Curved Roof

These are the modifications of pitched roofs and are frequently employed in modern age to cover large areas shed/roofs and domes are the varieties of curved roof. Curved roofs are mostly used in big structures such as monumental works, factories etc. They can be constructed of materials such as timber, R.C.C etc.

There are 2 common forms of shell roof

• A north light shell roof
• A barrel vault shell roof are as shown in fig below.

A dome is generally a round vault which is forming a roof. It is commonly used when roof is to be provided on circular regular polygon shaped walls or brick works. These roofs afford pleasing appearance and due to arch action, the stresses are considerably reduced which results in thin sections for curved roofs.

Construction Procedure & Details of Curved Roof

• Pre-cast units of cement concrete tiles of size 70 x 70 cm with a uniform minimum thickness of 20 mm in the form of domes with a rise of about 50 mm are used.
• Pre-cast units of R.C.C. 1 : 2 : 4 beams are prepared as per design usually 90 mm deep and 130 mm wide as per design usually 90 mm deep and 130 mm wide.
• The beams are suitably laid on the supporting walls.
• After spreading some mortar on the edges of beams the tiles are then placed in proper position. The minimum bearing of tiles on beams should be 25 mm and that on walls should be 50 mm to 70 mm.
• The haunches between the humps of tiles are filled up with cement concrete of proportion 1:2:4.
• Suitable water-proofing treatment to the roof is given at the top. The roof thus exhibits a flat surface at the top and curved surface at bottom.

Advantages of Curved Roof

• It can be constructed in short time.
• It does not require skilled supervision.
• Cheap in construction.
• Requires less frame work.
• Curved roof mainly reduced the emission of harmful CO2 gases.
• The construction of these roof is simple in technique and it is and much similar to standard flat roof and moreover it is wind resistant. These qualities make it low maintenance roof.
• The curved roof is generally designed by architect, hence they are well planned according to the location of construction.

Disadvantages of Curved Roof

• As the complexity of the design of curved roof increases, the cost of the roof also increases.
• Height, Curve and Materials used for covering the roof are generally considered while estimating.