What is the cheapest form of waterporoofing the terrace?

Hi,

Dampness causes several problems for the occupants of the building.
1. It affects the health of the person living in the building.
2. The building looks very ugly.
3. The cost of painting white washing is increased.
4. The life of the building is reduced.
Keeping in view above problems, water proofing of the terrace should be done according to the following methods.
1. Proper outlet for rainwater must be fixed.
2. Cement concrete Gola should be constructed at the junction of roof slab and parapet.
3. Proper slope should be given towards outlet for quick drainage of rainy water.
4. Two coats of bitumen should be laid on RCC slab.
5. The earth 3 inches to 4 inches should be laid on bitumen surface to make proper slope to drain rain water. 
6. Tile tracing consisting of brick tiles should be laid on one inch mud mortar on compacted earth. 
7. Cement pointing must be done on the joints of brick tiles laid in tile tracing.

Dear Sam

      The earth means ''Mitti'' from ground and this is laid for giving the slope to drain the rain water. This is laid nominal or zero at the mouth of pipe and maximum on the oter end to make slope.See the articles on the link for dampness.

http://www.gharexpert.com/category/1372/Dampness-0.aspx?PL=2&Estimator=