ESCAP Service Building Roof Repair Project at ESCAP premises, Bangkok, Thailand

The United Nations Economic and Social Commission for Asia and the Pacific (UNESCAP) is the regional development arm of the United Nations for the Asia-Pacific region, and it is headquartered in Bangkok, Thailand. We invites all potential and qualified companies to Expressions of Interest (EOI) to undertake work related to provide roof repair service at the United Nations Service Building, Rajdamnern Nok Avenue, Bangkok. The Service Building, 5 storey reinforced concrete building with one basement and one parking floor built in 1975 with a total of 19,727 sqm of constructed area. The roof area of the building is identified water leakage due to concrete failure, allowing water to collect against the outer surface and then to pass through via small fissures. UNESCAP intends to renovate the existing flat roof area to prevent water infiltration causing further damage, and to reduce heat gain through the flat concrete roof. The roof area of the Service Building to be maintained in this project is a total of 1,900 sqm. Scope of Works 1. All labour, materials, tools and other equipment, services, supervision, subcontractor required to complete all flat roof repair works as listed areas and to the full extent of the drawings and specifications.  Site Investigation a. Conduct a survey of existing conditions for all circumstances that may restrict the work. b. Verify all grades, lines, levels, and dimensions relevant to the drawing. Any errors or inconsistencies must be reported to UNESCAP before commencing work. c. Submit detailed existing conditions report for UNESCAP approval in order to demolish the designated items.  Mock-up Preparation a. Establish a mock-up to demonstrate the surface appearance, slip resistance, water leakage prevention, and other significant requirements of the waterproofing system for UNESCAP approval before commencing works. b. Conduct required testing and verification.  Surface Preparation a. Clean, rubbish and remove all dust, debris, and other contaminants on the existing surface following manufacturer requirements. b. Refurbish and repair the existing surface where cracked or damaged as technically required. c. Provide protection to all existing systems and equipment to prevent any damage during construction. d. Temporarily reroute and reinstall critical existing systems to accommodate the new waterproofing and maintain service during construction e. Re-profile of the existing surface where required to eliminate water pooling f. Replace all roof drain coverings with new ones. Submit samples of the new coverings for approval prior to installation. g. Extend the drain gutter and re-grout joints between existing drainpipe and floor drain according to the drawing. h. Apply mortar chamfer at the joints between wall, parapet and floor (vertical and horizontal surfaces). Remove portions of existing finishes to accommodate mortar filling, thereby enhancing water leakage prevention.  New Waterproofing (Overlay) a. Apply new waterproofing system, overlaying on the existing surface according to manufacture recommendations. Ensure continuous coverage from floor to roof drain, wall, parapet, plinth, and support (cover entire horizontal and critical vertical surfaces). b. All existing sealant joints shall be removed, cleaned, and remade with new sealant. c. Treat all identified areas to halt corrosion and leaching, including plinths of equipment on the roof floor. d. Conduct testing of the waterproofing systems, roof drainage performance, dampness measurement and/or all necessary works to make sure it functions properly. 2. Dispose and transport all debris, rubbish, and other waste materials resulting from construction works to off-site 3. Provide all personal protective equipment to the workers as required work. 4. Provide all documentation on work plan, personnel and responsibilities, health and safety, materials equipment, temporary work plan for approval prior to commence work. 5. Coordination with all parties such as Security Safety Section, sub-contractors and UNESCAP.