1. Field of the Invention
This invention relates to a rollformed sheet metal structural shape fabricated from a single sheet of metal for use in building construction. The structural shape is particularly useful as a stud or mullion in wall construction or as a purlin or sub-purlin in deck construction. This invention also includes an interior deck or roof deck construction using the sheet metal structural shape of this invention.
2. Description of the Prior Art
Building interior and roof decks are generally constructed by securing a series of spaced structural shapes to the structural beams of the building with formboard or other suitable material placed between the structural shapes and covered with insulation or concrete. For weather-proof roof decks, a weather-proof roofing surface is secured to the top of the structural system. The shapes must be safe for workmen to walk on during construction, must resist both upward and downward environmental forces after the deck is assembled, and must not corrode during use. The shapes must be relatively inexpensive to manufacture, and easy to install, as well.
U.S. Pat. No. 1,360,720 describes a light weight metal bar structure useful as a spar in wings, fuselages, struts and the like in the construction of airplanes. The bar structures are symmetrical about both a vertical and a horizontal bisecting axis, and include an expanded shape on both ends of a center web which may bend if the structure is walked upon. The expanded shapes have equal length flanges at both the top and the bottom of the bar structure, which would make the structure difficult to install on a building beam from the top of the beam, and would make it very difficult for formboard and the like to be placed between the lower flanges of adjacent bar structures and have adequate support. The structure is also somewhat difficult to manufacture, as it is made of several pieces of sheet metal. West German Pat. No. 821,703 discloses several structural shapes which include a dominant center web portion, which also tends to "trip" or collapse if walked upon.
Thus, there is a need for one-piece structural shapes which do not bend over or collapse when walked upon during construction, are resistant to both upward and downward pressure created by the wind and other environmental forces, may be installed on building beams from the top of the beams, may be easily fitted with rigid formboard and the like on the lower flanges between adjacent structures, and do not corrode during use.
Accordingly, an object of this invention is to provide sheet metal structural shapes for use in building construction.
Another object of this invention is to provide sheet metal structural shapes which are especially useful as studs or mullions in building wall construction.
It is a further object of this invention to provide structural shapes which do not collapse or bend over when walked upon during building construction.
Yet another object of this invention is to provide structural shapes which do not corrode during use.
Still another object of this invention is to provide structural shapes which resist upward and downward forces and provide improved composite strength in a poured concrete deck.
A still further object is to provide structural shapes which may be installed on building beams from the top of the beams, and may be readily fitted with formboard between the bottom flanges of adjacent structures.
Yet another object is to provide structural shapes which may be rollformed from a single sheet of metal.