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.

When you decide to buy a Building

Confirm the accuracy of your building codes. It is imperative that your building conforms to the state, local and federal design requirements.

The items described on your contract are what you are buying. Please be sure to carefully review all contract documents before you sign off. If a contract does not describe an item in specific terms, you should not expect the item to be the best product available. And just as important - is what a contract does not say. Specifically if your contract does not indicate that you are getting framed openings and garage doors - then you are NOT going to get framed openings and garage doors.

Do not sign a contract or agree to purchase a building before you have confirmed that your building will satisfy the requirements of your local building official and YOURSELF. Do not allow a salesman to pressure you into a "panic buy." A "panic buy" is when a customer is pressured into making a purchase to "lock-in" a "so-called" special price. Brokers are notorious for telling customers they could lose an opportunity to get the "deal of a lifetime" if they don't commit to the order right away. Beware of people who urge you to sign a contract before you have made your mind up on exactly what you want.

Understand that making changes after the sale will cost you money. Once the design is completed it will cost money to make changes. If an order is in fabrication - and requires modifications due to customer demands - the entire process has to be stopped, pulled off-line and inventoried. Once the inventory of completed items is confirmed, it's back to the drawing board. You will be responsible for extra time required to re-design the project and all other associated expenses.

Install your building components as specified by the drawings. Seldom do manufacturers use the same design practices and therefore your erection drawings and installation documents are the correct description of the building. Please read and follow the drawing descriptions carefully. An erection manual offers important general guidelines and the proper procedures for erecting a steel building safely. You, your erector and all jobsite crew need to understand and utilize OSHA and all other safety guidelines.

Overall Heat Transmission Coefficient (U-Value)

A unit used to express heat passage through a complete building section, including air films. U-Values serve as a basis for determining transmitted heat loss. The lower the U-Value, the higher the insulation value.

Recommended Installation Methods of Insulation

Roof insulation rolls are cut to lengths that will cover the distance from eave to eave, leaving a one-foot overhang on each side of the building.

1) Start at the end of the building and temporarily secure one end of the roll by attaching the insulation to the eave strut with double-faced tape.

2) Pull the insulation across the purlins with the vapor barrier toward the building interior. Double-faced tape attached to the opposite end of the insulation will keep tension on the roof roll while the metal panels are being attached over the insulation.

3) Install the next roll in the same manner, making sure the rolls are stretched tight, aligned properly and closely butted.

4) Fasten tabs using one of the methods described on the following page. Any rips or tears must be covered with matching facing tape to ensure a tight vapor seal.

5) Trim excess insulation flush to prevent it from acting as a wick and moving water into the building.

Secondary Framing

Secondary framing is created from rolled steel coated with a red-oxide primer finish in gages from 12 to 16 to provide an extremely rigid, and corrosion resistant structure. The following elements are formed as secondary framing:

Girts (walls) & Purlins (roof): These members run the length of the building providing rigidity, and a sturdy skeleton to attach the sheeting. They are rolled from steel coils 12,14 or 16-gauge steel, or thicker if needed. All girts and purlins are pre-punched for ease of assembly.

Eave Struts: This is a rolled member formed into a "C" to match the pitch of the roof. The eave strut is also made of 12, 14, or 16-gauge steel.