seal unbonded or discontinuous seams using a heated steel trowel.

• Complete membrane base ply application over respective roof area prior to membrane top ply. Apply additional plies, as needed, in low areas or areas that maybe subjected to ponding water.

3.11 Base Flashing Application – Smooth Surface Base Ply:

• Install and complete application of the base ply of flashing each day the base ply of roof membrane is installed.

• Install first ply of base flashing extending horizontally a minimum of 150mm (6-inches) on to modified bitumen sheet roofing and vertically a minimum of 150mm (6-inches) above the top of the cant.

KOLKATTA COB ROOF PAGE 5 of 9

• Length of base flashings will be a maximum 2 meters (6-feet). Lap ends of base flashings 100mm (4-inches) minimum. Seal top edge of base flashing daily with a continuous troweling of elastomeric roof cement.

• Check lap seams and seal unbonded or discontinuous seams using a heated steel trowel.

3.12 Top Cap Membrane Installation - Smooth Surface Top Ply:

• Unroll top ply prior to installation and cut into 5-meter (15-feet) lengths. Allow membrane to relax prior to application.

• Align top ply centered over roof drain openings.

• Prior to application, re-roll “relaxed” membrane approximately 2.5 meters (7-feet 6-inches). Lay all layers of roofing free of wrinkles, creases, or fishmouths. Exert sufficient pressure on the roll during the application to ensure the prevention of air pockets.

• Beginning at the low point of the roof (roof drain) fully adhere membrane top ply to membrane base ply. Extend membrane top ply to top edge of cant. Stagger side laps of top ply a minimum of 300mm (12-inches) from side laps of base ply.

• Apply heat evenly across the face and full width of the roll while unrolling roll uniformly with an even downward pressure. Apply torch flame to the roll until the bitumen back coating reaches the design application temperature, resulting in melting of the burn-off film, a glossy appearance of the back coating, and an approximate 6mm (1/4-inch) to 13mm (1/2-inch) bitumen flow from the edge of the sheet. Repeat this process with the other end of this 5-meter (15-feet) roll.

• Roof Drain: Install top ply centered over roof drain opening extending under the clamping ring. Install clamping ring and secure.

• While installing membrane top ply, provide proper protection or method during application to prevent burning or charring on the surface of previously installed sheet.

• During end lap application, trim the inside corner along the selvage edge of the underlying sheet at the end of the roll. The trimmed area shall be the width of the selvage edge and extend downward from the end of the roll to the outer side of the roll on a linear direction approximately 138mm (5 ½-inches) from the end of the roll.

Trim outside corner of membrane top ply at end laps to provide a rounded finished corner.

• Overlap the side laps a minimum of 100mm (4-inches) and end laps a minimum of 200mm (8-inches). Stagger end laps of adjacent sheets of membrane tope ply a minimum of 1 meter (3-feet). Extend field sheet of membrane top ply to top edge of cant.

• Check lap seams and seal unbonded or discontinuous seams using a heated steel trowel.

3.13 Base Flashing Application – Granular Surfaced Top Ply:

• Apply top ply of flashings only after membrane is in place.

• Cut the flashing from the rolls using selvage edge as lap seam for adjacent sheets resulting in sheet lengths of nominal 1 meter (3-feet). Stagger laps from laps of underlying plies.

• Cut the granulated flashing membrane to extend to the saw cut reglet in the concrete walls at 450mm (18-inches) high from the existing top level of the roof slab.

• Extend the flashing membrane horizontally a minimum of 200mm (8-inches) onto the field of the roof surface beyond the bottom edge of the cant strip.

• Fully adhere and conform top ply of flashing to substrate. Extend bleed-out of applied base flashing a minimum of 13mm (1/2-inch) beyond the side or end lap. Embed granules, color to match to ply, in bleed-out of granulated sheets.

• Walls: Mechanically attach the top edge of the modified bitumen membrane flashing with appropriate fasteners and termination bar. Fastener spacing shall be 150mm (6-inches) on-center. Apply three-coursing consisting of an initial continuous troweling of

KOLKATTA COB ROOF PAGE 6 of 9 elastomeric plastic roof cement, embedded reinforcing fabric, and a secondary application of elastomeric plastic roof cement along and concealing the top edge of base flashing and termination bar.

• Apply membrane top ply and terminate at the rise in the metal component. Apply a continuous bead of edge sealant or molten modified compound along edge terminations of modified bitumen sheet (i.e. flashing flanges, exhaust vents, metal edge, etc.). Bead of edge sealant shall match height of granule surfacing and shall be “canted” to shed water. Embed loose granules, color to match to ply, into newly installed edge sealant.

