Category: Roofs and Roof Coverings

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…

A roof covering is a material which is placed over a sloping roof to give protective surface. The primary function of the covering is to prevent the direct entry of heat, rain and snow into the building. Choice of roofing material depends on the type of roof structure, local conditions, cost, the type of building,…

Shape and positioning of members in a steel roof truss are designed in such a way that the members are subjected to either compression or tension. Trusses do not have any bending stress in them. The compression members of the truss are based on the span, slope, the covering material, and centre to centre of…

Different types of timber sloping roofs are discussed below. 1. Lean to Roof This is a roof which is usually used to cover verandah. This is used for spans up to 2.5 m. The roof covering is fixed to battens running across the rafters. It is usually constructed as a mono-pitched roof (Fig. 25.2). Figure…

Following are the terminologies which are relevant to sloping roofs (Fig. 25.1). Figure 25.1 Parts of a sloping roof 1. Span Clear span is the horizontal distance between the walls or the supports. Effective span is the horizontal distance between the centres of bearings of the supports. 2. Pitch Pitch is the slope of a roof…

Sloping roofs are comparatively light in weight and can be used in large to very large spans. They are quite suitable in areas where there are heavy rain and snow. Shapes of sloping roofs are dependent on the area to be covered, material used, light, ventilation needed, etc.