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.

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

Ridge Vent

Ridge vents come completely assembled for ease of installation. Ridge vents supplied by Metal Building Depot are of a low profile design to provide gravity type ventilation. Because gravity ridge vents are designed to allow free airflow, some penetration of water during blowing rains is to be expected. Standard available finishes for the ridge vents are polar white and galvalume. Other colors may be available at an additional cost. Nominal ridge vent length is 10'-0". Ridge vents are available with 9" and 12" throats. Bird screens are provided as a standard. The ridge vents can be ordered as continuous or single units. Exterior parts are 26 gage painted or galvalume. Interior parts are all made of G90 galvanized steel. The substructure consists of 10 gage saddle straps with interior baffles of 24 gage steel. Lifter arms and damper slides are made of 18 gage steel. Manual operation is through activation of a pull bar which is attached internally to bell cranked type lifter arms connected to the damper with Teflon coated pins through the damper slides. Dampers are spring loaded to remain in the open position until the pull bar is operated and locked in the closed position. Dampers operate in a vertical manner. Each vent is opened by a pull chain that extends approximately 12" below the roof unless noted otherwise on the order documents. Other opening mechanisms are available at an additional cost upon special request. Ridge vents should not be placed closer than 5’-0" to the endwall steel line to allow room to properly flash the building. For example, a 90’-0" long building with ridge vents required the entire length should have no more than (8) units. The ridge vents are available with the following accessories:

Steel Buildings Are Economical

A steel building is an economical choice and will save you money in construction costs. We make it easy for you to design the building that's just right for you. We have implemented years of steel building design and engineering experience into our system, and you can be confident in your design requirements without worries. The "design it yourself" concept was designed to reduce costs. When you design your own steel building, we use the information you submit online to detail your steel building, just as you designed it. You can design endless steel building combinations without anyone trying to sell you a thing or make a commission. Take all the time you need, making changes to your building configurations are a snap. And of course, we are here to help you, when and if you need it. You can speak to a customer service representative, designer, engineer or project administrator at your convenience. We have no commissioned sales personnel, just experienced steel building professionals waiting to serve you.