• Curbs: Mechanically attach the top edge of flashing with appropriate fasteners and termination bar and secure 150mm (6-inches) on-center. If flashing sheet is wrapped over top of curb, secure to top or inside of curb with appropriate fasteners. For curbs with non-removable hoods/covers/units, extend flashing to full height of curb and apply three-coursing of plastic roof cement and reinforcing fabric. For curbs with removable hoods/covers/units, wrap flashing sheet over top of curb and secure to top or inside of curb with angle termination bar and appropriate fasteners spaced at 150mm (6-inches) on-center.

• Install flashing sheets on adjoining perpendicular sides (outside corners) of curbs or walls so that outside corners of flashing membrane sheet align and are rounded.

• Apply a boot or oval section of modified bitumen sheet over outside corners of curb flashings to conceal cuts in flashing material at corner laps.

• Apply a three-coursing of elastomeric plastic roof cement and reinforcing fabric at vertical lap seams. Extend three-coursing under termination bar. Utilize masking or duct tape to create vertical straight edge of three-coursing. After application of three-coursing, remove tape. Embed granules into plastic roof cement, immediately after application, to achieve uniform base flashing color.

3.14 Metal Flashing:

• Contractor shall provide a saw cut reglet in the concrete walls at 450mm (18-inches) high from the existing top level of the roof slab to accommodate the new protective stainless-steel flashing to be installed over the bituminous felt (as required per site conditions).

• Contractor shall make sure that the reglet for the flashing is straight cut and evenly distanced from every point of the original roof slab.

• Contractor shall provide and install the flashing metal edge using 22-gauge stainless steel sheets for the fabrication of the metal edge.

• Contractor shall use self-tapping stainless-steel screws 6mm (1/4-inch) dia. x 38mm (1 ½-inches) long with stainless steel washer and integral rubber seal 25mm (1-inch) wide.

• Contractor shall provide and install continuous 25mm x 3mm aluminum termination bar to secure base flashings. Termination bar shall be secured 200mm on center with self-tapping, stainless steel screws 6mm (1/4-inch) dia. x 38mm (1 ½-inches).

• The counter flashing shall be made with 22-gauge stainless steel sheet. Counter flashing will be secured to the wall with self-tapping, stainless steel screws 6mm (1/4-inch) dia. x 38mm (1 ½-inches) long with stainless steel washer at 150mm (6-inches) on-center. The gap remaining between the counter flashing and the reglet will be filled with bituminous mastic.

3.15 Slip Sheet and Drain Board:

• Contractor shall cover the newly laid modified bitumen membrane with 300-micron polyethylene sheet.

• Contractor shall provide and install PVC drain board above the polyethylene sheet.

o Manufacturer: Drentex Protect 50 by Texsa o High Density Polyethylene (HDPE) o UV resistant

KOLKATTA COB ROOF PAGE 7 of 9 o 0.5 mm thick sheet o Fire resistant (B2 DIN 4102) o Thermal Stability (-40 to 800 C)

3.16 Extruded Polystyrene Insulation:

• Contractor shall provide and install inter lockable Extruded Polystyrene Insulation.

The insulation will be applied in parallel rows and all sides/end joints will be installed closely but not forced.

o Manufacturer: DOW “SL–Shiplap” o Closed cell and homogeneous structure o Low Thermal Conductivity – R10 o Density :32 – 354 Kg/cum o Thickness; 50mm

3.17 Filter Fabric:

• Contractor shall provide and lay filter fabric over the extruded polystyrene insulation.

o Manufacturer; TERRAM 500 o Nonwoven Polypropylene and Polyethylene based heat welded geotextile.

o Tensile Strength: 3 KN/m o Elongation: 35% o CBR puncturing strength: 525N o Permeability: 150 Ltr/sq.m/sec

3.18 Concrete Pavers:

• Contractor shall provide and install concrete pavers as ballast over the roof assembly in one continuous process from slip sheet to paver.

• The paver shall be made with 1:1-1/2:3 ratio concrete with welded mesh in center of concrete for reinforcement. Each paver shall be 300mm x 300mm x 38mm (12-inches x 12-inches x 1 ½-inches).

• Aggregate for pavers shall use 3/8” stone (Jeera Rodi). The pavers shall be properly cured before lying. For curing, each paver shall be dipped in water for a minimum of seven days.

• Pavers shall be placed 1 meter center to center through out the roof.

3.19 Elastomeric Coating on Exposed Surfaces:

• The Contractor shall remove any loose plaster and repaired matched to existing with 1:4 cement fine sand mortars.

