PREVENTION OF CRACKS AND LEAKS

Prevention is always better than cure. So in addition to proper design, planning and execution, proper control is necessary at every stage of construction.

1. Porous materials, which are likely to shrink on drying, should be avoided. Bricks should be exposed for 2-3 weeks after burning and soaked well before being used in the structure.
2. Fine sand, clay and silt should not be used.
3. In mass concreting, heat of hydration should be controlled.
4. Use of very rich cement mortar, which has high drying shrinkage, should be avoided.
5. Shrinkage cracks can be reduced to a great extent by keeping the water–cement ratio minimum.
6. Large spans of slabs and windows should be avoided.
7. The foundation strata should be well prepared so that differential settlement of foundations is avoided. Proper type of foundation suitable for the type of soil and its bearing capacity should be adopted.
8. It must be ensured that there is no presence of organic matter, brickbats, debris, etc. in the soil.
9. Curing of masonry and concrete should be proper.
10. In RCC-framed structures, panel walls should be constructed from top downwards.
11. Joints for movements should be provided as per standards especially at the change of directions.
12. Plastering on panels and partitions should be delayed as far as possible whereas plastering on concrete is to be done as early as possible.
13. Sufficient bearing length should be provided for lintels to avoid cracks due to stress concentration.
14. Concrete in the marine atmosphere has to be made dense with sufficient cover thickness to avoid corrosion of steel.
15. Differential loading on the foundation should be avoided during construction.
16. Roots of trees removed for construction should be made to dry out before construction is taken up.
17. In concrete utmost care should be taken to avoid entrapped air and segregation of materials. In order to attain these, it should be ensured that the concrete mix possesses good workability and cohesiveness.
18. Before tampering or modifying a concrete or masonry structure (for extensions, modifications or even for providing embedded service conduit for electrical, water and drainage lines) all the aspects should be taken care of.
19. Blended cement, minerals and chemical additives, etc. have a significant role to play in durability and so their use should be encouraged. Water proofing agents can be mixed with roofing concrete.

It is essentially because of ignorance, carelessness, greed and negligence that the failures occur. So utmost care must be there in dealing with all the factors mentioned above.