Reinforced Concrete Roof Thickness

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

Reinforced concrete roof thickness.

With that in mind i ve seen slabs as thick as 16 18 due to column spacing. It is recommended that minimum 90 mil 2 3 mm thick reinforced butyl rubber membranes be used for green roof assemblies. The reinforcement is usually though not necessarily steel reinforcing bars and is usually embedded passively in the concrete before the. Concurrently the roof for a house is not a particularly large or costly element of the total cost of a house.

A concrete roof is exactly what it sounds like. 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. In general a minimum fall of 1 in 80 will help to prevent ponding of water. Would cause a breakdown on the roof surface.

Arch 631 note set 10 1 f2013abn 3 reinforced concrete is a composite material and the average density is considered to be 150 lb ft3. It has the properties that it will creep deformation with long term load and shrink a result of. Such slabs left unconnected to walls caused many deaths in the 2005 quake from school roof collapses. During construction precautions must be taken to prevent excessive moisture from being trapped between the reinforced concrete roof structure and membrane.

Ubc recommends minimum thickness of concrete floor slabs supported directly on the ground to be 89mm whereas bcgbc4010a apply structural principles to residential low rise constructions determined minimum thickness to be 100mm. For example the florida based company hurricane proof systems offers a 7 inch 18 centimeter slab of concrete in three layers. Commercial is typically steel w a composite deck so you ll have a 5 6 slab sitting on top of steel beams. If reinforced concrete were to be reused strong connections would have to be made between roof and walls.

Concrete thickness 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. Exact specifications vary but most concrete roofs are several inches thick. So the recommended criteria for the minimum quality of the concrete to be used in an exposed concrete. Sheets normally are 60 mils 90 mils or 120 mils 1 5 mm 2 3 mm or 3 0 mm thick.

This is one of the common causes of flat roof waterproofing failure. Reinforced concrete slabs are heavier and generate higher seismic forces in an event.