(This article is specifically designed for Indian continent)
A dry basement is a fun place to have. Usually home owners do not care for proper design of the basement at the time of consutruction and face tremendous problems later on. If care is taken initially, a lot of problems can be avoided.
These methods can be applied for water proofing of basement during construction.
Basement where adequate space is available for excavation
The excavation of ground for basement is carried out in such a manner that working space of at least 60 cm is available around external walls. If water level is high, the excavated area should be kept dry by continuous pumping.
The following operations are executed in water proofing of basement.
1) On dry and leveled ground 75 to 100 mm thick lean concrete is laid to serve as a leveling course for water proofing.
2) The bitumen based primer is applied with brush on entire area at 0.24 to 0.30 liter per sq. meter after cleaning the surface.
3) Bitumen compound polyester membrane is fixed in hot bitumen of grade 85/25 at the rate of 1.5 kg. Per square meter. This layer should be protected by construction of flat brick flooring.
4) After construction of structural slab and walls, water proofing treatment on external face which is in contact with earth is done.
5) After the surface is cleaned, bitumen primer is applied.
6) Self adhesive S B S rubber bitumen membrane with high density polyethylene film is applied on vertical walls.
7) Before back filling the soil an outer protective wall leaving a space about 100 mm around should be made and the space should be grouted subsequently.
1) The base slab of lean concrete is laid followed by construction of external protective wall. Its internal face is rough plastered. Horizontal damp proofing treatment is carried out.
2) In the same manner as described in above process vertical damp proofing treatment is applied on inside plastered surface of the protective wall.
3) The treatment should be continuous on the wall and the floor.
4) For vertical damp proofing continuous with horizontal a fillet 75 mm ratios of 1:4 cement mortars should be provided at the junction of the slab and outer protective wall.
5) The horizontal and vertical damp proofing is protected against damage during subsequent operations.
6) Flat brick flooring and an inner protective wall are constructed.
7) The space of 100 mm left between vertical damp roofing treatment and internal protective wall is grouted after laying damp proofing membranes.
8) Thickness and reinforcement of RCC structural slab and walls are designed according to depth.