• The Contractor shall paint entire inside exposed parapet walls in the work area with one coat of cement primer and two coats of elastomeric paint to match the existing paint after the demolition work of the existing waterproofing system is completed.

• After completion of the project the Contractor shall touch up the painted areas.

• The Contractor shall protect the entire newly laid waterproofing system against splatter of paint while touching up the walls.

3.20 Miscellaneous Painting:

• Repair and renovate existing non-ferrous rooftop and metal system sheet metal fabrications as required for permanent watertight installation.

• Paint all exposed ferrous metal and sheet metal with metal primer at end of project.

• Rust Inhibitive Primer: 100 percent acrylic resin primer. Color; Aluminum

3.21 Rooftop Equipment:

• Move and elevate air conditioning units and other rooftop equipment as required to install roofing materials complete in accordance with specifications.

• When units or equipment are to be moved, disconnect, and move to protected area to prevent damage to parts or components. Reset and reconnect at Contractor's

KOLKATTA COB ROOF PAGE 8 of 9 expense.

• Disconnection and reconnection shall be performed by mechanical and/or electrical company licensed to perform such work and approved by the COR.

4.0 RESPONSIBILITY OF THE CONTRACTOR

4.1 The Contractor shall be responsible for the professional quality, technical accuracy, and the coordination of all construction and other services furnished under this contract. The Contractor shall, without additional compensation, correct or revise any errors or deficiencies in its construction and other services.

4.2 The Contractor shall identify and appoint a Project Manager who should be qualified and have experience in the field of similar projects for the management of this Contract.

Project Manager shall always be present on the site. He/She shall be able to speak and write the English language.

4.3 The Contractor shall comply with all local labor laws, regulations, customs and practices pertaining to labor, safety and similar matters. The Contractor shall promptly report all accidents resulting in lost time, disabling, or fatal injuries.

4.4 All expenses towards mobilization at site and demobilization including bringing in equipment, workforce and materials, profit and overheads, dismantling the equipment, clearing the site etc. should be included in the rates quoted by the Contractor. No separate payment on such expenses shall be entertained.

4.5 The Contractor shall provide and use LPG gas for heating of Bitumen. Under no circumstance will wood be allowed for heating the bitumen.

4.6 Contractor shall provide the necessary scaffolding, overhead protection barriers, construction lift, debris chute and associated equipment for the satisfactory completion of the project.

4.7 The Contractor should arrange for the site visit of the professional in his field from the manufacturer of materials used in this project that will be providing warranties to supervise the project during work in progress.

5.0 SECURITY CLEARANCE

5.1 After Contract Award: Contractor shall collect security forms within 2 days from the

Embassy. Contractor shall complete two types of forms for their cleared workers and daily workers. The cleared workers will escort the daily workers. Forms should be filled with residence proof, date of birth, place of birth and photograph. Duly filled forms shall be submitted to the Embassy within 10 days. It takes approximate 15 days to provide the security clearance. A Notice to Proceed cannot be issued unless security clearance is obtained.

5.2 The Contractor shall inform and provide in writing transportation details (vehicle registration number, drivers name and date of delivery) to the Embassy at least 24 hours in advance for all material and equipment deliveries.

6.0 SAFETY

6.1 Contractor is responsible and shall continue management and implementation of a safety and health program through out construction.

6.2 The Contracting Officer and the Post Occupational Safety and Health Officer [POSHO]

KOLKATTA COB ROOF PAGE 9 of 9 reserve the right to suspend work when and where Contractor's safety and health program is considered to be operating in an inadequate or non-complying manner.

6.3 Fire extinguishers shall be kept on site at all times during torch applied installations.

6.4 Contractor shall provide all Personal Protective Equipment for the workers as per the requirement of the site. Work will be stopped in case the proper protection equipment is not found with the workers and the lapse of time shall be at the Contractor’s expense.

7.0 PERIOD OF PERFORMANCE

7.1 Contractor shall submit crew security forms, construction bar chart of complete project schedule and material product data after Contract Award.

7.2 Working hours shall be 8:00 AM to 5:00 PM Monday through Saturday. No work shall be done on Sundays and holidays unless otherwise approved.

7.3 Milestones:

Pre-proposal Site Visit: …………………………… Pre-Construction Submittals Within 10 days of Award Notice to Proceed: Within 10 days of Submittal Approval Construction: 90 days on-site

[Includes 28-day lightweight concrete dry-out period] Final Clean-up and Acceptance: Within 10 days before Completion

END OF STATEMENT OF WORK