Question

A residential building was affected by the patches on all the walls, leakages in the corner of the building and uneven floors. Explain briefly the four methods to control the above problem mention in the building.

Answer 1

control of patches in the building:

1) using chlorine bleach- preparation of bleach solution using one part bleach and 10 parts water has to be done. For safety ereason gloves and masks should be put on. A clean absorbing cloth should be taken and dip into the solution and it should be little bit squeezed so that extra solution comes out. Now it has to be applied on the patch and wiping should be done subsequently, until the patch mark is gone. If the solution becomes dirty another solution should be prepared. Now a dry cloth is taken and put on the initial patch marks to absorb the extra moisture present there. Further top coating with special paints can be done.

Control of leakages:

2) using mastic asphalt and jute cloth- On flat roofs where inadequate slope is there, water pondage may occur which can leak through cracks, or permeate through bricks or can seep through corner joints. A layer of Mastic Asphalt is laid in hot state over the affected surface of the roof. Then jute cloth is spread over the laid mastic asphalt and again a layer of hot mastic asphalt is laid over it. This acts as a sandwitched layer and water proof layer. Now sand is sprinkled over it. To ensure more water proofing at the corners lead sheets can be applied at the junction of roof surface and parapet wall.

3) Using Bedding concrete and flooring-

The affected roof surface area near the parapet wall and roof junction should be scratched to make it rough before applying this method. On this rough area brickbats cement concrete or brickbats lime concrete with prescribed mixes can be applied.Tiles, terrazzo flooring can also be used. A convex surface has to be provided at the junction of roof and parapet wall.

4) Using membrane damp proofing and integral damp proofing-

Materials like bituminous felts, polymers, plastics,mastic asphalt etc can be used as protective membranes which prevent water to penetrate through joints, fissures and seepage.

Also during construction or preparation of fresh concrete special materials can be blended with the fresh concrete. These materials are available in the market in powder and liquid form which can be mixed with concrete ingredients. These materials inhibit leakages by improving concrete impermeability.

control of uneven floors:

5) using concrete leveller-

Concrete leveller is a very user friendly, rapid set, self leveling compound which is poured over the affected area. It is very flowable and occupies low spots on the slab as it goes along the uneven slabs. This way a new level surface is created.

For wooden slabs and beams affected by moisture and rot, bending and sinking occurs which gives uneven surfaces. This problem can be corrected using concrete or metal piles. Also when the problem is severe one may have to remove the affected wooden beams and slabs and replace with new beams and slabs.