Reinforced Concrete Roof Slab Thickness

With that in mind i ve seen slabs as thick as 16 18 due to column spacing.

Reinforced concrete roof slab thickness.

Exact specifications vary but most concrete roofs are several inches thick. For example the florida based company hurricane proof systems offers a 7 inch 18 centimeter slab of concrete in three layers. A concrete roof is exactly what it sounds like. Typical insulating roof deck form planks manufactured in north america and designed for cast in place reinforced concrete roof decks.

Minimum reinforcement is 0 12 for hysd bars and 0 15 for mild steel bars. Such slabs left unconnected to walls caused many deaths in the 2005 quake from school roof collapses. The maximum diameter of bar used in slab should not exceed 1 8 of the total thickness of slab. Maximum spacing of main bar is restricted to 3 times effective depth or 300 mm whichever is less.

Thickness of the slab is decided based on span to depth ratio specified in is456 2000. 6 mm 8 mm 10 mm 12mm and 16mm. Qaisar ali http www eec edu pk page 5 of 24. Reinforced concrete slabs are heavier and generate higher seismic forces in an event.

For flatwork such as slabs on grade and driveways a minimum thickness of four inches is required but increasing the thickness to five inches can add nearly 50 percent to the load bearing capacity. Thickening the structure along the perimeter by another will serve as an integral footing adding strength where the loads are heaviest. Concrete slab design procedure steps to be followed in the design of slab assuming suitable bearings not less than 10cm find the span of the slab between the centers of bearings. Lb la 16 12 1 33 2 two way slab minimum depth of two way slab is given by formula hmin perimeter 180 2 16 12 12 180 3 73 in assume h 5.

If reinforced concrete were to be reused strong connections would have to be made between roof and walls. For example we build residential in flat plate concrete which will typically have a column spacing of 20 oc and a slab thickness of 8 typ. Department of civil engineering n w f p uet peshawar design of reinforced concrete components of a house. Cross section of a typical cast in place reinforced concrete roof deck formed with one of the typical icf planks shown in figure above.

A solid slab of concrete capping the top of your house.