WBMAD/NDITA/36/2021-22 /1

Amount

Water proofing work for about 05m height Basement Floor of the existing Administrative Building of Nabadiganta Industrial Township Authority at Plot No. GN-20, Nabadiganta Industrial Township, Kolkata-700091.

Scope of work: a) Dewatering and cleaning of the basement floor. b) Detection of the defective spots / locations out of the floor from where sub-soil water is ingressing into the basement. c) Removal of plastering from the damped area of the wall. d) Detection of the defective spots / locations out of the wall from where sub-soil water is ingressing into the basement. e) Making V-grooves at the junctions of wall and base slab and along the crack lines, if any. f) Sealing of the V-grooves with polymer mortar or epoxy mortar, as suitable. g) Drilling and making holes within concrete at suitable points in wall and floor and fixing of the nipples for grouting work. h) Grouting the soil adhere to the contact face of the wall and floor slab might be needed to prevent water ingress within the basement and that work is to be performed with due care. i) OPC slurry / MFC slurry (as needed for the work) with different consistencies and at a very low to low pressure is to be grouted through the nipples, already fixed. Suitable nonshrinkage- easy flow admixture will be added with OPC slurry for grouting work. j) Epoxy grouting may be required to seal fine crack lines and fine pores within concrete. k) All nipples are to be taken out and the holes is to be sealed with suitable polymer mortar or with epoxy mortar. l) Re-plastering to be done on the removed plastering areas after application of atleast two coats of branded cement-based polymer modified water proofing slurry. m) In case of poor concrete area, if anywhere observed, patch repair work is to be done with polymer concrete after removing the loose concrete. n) Application of cement – latex slurry bond coating is needed before laying of concrete and plaster on the prepared surfaces of wall and floor slab of the basement. Epoxy bond coating should be done in some areas, if needed. o) Entire basement area to be cleaned on completion of complete water proofing job.

AMAL DUTTA ROY

PARTHA PRATIM BISWAS