8. Roof concrete

Roof Slab:

Roof concreting is considered as one of the main work regarding building construction. Whole part of decided concreting should be finished at a stretch without break. So every materials recquired should be collected prior to the concreting. Enough workers should be there. Concrete mixer and vibrator is needed. Enough water should be collected in water tanks.

• For a right roof slab concreting, we have to prepare proper concrete mix.

          The main point to bear in mind is, keep the ratio between fine aggregate and coarse aggregate             should be 1:2. In case of single or two story house the ration of concrete mix will be 1:2:4

• Never ever add excess water to mix concrete. The correct proportion of water should be like this: When we take concrete mix in a plate, it should become like a scoop. This type of mix makes the roof slab strong. If workers tries to add more water for work-ability do not allow it.

• Make sure concrete mix is properly covered around and near to the iron reinforcement. Use vibrator to move concrete everywhere evenly.

After concreting, on the next day morning watering is a must. For this we have to divide roof top into small portions by putting cement sand mix as seen in the photo. Retain water continuously for 7 to 10 days. In corners with slanting areas it is not able to retain water. In such areas put jute bags (gully bags) and wet jute bags. As we are using rock sand it will take more time to cure cement as concrete. So watering should be done very seriously to avoid concrete cracks in future.