What is the difference between coffered slab and waffle slab?

What is the difference between coffered slab and waffle slab?

Coffered slab (Fig. 1) is a kind of ribbed slab, it is also called waffle reinforced concrete floor. Coffered slab is a ribbed structure with reinforced ribs in the lower zone which have mutually perpendicular arrangement. ... The resulting thickness of the slab is much less flat.

What is the advantage of ribbed slab?

Ribbed and waffle slabs provide a lighter and stiffer slab than an equivalent flat slab, reducing the extent of foundations. They provide a very good form of construction where slab vibration is an issue, such as laboratories and hospitals.

What is the difference between solid slab and ribbed slab?

Ribbed slabs are slabs cast integrally with a series of closely spaced joists which in turn are supported by a set of beams. The main advantage of ribbed floors is the reduction in weight achieved by removing part of concrete below the neutral axis. ... Solid slabs of uniform thickness can be one-way or two way.

What do floor joists sit on?

At the foundation level, floor joists rest directly on a sill that is treated with preservative so that contact with the foundation will not promote termites or rot. Their exact construction and connection with the wall studs depend on the method of framing that is utilized.

What is the minimum end bearing for a floor joist?


What is not allowed when cutting holes in joists?

Cuts, notches and holes bored in trusses, laminated veneer lumber, gluelaminated members or I-joists are not permitted unless the effects of such penetrations are specifically considered in the design of the member. IRC R602.

How much does a beam need to sit on a post?

Engineered lumber beams must have end bearing as per the manuf. specs. The larger beams typically require 3 to 3 1/2 inches. Larger beams typically have longer spans or other beams (point load) on them.

What does span mean when talking about a floor joist?

Joist span refers to the measurement covered by the joist between supporting structures, such as beams or foundation walls. Builders generally use pre-calculated tables to tell them appropriate joist spans for each lumber species, size, and spacing.