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.

Benifits of Steel Buildings

There are many benefits to building with steel over conventional construction methods. A steel building is probably one of the most economical building choices you can make. Steel buildings have many features not available with many other forms of construction. Steel buildings are typically more economical than conventional methods and can be completed in approximately two-thirds the time required for conventional construction. The appearance of steel buildings can easily be enhanced with many forms of exterior finishes. A suitably insulated metal building can drastically decrease heating and cooling expenses. Insulated roof and wall systems preserve and reassure thermal efficiencies. Extended life materials reduce maintenance, and eliminate troubles such as structural deterioration, rotting and insect damage.

Base Condition

Every metal building has some type of base connection along the building perimeter, allowing the connection of sheeting. This "base condition" determines exactly how the panels connect to the foundation. To prevent water and pests from entering the building at the base, panels extend below the finished floor of the building. Online design and pricing systems allows users to choose from a number of different base options.

Standard Base Angle - Our system defaults to a standard base angle condition. This condition consists of a single angle member, attached to both the wall sheets and the slab. Please note that the standard base condition requires that the slab be formed with a 1½" sheet notch to allow the sheets to extend below the top of the slab.

Deluxe Trim - Deluxe base trim is another option for buildings with concrete slab foundations. Deluxe base trim combines base angle and trim into one piece, providing all the benefits of base trim and base angle. Deluxe base trim is only available in burnished slate color.

Base Girt - The base girt option is designed for buildings that sit on piers rather than a full slab. A base girt system does not rest on or attach to the foundation. The base girt attaches to clips on the columns about 6" above the foundation. The base girt provides a great connection for liner panel.

Base Channel - The Base channel is a "cee" shaped section that runs the perimeter of the building connected to the floor. It is most commonly used when a liner panel, or interior wall, is going to be installed. The "cee" section provides a pre-positioned connection point for inside panels. This approach requires a sheet notch in the slab (for an alternative, see the combination of base channel and base trim below).

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.

Installation and Selection of Insulation

We provide the highest quality products available. However, proper installation and selection is imperative for maximum effectiveness. Please refer to installation instructions to ensure correct procedures are used. Facings that have been torn or punctured are no longer capable of blocking water vapor and may eventually do more harm than good. Be sure to quickly patch any holes in the vapor barrier.

When selecting a facing, special consideration should be given to its reflective quality. A facing with high reflectivity reduces the need for high light levels in work areas. This results in reduced energy costs and increased productivity.

Although the fiberglass insulation itself is not affected by cold weather, the facing is. Colder temperatures can cause cold crack, a situation where the facing becomes brittle and if handled can crack. Bay Insulation recommends that vinyl faced fiberglass products never be installed in temperatures below 40 degrees.