Basics of Building Construction

Basics in Building Construction 4(2+2)

Lesson 05 : Damp Proofing Treatments

Water Proofing Treatment For Roof In Multistorey Building

In case of multi-storey buildings water proofing treatment to the roof is important. The water –proofing treatment given to the roof of multi-storey building consists of the following steps.

1. Painting the top of roof slab uniformly with a layer of hot bitumen spread at the rate of 1.70 kg of bitumen per sq. m. of roof surface.
2. Spreading immediately coarse and at the rate of 0.6 cu.m. of sand per 100 sq.m. of roof surface when the bitumen is still hot.
3. Laying cinder concrete 1:15 ( 1 cement: 15 cinder of 13 mm and down guage) in an average thickness of 15 cm, the slope for the proper drainage of roof being given to this layer.
4. Laying 7.6 cm thick layer of lime concrete over the consolidated layer of cinder concrete. The lime concrete being prepared by mixing 50 % of mortar consisting of lime and sand mixed in the ratio of 1:2 with brick 25 mm and down guage.
5. Spreading 13 mm thick layer of cement mortar 1:3 and laying tile bricks flat and open jointed over the mortar. Finally grounting the joints in tile brick with cement mortar 1:3.