Jack Arch Roof
Surface protection of jack arch roofs with cementitlous waterproofing compound incl. reinstating missing or loose tie rodsat end bays of arches (at extra cost); removing existing tarfelt and other damaged waterproofing systems; replacing soft or damaged lime terrace, if at isolated locations, with cement concrete (1:2:4); sealing cracks on the roof surface with sealing compound of acrylic-styrene copolymer having density of 0.9, pH 7.0 to 8.0 and having excellent bond & waterproofing properties and a minimum expandability of at least 200%; providing a 10 mm thick cement-sand (1:4) plaster on the entire surface; curing for 7 days; waterproofing the surface with a two-layer plaster; the first layer shall be 5 mm thick with cement (OPC or slag), admixed with an octadecanoic acid based cementitious waterproofing compound In the weight ratio of 50:3 for cement and waterproofing compound; and second layer of 12 mm thick cement-sand (1:4) plaster, enriched with polyester fibre and curing the plastered surface [polyester fibre to be paid under separate item)