Calculated Thermal Values

Basically it is the reciprocal of the calculated U-Value. By definition it is the summation of all the R-Values for each of the building's components. This method of calculation does not consider the thermal short circuit effect of structural members, fastener population or the compression of the insulation at its structural members. It should also be noted that this type of calculation often indicates heat loss values for building envelopes that are lower than those actually found in the finished structure.

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.

Erectors

Do I need a professional erector to put up my metal building? - A majority of our clients choose to erect the metal buildings themselves. Your package includes detailed erection drawings and an erection manual with every metal building shipped. We design every metal building to be erected easily. If you do not feel comfortable erecting your own metal building, a local contractor can do the job for you at a relatively low cost.

What if I have questions during the erection of my metal building? - We're here to help. We have professional metal building erectors on-staff and they will always be available for your questions.

Do you recommend erectors? - No. Recommending metal building erectors is difficult because we cannot guarantee the quality of their work as we do our own. Check around and you should be able to find a qualified metal building erector in your local area.

How long does it take to erect a metal building? - The time it takes to erect your metal building will depend on the size of the metal building, the size of your crew, and the skill of the workers in your crew. It can take as little as a few days.

Thermal Conductance (C-Value)

A measure of the amount of heat that passes through materials of any thickness.

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.