A Study of Affordable Roofing System using Square Pyramidical Panels

Abstract

Affordability of housing unit is a worldwide concern. The term affordable roofing is used to describe the low cost dwelling units, which are inexpensive and reasonably priced and can easily serve to certain group of people within specified income range. Structural roofing system contributes substantially to cost of construction of housing unit in normal situation; hence, any savings attained in roofing system will reduce the cost of construction of housing unit. In a search of new roofing system, the present study is carried outto check whether the prefabricated roofing would replace the normal roofing process. In the study undertaken, pre-cast RCC roof infill elements are supported on precast RCC joist system. The square pyramidical panels have size of 0.5 m ´ 0.5 m and 0.75 m ´ 0.75 m considered with a rise of 60 mm, 75 mm and 90 mm at the centre. The analysis of the roof system is made by using STAADPRO software and further validated with the software Etabs. The panels are designed using M20 grade concrete and steel corresponding to 415 N/mm². The cost analysis made for the roofing system proposed indicates a cost reduction 19.2% and 39.12% for slab size of 2 m ´ 2.5 m and 3 m ´ 3.75 m respectively, when compared to the conventional slab of same size. The weight of the joist systems and the infill panels are found to be relatively less and can handled easily by two to four masons thus reducing the labour cost. The joist systems and panels are prefabricated and can be easily placed thus eliminating need of shuttering and in situ construction, leading to faster construction of slab. The proposed roofing system is cost effective with a greater speed of construction compared to conventional roofing system.

Keywords: Affordable roofing, precast concrete, cost economics of roofing system, square pyramidical panel