Perm Rating

The perm rating, or permeance, is a measure of the amount of water that passes through one square foot of material per hour. The lower the perm rating, the more effective the barrier. A facing material with a perm rating of 0.1 or less is considered excellent. Anything with a rating above 1.0 is not considered a vapor barrier.

Condensation Control

The condensation process occurs when warmer moist air comes in contact with cold surfaces such as framing members, windows and other thermally conductive accessories, or the colder region within the insulation itself (if moisture has penetrated the vapor retarder). Warm air, having the ability to contain more moisture than cold air, loses that ability when it comes in contact with cooler surfaces or regions. When this happens, excessive moisture in the air is released in the form of condensation. If this moisture collects in the insulation, the insulating value is decreased.

In dealing with condensation, air may be considered to be a mixture of two gases-dry air and water vapor. One thousand cubic feet of air at 75°F can hold up to 1.4 pints of water. At 45°F, it can hold only 0.5 pints.

Relative Humidity is a percentage measurement of the amount of water vapor present in the air in relation to the amount it is capable of holding at that temperature. Therefore, 50% Relative Humidity would mean that the air is carrying only one-half of the total amount of moisture that it could be holding at that particular temperature. Cold outside air is usually much drier than warm inside air. Therefore, you can lower the Relative Humidity by bringing in outside air to mix with and dilute the moist inside air. At 100% Relative Humidity, the air is "saturated."

The temperature at which the air is saturated and can no longer hold additional moisture is called the dew point temperature. Whenever air temperature drops below its dew point, excess moisture will be released in the form of condensation. Condensation problems are most likely to occur in climates where temperatures frequently dip to 35°F or colder over an extended period of time.

Steel Frame Construction

You can feel confident about building with steel. It is not vulnerable to the elements to the same degree that other building materials are. There are a few reasons why steel frame construction stands out more than other building materials. Wood has always been a standby, but its susceptibility to weather and aging make it less than ideal.

Steel frame construction is very sound should there be a detrimental natural occurrence such as an earthquake or severe storm. You steel building should be manufactured to meet all local and applicable codes. Steel frame construction is a serious way to address the risk posed to you and your belongings should a weather emergency arise. Reputable steel building manufacturers only ship pre-engineered steel building systems when standards and codes are met.

It is hard to look past the options and design flexibility that you get with metal and steel buildings. It is not just quality materials that are impressive, but the many accents that can turn a metal building into a beautiful landmark. If you are suffering from lack of space or simply looking for any kind of expansion, check out the range of high quality steel buildings that just might solve your dilemma.

Frame Types

Unlike any of our competitors, we allow you to price all building frame types. Select from Clear-span or Modular rigid-frame buildings. We allow you the full flexibility to choose Gable, Single Sloped or Offset Peak building shape. By far, we offer the widest selection of building and frame types. For options not available through the online system, you will need to request a special quote.

Clear-span Frames - A clear-span rigid frame offers strength and economy. Since no interior supports are necessary, this design is best when you require large areas of clear and uninterrupted space. Factories, warehouses and agricultural buildings are just a few building types that may utilize a clear-span frame building. A clear-span design does have size limitations. As the desired width increases, the frames will become larger and heavier to carry greater loads across the length of the frame. At some point the cost will outweigh the benefit. Even so, clear-span buildings are still effective for buildings as wide as 150' feet and wider in some cases.

Modular Frames - Modular frames use interior columns to evenly distribute the load; reducing the cost of both the frame and foundation of extra wide buildings. The economical advantages become obvious when a building width is about 100' wide or wider. As a result, almost all buildings 100' wide or wider have interior support columns. Modular designs are often used for large factories and warehouses.

Single Slope Frames - Single slope frames have high and low eave heights creating a roof that "slopes" from side to side. To select a single slope design, you specify one eave height and define the roof pitch. Single slope designs are frequently used for strip shopping centers, offices, and RV/Boat storage facilities.

Just about every steel building has at least one framed opening. It is not unusual for buildings to have several openings. Most openings are created for an overhead door, but can be used for the installation of glass fronts or other entries. Most other online sellers offer "field located" framed openings, which require cutting and fabricating on the job site. Metal Building Depot always provides factory-located openings unless your project requires something otherwise.

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.