22/EET/BSNL/TVM/2024-25

Amount

Removal of existing roof tiles and proper disposal .The entire surface area will be meticulously cleaned, removing all loose debris and contaminants using mechanical methods until hairline cracks and aggregate texture are visible. This process must ensures the substrate is adequately prepared to receive the subsequent waterproofing treatment.All as directed by the Engineer-in-charge.

Waterproofing of Terrace -Sloped roof- Methodology of Water Proofing Terrace with Polyurethane- P.U Waterproofing - Desmopol – TECHNOPOL ( SPAIN) should include the following steps:

Surface Preparation &Pressure Grouting: The entire surface area to be cleaned throughly to ensuret removing all loose particles, Cleaning of the RCC should be carried out using appropriate tools such as a hacking tool, wire brush, wire grinder and air blower etc. Open cracks and construction joints to be sealed with non-shrink grout (such as GP2 or equivalent). All visible weak points, including honeycombs and construction joints, should be treated using methods such as pressure grouting and gap filling. This process must ensure a thoroughly prepared surface, ready to receive the waterproofing treatment.

Application for anti-corrosive coating:-Clean the reinforcement thoroughly and apply an anti-corrosive coating, such as Nitozinc Primer (manufactured by M/S FOSROC Chemicals or an equivalent product). If the existing reinforcement bars have experienced a reduction in diameter of 30% or more, supplemental reinforcement shall be provided. This additional reinforcement must be securely anchored to the existing core concrete using shear connectors, ensuring structural integrity.

Pressure grouting:-Pressure grouting with non shrinking pressure grouting admixture Fosroc Cebex 100 @ 250 grams/ bag of cement at all the water dripping areas, construction joints, and other highly pores areas minimum 30 cm interval as directed by the Engineer-in-charge at site.

Covering the surface:Coving all the corners and sealing junction pipes with Acrylic Polymer Modified Cementitious SBR Latex Waterproofing Membrane - Poly Bond SBR Latex and Magno fix - with Cement and Sand then the surface will be allowed to dry .

Primer Coating 1st Coat:-Acrylic Polymer Modified Cementitious SBR Latex Waterproofing Membrane – Poly Bond & Magno fix with Cement to be applied on the prepared surface as primer coat and the surface should be allowed to dry.

Mesh Fixing Coat 2nd Coat:-All the Floor and Wall should be layered with the Fiber Glass Mesh 45gsm with Acrylic Polymer Modified Cementitious SBR Latex Waterproofing Membrane – Poly Bond & Magno Fix with Cement Mortar, on the prepared surface and the surface should be allowed to dry

Primer Coating 3rd Coat:-Acrylic Polymer Modified Cementitious SBR Latex Waterproofing Membrane – Poly Bond & Magno fix with Cement to be applied on the prepared surface as primer coat and the surface should be allowed to dry.

Main Coating 4th Coat & 5th Coat:-Apply full area with DESMOPOL from Technopol (Spin) single component liquid made up from Pure Polyurethane, which once catalyzed forms a continuous elastic membrane, without any joints, overlapping or any integrated mesh needs. It should achieve air-tightness and perfect waterproofing on a multitude of surfaces and substrates. It should be applied manually, by Brush/Roller or Airless Spry allow to dry 5 to6 hrs for further coat. Two Coat with 1.5mm thickness.

All the aforementioned steps must be executed with precision and efficiency to ensure the prevention of any potential issues.All as per the direction of Engineer-in-charge

Repairs to RCC Structural elements of framed or load bearing structure such as beams, columns, slabs, fins,facias,etc.including scaffolding up to fifth floor terrace level with following operations :-

Removing all spalling concrete/cement mortar from the body frame by tapping the debonded concrete surface beyond 2 to 3 mm from the rusted reinforcing bar completely and cleaning all the reinforement bars.

Washing the cleaned reinforcing bar with clean water and applying one coat of anticorrosive Nitozinc primer on dried bar using paint brush.Care shall be taken to see that the applied primer makes an unbroken continuous film.

After cleaning the bar,applying one coat of bonding agent Nito AR on the exposed bar and concrete surface.

Covering the exposed bar as well as the affected concrete with high protection high strength Rendroc.

Covering the surface with modified polymer mortar to the required thickness (applied in layers not more than 25mm thick ) including finishing ect. completed and as directed by the Engineer in charge.

L KRISHNANKUTTY (BID ID -797555)