Secondary Framing

Secondary framing is created from rolled steel coated with a red-oxide primer finish in gages from 12 to 16 to provide an extremely rigid, and corrosion resistant structure. The following elements are formed as secondary framing:

Girts (walls) & Purlins (roof): These members run the length of the building providing rigidity, and a sturdy skeleton to attach the sheeting. They are rolled from steel coils 12,14 or 16-gauge steel, or thicker if needed. All girts and purlins are pre-punched for ease of assembly.

Eave Struts: This is a rolled member formed into a "C" to match the pitch of the roof. The eave strut is also made of 12, 14, or 16-gauge steel.

Temperature Control

Your geographic area will, to a great extent, influence the type of insulation that will provide the best performance. If you live in a mild climate and your building is used for farm equipment storage, insulation may not be necessary. If you are planning to have employees working in a building, you should probably install insulation, particularly in areas where temperatures are extreme. Energy savings will quickly pay for insulation if the building will be climate controlled.

Proper Ventilation of a Building

Proper ventilation in a building can be an effective measure for condensation control. The end use of the building must be the controlling ventilation design parameter, especially above drop ceiling areas. Ventilation system design should be done at the initial building design stage. Use of a design professional is strongly recommended to assure the best possible system.

CONDENSATION CAN BE MINIMIZED THROUGH CONSIDERATION OF CLIMATE, RELATIVE HUMIDITY AND THICKNESS OF INSULATION.

Controlling Condensation

Two things must be present for condensation to occur: warm moist air and cool surface temperatures below the dew point. The proper control of these two factors can minimize condensation.

In metal buildings, we are concerned with two different areas or locations: visible condensation which occurs on exposed surfaces below dew point temperatures, and concealed condensation which occurs when moisture has passed through the vapor retarder and into interior roof and/or wall cavities and then condenses on a surface below dew point temperature.

Heat Transfer

Effectively controlling temperature in a steel building requires insulation to be present along exterior walls and roof. When a temperature differential is present in an enclosed steel building, heat will work from warmer areas to colder areas until the temperature in the building has stabilized. At the point of thermal stabilization, the cooler (and heavier) air will be present at lower elevations and warmer air will be present at the roofline. The function of insulation is to help stabilize air temperature at more desirable levels. When it is hot outside, preventing heat from transferring into the building is the goal, and of course in the winter we want heat to remain inside.

Heat transfer occurs in three ways:

Conduction : Occurs in a solid or liquid when heat from one object is transferred by touch to another object. An example of this occurs when a pot on a stove will heat up by conductive heat transfer from an electric coil.

Convection : Occurs with the physical movement of air. There are two types of convectional heat movement. The first is natural, where hot air rises displacing the cold air and moving it down. The second type is forced or mechanical convection. This occurs when an object, like a fan, physically moves or "forces" the air to move.

Radiation : Occurs when an object is warmer or hotter than the air around it. For example, the sun, which is hotter than everything around it, radiates heat waves that travel through the air and is either absorbed by or reflected by the surface it comes in contact with.