Floor Joists On Concrete Slab

A concrete slab on grade works well on relatively level sites with a first floor or basement level that will be relatively close to existing grade.

Floor joists on concrete slab.

Sizes and spacing for round. Secure each length to the slab with concrete nails spaced approximately 80 cm 32 inches apart and 20 to 30 cm 8 to 12 inches from each end. While some floors are built directly on a concrete slab those built above open areas such as crawl spaces basements and lower floors almost always use a floor joist system to provide weight bearing support for flooring furniture people and everything else in your home. The ribs are usually tapered and are uniformly spaced at distances that do not exceed 750mm.

As the code is written a crawl space foundation must have a minimum of 18 inches although there is an exception that states the use of pressure treated lumber is acceptable if the clearance is less. A one way joist concrete slab is suitable for spans of 6 9m and live loads of 4 6kn m 2. Normal spacing is 16 inches on center from center to center though some floors may have joists on 12 inch or 24 inch centers. Your final cost will depend on the slabs size thickness and if you any special reinforcement such as wire mesh or rebar.

A typical concrete slab costs 4 to 8 per square foot with most homeowners spending between 5 35 to 6 17 per square foot or 113 to 126 per cubic yard for both materials and installation. Floor joists spaced on regular intervals span the areas between supports such as walls foundations girders and beams. The ribs are supported on girders that rest on columns. Install it flat on the slab surface with the outside edge aligned against the side wall or the edge of the floor line.

Square and rectangular dowels and for diamond shaped load plates are provided in aci 302 1r 04 guide for concrete floor and slab construction or aci 360r 06 design of slabs on ground. Since fill will need to be imported into the house footprint to bring the grade up to the underside of the slab floors that will be high off the ground are not logical candidates for a slab on. These will be the end sill plates that support the ends of the floor joists. Install it flat on the slab surface with the outside edge aligned against the side wall or the edge of the floor line.

It consists of a floor slab usually 50 to 100mm thick supported by reinforced concrete ribs or joists.