Horizontal Spanning Systems

The system that is used to classify a building (ie steel frame) is also called a horizontal spanning system. These can be grouped by material and ability to span in one or two directions.

Wood

1. Light wood- composed of a post and beam type construction using relatively small elements

2. Heavy timber- large elements able to span longer than light wood timber

3. Glu-laminated- elements made of layers of wood glued together; creates a larger beam/column that can span further

Steel

1. Solid beams/girders- common for high rise structures; spans further than wood frames

2. Open Web Joist- lighter than solid beams, spanning further, but with greater depth

Concrete (Cast in Place)

1. One-way solid slab- carries loads in one direction, spanning further in one direction over another

2. One-way joist slab- monolithic slab with joists cast in it

3. Two-way flat plate

4. Two-way slab with drop panels/capitals- monolithic slab, but instead of beams spanning between columns, the columns have a capital

5. Two-way waffle slab- a deeper slab with pockets enabling it span further in two directions

Concrete (Precast)

1. Slabs and hollow core planks- planar system, constrained by length given it's cast off-site; slabs are solid, planks take material out of the center to make it lighter

2. Precast T's- Acting more like beams, these span a long length and work well for heavy loads (think parking garages)