There are many different types of frames that are used in metal building construction. A basic understanding of the different types of frames will help you make the best choice for your application. The most popular steel building frame type is the clear-span rigid frame, which offers substantial strength and durability. The other styles: modular, single slope, Gambrel, asymmetrical, classic and lean to, each offers unique advantages.
Mainframes, vertical columns, and rafters are constructed from ¼” plate steel (ASTM# A.1011 50ksi) to form “H" or "l" beams with base and connection plates pre-welded and punched for ease of assembly. Clips used to secure purlins and girts are pre-welded to the frame. Welded clips are more structurally sound and result in saving a significant amount of time when erecting. Each individual component is pre-cut, pre-drilled, numbered and stamped for easy identification during assembly.
Clear Span Gable Symmetrical FrameClear-span frames require no interior support beams, which allows for an unobstructed interior which is suitable for almost any application including retail space, office space, production facilities, and airplane hangars. The clear-span frame here is gable symmetrical - meaning that it is double-sloped with the ridge in the center of the building.
Modular Gable Symmetrical Frame
Modular frames make use of interior load-bearing columns to more evenly distribute the load of the entire building. A modular frame works very well for projects that require extremely large steel buildings. The addition of an interior, or intermediate column on wider buildings, especially those with high snow loads helps reduce the size of the rafter and column, making the project more economical. The modular frame here is gable symmetrical - meaning that it is double-sloped with the ridge in the center of the building.
Structures using the modular frame type with interior columns evenly distribute the weight of the building. This frame allows for wider buildings to be constructed while keeping building costs down. Some of the most common uses for modular steel frame buildings include:
Factories: Different industries require varying sized factories. With modular framing, you can design and build steel frame buildings large enough to accommodate your unique factory specifications.
Warehouses: Since storerooms and warehouses tend to be larger than regular steel framed buildings, the use of modular framing works as an ideal solution. Modular framing also allows you to construct custom steel framed buildings that are large enough to meet your specific needs while doing so at an affordable price.
Clear Span Single Slope Frame
Single slope frames allow for a pitched roof, a frame that is higher on one side than it is the other. Pitched or single sloped roofs may be a necessity in areas that get heavy rainfall or snowfall, because they allow the roof to shed excess rain or snow to one side. Additionally, a single slope is ideal for retail buildings where a mansard or parapet is desired for a more aesthetically pleasing entry.
The measurement for a single slope frame structure is done by specifying the eave height of the lower side and afterwards defining the pitch or slope of the roof. A roof pitch basically refers to the number of inches a roof rises vertically for every 12 inches it runs horizontally. The most standard pitch size for single slope frame steel buildings is ½:12 pitch but it can be steeper also depending upon the building structure. Single slope frame structures find their way into strip shopping centers, offices, retail establishments, office suite areas and mini storage complexes. They are also used for many agricultural applications.
Gambrel FrameBesides being a traditional architectural style, Gambrel Frame offers aesthetic and practical advantages. Roofs that spring from the first-floor wall plate, the way gambrels and capes do, rather than from the second floor. Such roofs are more interesting and visually pleasing. But the gambrel has some advantages over the cape: in particular, gambrel allows more useful space within the framed volume.
Asymmetrical Offset Peak Clear Span FrameA frame who’s ridge is not equal on both sides or whose eave heights are not the same.
The Lean-to frame attaches to and is supported by the main building frame. Leanto frames will either follow the existing building roof slope or fall below it by a minimum of 1’ in order to allow room for connections and flashing.
Primarily used for expansion or extension of a building, lean-to frames can provide additional space very economically. They are commonly used to provide additional office or storage space for a larger building. A lean-to frame typically has a single slope profile (no ridge) and straight sidewall columns. It must be supported by the attachment to another frame.