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.

On The Farm

I don't know of any farm operation that could get buy without barns for equipment storage, feed storage or any other general warehousing needs. Many older farms are now removing old wooden structures and replacing their old buildings with new steel structures. While the old antique tractor may look good in front of the old barn, many are weary of storing precious items in an old rotten structure. Steel is stronger, straighter and will last eons longer than wood. In a home, wood is fine. Houses are designed so that the wooden structural components do not have direct exposure to the elements, but on the farm it is often hard to prevent the outside from coming into the barn.

Visible Condensation

To effectively control visible condensation, it is necessary to reduce the cold surface areas where condensation may occur. It is also important to minimize the air moisture content within a building through the use of properly designed ventilating systems.

Walk Doors

Walk doors can be provided as pre-assembled or knock down (field assembled). Metal Building Depot provides solid doors for both options in the following sizes: 3070, 4070, and 6070. The walk doors are typically keyed alike per project. Because of unknown variables, Metal Building Depot does not offer fire rated doors or doors to fit in masonry.

Features of the pre-assembled doors are as follows:

Foam insulated specifically designed for metal building use. Pre-assembled and self-framing for ease of installation. No framed opening required if Metal Building Depot standard girt spacing is utilized. Doors are finished in a two-coat primer; color selection is white or bronze. Doors are shipped in wood crates for protection. All doors have Grade 2 lever locks as standard. Hinges are ball bearing and powder coated. Insulated jambs. 3070 and 6070 doors are made of 20-gage material, 18 gage is available.

Features of the knock down doors are as follows:

Foam insulated specifically designed for metal building use. The walk door is shipped knocked down for field assembly. Doors are textured 20 gage galvanized prime painted and pre-finished in either white or bronze. Weather stripping and standard entrance lock is included. The walk door package is shipped with polybag and full cardboard carton. All doors have Grade 2 lever locks as standard. Hinges are ball bearing and powder coated.

Facings

In addition to acting as a decorative protection barrier, facings serve an integral part of the overall insulation system. Facings provide vapor barriers, light reflectivity and structural strength. In some cases, a reinforcement of fiberglass scrim is used for extra rigidity and greater impact resistance.

The effectiveness of a vapor barrier depends on three primary factors:

1) Location within the insulated section

2) Permeance

3) Proper installation