ROOFS( FLAT AND SLOIPING)

                             ROOF

    A roof is a covering  on the enclosure made for a building . It is essentially provided to protect the inhabitants from the effect of sun, rain, wind etc. The type of roof depends upon the local climate requirements . For plain regions , where the rain fall is less as  compaired  to hilly or coastal  areas, flat terraced roofs  are used. Light  weight roofs consist of trusses  and sloping roofs  and are  thus  preferred for factories , godowns, big stadiums etc. where large area are required to be roofed. Flat roofs  help in providing  more floor  are for use in way  of multistoreyed buildings.

                 Roofs are broadly  classified into the  following types.

1. Pitched , pent  or sloping roofs.
2. Flat roof.
3. Shell roofs and folded slabs, and. 
4. Domes.              

 SLOPING ROOFS

      The roofs  which are  provided  with considerable  slopes  on one or all the four  sides  are known as sloping  pent or pitched  roofs. These roofs are used for covering large areas.

     TRUSSES:  Sloping roofs  are constructed by spanning the walls with  wooden, steel or composite materials  frames  and then covering them  with roofing materials. These frames are known as trusses.

                          Trusses  are of many types. The  selection of the  type of truss  depends upon the span, nature of roof covering  material and  purpose for which  the building  is to be used. Trusses  may be fabricated out of  timber members  or steel  section, pipes, R.C.C. etc.

Wooden trusses:   These trusses  are economically  and safely  used  upto  a span  of 12 metre . After which  these trusses  become heavier and uneconomical . Steel  trusses are then  preferred.

Lean to roof:    This roof  consists of  common rafters supported  on post-plate  one end and on wall plate  at the other end. The rafters  are kept inclined  to one side only. It is specially  used for verandhas  or sheds upto 2.5m widths. Tiles  sheets  or slates  can be used as roof  covering  materials.