Building Technology 5

STEEL DECKING

` Origin of Steel Decking

` Definition of Terms

` Types of Steel Decking

` Advantage & Disadvantage

` Examples of buildings

STEEL DECKING Steel decking is used in a wide

variety of commercial and industrial applications.It includes steel roof and floor decking, aluminum floor decking, and acoustical metal decking.

Metal decking typically has a ribbed or corrugated profile that is achieved through a process called roll forming. Large sheets of metal are pulled off of rolls and led through rolling dies that create the ribbed profile.

Steel decking, when used as flooring, can provide additional stability to a structural frame. When used as roof decking, a narrower rib pattern must be created to increase strength and support roofing materials. Steel decking is an economical, permanent, easy-to-install option for builders. As a cold-rolled steel product, it offers high quality with little maintenance. Steel decking exposed to the elements will typically be galvanized to prevent rusting.

The bent profile of the

typical steel deck works

the same with that of the

folded plates, serving

as a homogenous “little

beams combined with

the flat slab,” in steel.

Steel decking was first used to support a

concrete floor in the 1920s. Loucks and Giller

described a steel-deck system in a patent filed in

1926. In this early development, the steel deck

provided all the structural resistance, concrete was

added to provide a level walking surface and fire

resistance. The use of steel deck was attractive to

constructors as it served as permanent formwork and

construction platform, and was an attractive

alternative to reinforced concrete slab floors.

ORIGINS OF STEEL

DECKING

By 1938, engineers were using a non-

composite cellular floor system produced by the H.H.

Robertson Company (referred to as the keystone

beam because of the dovetail shape of the steel deck

cross section) in industrial buildings.

ORIGINS OF STEEL

DECKING

The first composite slabs, concrete reinforced

by the steel deck, appeared in the 1950s. The first

was a product known as Cofar, produced by the

Granco Steel Products Company, which was a

trapezoidal deck section with cold drawn wires (T-

wires) welded transversely across the deck ribs. The

slab was analyzed as a traditional reinforced

concrete slab and found to be in good

correspondence between predicted and experimental

strengths.

ORIGINS OF STEEL

DECKING

In 1961, the Inland-Ryerson Company

produced a trapezoidal steel deck with indentations

rolled into the profile to achieve horizontal shear

transfer between the concrete and steel. This floor

deck, known as HiBond, was the forerunner of most

modern composite steel decks that use

embossments to develop bond between the concrete

and the deck.

ORIGINS OF STEEL

DECKING

By the mid 1960s, a number of manufacturers

were producing composite steel decks, validating the

load carrying capacity of the composite slab through

proprietary testing. Each steel deck manufacturer,

employing sound engineering design principles,

developed their product by extensive independent

research so that the approving building code agency

would grant acceptance of the particular steel deck

system. In many cases the local building code official

requested additional test data from the manufacturer,

depending on the particular construction situation.

ORIGINS OF STEEL

DECKING

Plank

The plank is an important part of steel decking. This is the

portion upon which you walk. The metal plank can be a grate or have a

special tread for traction. Planks may also be solid panels that can be

designed to fit the space you need. Planks come in several materials

and types including steel, fiber glass, expanded metal or bars.

Stair treads

Like planks, the stair treads can be grating, made of

expanded metal, slotted, or have large or small holes. Stair treads can

also come with traction, or raised holes on the tread itself.

Terminologies

Composite steel (SEE PICTURE ON THE NEXT SLIDES)

Composite steel decking is cold-formed, acting as permanent

decking. This type of decking comes in a variety of finishes including

phosphatized, galvanized or painted. Composite decking works well

with concrete and is offered in various gauges, ranging from 16 to 22.

Roof decking (SEE PICTURE ON THE NEXT SLIDES)

Roof decking is a type of steel decking made in various

gauges and finishes that make them weather resistant. Various

configurations of roof decking include rounded or angular corrugations.

Button punch

A button punch tool helps in the construction of the steel

decking. The tool crimps the various steel decking pieces together so

that they are welded securely.

Terminologies

Metal Roof Deck

Steel roof deck is designed for pitched, flat, or arched

construction on virtually all types of buildings. Roof deck is popular

because it is strong, lightweight, economical, and easy to install. Roof

deck can be produced with acoustical, cellular, or cellular/acoustical

properties if required.

Composite Metal Deck

Composite Steel Floor Deck has a ribbed profile with

embossments designed to interlock with concrete slabs, creating a

reinforced concrete slab that serves the dual purpose of permanent

form and positive reinforcement.

Types of Steel Decking

Metal Form Deck

Steel Form Deck is designed to serve as a permanant steel

base for poured reinforced concrete floor slabs. Installation is fast,

easy, and economical: the need for temporary wood forming is

eliminated.

Types of Steel Decking

TYPES OF STEEL DECKING (BASED ON PRODUCTS/APPLICATION)

Roof Deck Roof deck are typically used as the structural component of many flat, pitched, or arched roof systems because of their benefits with regards to strength, weight, and economy. It is commonly attached to open web steel joists, structural steel, or light gage framing. Aside from the standard roof deck profiles, long-span, cellular, acoustic, and cellular acoustic products are also available to meet project needs.

COMPOSITE FLOOR DECK

Composite Steel Floor Deck

has a ribbed profile with

embossments designed to interlock with concrete slabs, creating a reinforced concrete slab that serves the dual purpose of permanent form and positive reinforcement.

Non-Composite (Form) Deck Non-Composite decks are used when only a form for a concrete slab is desired.

Long-Span (Deep) Deck A variety of long-span decks are available for both roof and form applications. The profile depths of 4 ½”, 6”, and 7 ½” allow the deck to span longer distances between supports and achieve additional load capacity.

Cellular Deck Cellular deck consists of a flat liner panel shop welded to a deck element to create a deck product that provides the strength of a corrugated deck while achieving a flat appearance from the underside. The cellular deck can be used for a roof, composite, or form deck application.

Acoustic Deck Acoustic deck contains fiberglass insulation batts that are designed to absorb sound and prevent echoing within the space. For non-cellular deck there are perforations in the webs with fiberglass batts field installed on top of the deck in the low flutes. Cellular deck has perforations in the liner panel with the batts shop installed into the cells of the deck.

Bridge Form Our bridge form product line consists of a variety of profiles that are typically used to form the slabs of bridges or thick slab applications. Specialty bridge accessories as well as crimped ends for some of our profiles are also available.

STEEL DECKING

Picture of steel decking for

flooring:

View of steel decking for flooring (seen

from its underside):

Close-up View of steel decking for

flooring (note the temp bars, placed

bothways (B.W.):

Image of steel decking for

flooring (applying shotcrete)

Detailed drawings:

Composite beams incorporating composite slabs. (a) Deck

perpendicular to secondary beam. (b) Deck parallel to

primary beam

Advantages:

1. Speed of construction

2. Safe method of construction

3. Saving in weight

4. Saving in transport

5. Structural stability

6. Shallower construction

7. Sustainability

8. Easy installation of services