Residential Roof Slab Thickness

In general 6 inch 150mm slab thickness is considered for residential and commercial buildings with reinforcement details as per design.

Residential roof slab thickness.

Slab thickness tolerances has long been a point of contention between contractors and specifiers. Loads will vary with the. Slab on ground 1 4 minimum thickness of diaphragms. A solid slab of concrete capping the top of your house.

1 3 minimum thickness of slab on the ground 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. Commercial is typically steel w a composite deck so you ll have a 5 6 slab sitting on top of steel beams. A concrete roof is exactly what it sounds like. Standard concrete floor slab thickness in residential construction is 4 inches.

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. Exact specifications vary but most concrete roofs are several inches thick. Constructing the concrete roof deck. Methods used for finding slab thickness varies for different types of slabs.

To prepare the base cut the ground level to the proper depth to allow for the slab thickness. Constructing a concrete slab for a structural roof is different from that for building a slab on the ground in that attention must concern two important objectives. Five to six inches is recommended if the concrete will receive occasional heavy loads such as motor homes or garbage trucks. Typically a project specification will reference aci 301 specifications for structural concrete which in turn references aci 117 specifications for tolerances for concrete construction and materials.

With that in mind i ve seen slabs as thick as 16 18 due to column spacing. When installed however the shingles overlap doubling the thickness. Minimum thickness most roofs will be sheathed in plywood at least 3 8 inch thick. Standard asphalt shingles add very little thickness to the roof because a standard three tab shingle is about 3 16 inch thick.

One concern is that the concrete must develop the compressive strength intended by the structural engineer in the design of the roof deck. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads.