Author: haroonkhan

1. Merits 2. Demerits

It is one of the basic requirements of flat roofs. The rain water should be drained off quickly so as to avoid leakage of roof. In order to achieve this satisfactorily watertight roof surface, adequate slope and drain outlets have to be provided. The slopes in flat roofs vary from 1 in 20 to 1…

The flat roof should be made waterproof by a surface covering. The following methods are employed: 1. Cement Mortar Finishing For small buildings or normal use, the finishing of roof surface is done at the time of laying cement concrete. The flat roof is finished with cement mortar of 1 : 4. 2. Bedding Concrete…

Flat roofs are provided with a weather-proof course to sustain the effects of atmospheric agencies. The construction of waterproof course consists of providing one course of surki-concrete and two courses of flat tiles. The surki concrete (broken brick aggregate and lime with no sand) in the mix ratio of 1: 2 : 5 is laid…

This type of roof, although oldest, is cheap and fairly water-tight. It is still used in villages where the rainfall is light. This mud terrace is constructed out of good white earth containing a large percentage of sodium salts.

The construction of Jack arch flat roof is similar to the construction of Jack arch floors. The covering or terracing may be a 10 cm thick layer of lime concrete to make the roof water tight along with some waterproofing material. Alternatively the covering may consist of a 10 cm thick earth filling which is…

This type of roof is used especially used in Bengal to cover verandahs and so get the name as Bengal Terrace Roof. This type of roof consists of rafters, battens, flat tiles and final finish. At first the rafters are placed in position, sloping outwards from main wall at a spacing of 30–50 cm centre-to-centre,…

This type of roof is widely used in the modern construction. Here steel bars and concrete are used to form the roof. This consists of an RCC roof slab resting on walls or beams. For short spans (length to width ratio greater than 1.5) the slab is treated as one-way slab otherwise it is treated…

It is an old type of flat roof used in the old Madras province. This type of roofing is not used now-a-days. It consists of three layers, viz., terrace bricks, brickbat concrete and flat tiles placed in this order in lime mortar over wooden joists (Fig. 25.11). Figure 25.11 Madras terrace roof Teak wood joists are…

Flat roofs are used in the areas which have less rainfall and no-snow fall during the year. Drainage in a flat roof is a major problem unlike a sloping roof which has an excellent drainage facility. A material which could be arranged in a trussed form and which satisfies the general requirements of a roof…