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What Makes Up a Roofing System

A metal roof is far more than simple sheets of steel. In fact, it is a complete system of materials that work together to provide stability, durability, ventilation, and protection from moisture, pests and weather. Metal roofing components include:

Metal Coils/Sheets: Metal coils are long, continuous metal rolls that have been treated or coated with paint. These are rolled out, cut, and rollformed into a panel for installation. 

Panels: Panels are the rollformed pieces of metal coil that have been shaped into the desired profile/ribbing structure and are ready to be seamed together to form a roof.

Seam: The side rib at which two metal panels come together and are connected. Seams are formed using a rollformer and are then snapped together or mechanically seamed together.

Profile: The shape metal panels are formed into. The profiles are what determine how the panels fit and connect together.

BF Underlayment: Underlayment is the layer of material that goes underneath the metal panels and provides protection from water and moisture, ice, high temperature and vapors. Underlayment is generally installed mechanically or self-adhered with a glue backing on the roof deck. While there are many different types of underlayment, common materials are synthetic (polypropylene or polyethylene) felt and fully-adhered peel and stick. 

Clips: Clips are used to attach the metal roof panels to the roof deck. Clips are put on the standing seam portion of the bottom panel, which is then attached to the roof deck by fasteners. After the clip is put on the bottom panel, the top panel is placed over the clip and the two panels are snapped together or mechanically seamed into place, which securely attaches it to the structure. 

Fasteners: Fasteners are the screws used to attach the metal roof to the roof deck during installation.

Rivets: Rivets are similar to fasteners but require a special rivet gun to install.

Ventilation: Ventilation provides cool and dry air flow, which is vital to meet building codes, reduce utility costs and minimize long-term building damage caused by improper ventilation (such as moisture forming on the underside of the roof). Ventilation can be polyester (which prevents moisture absorption and holds together to keep out pests) or other inferior products such as polyurethane (which expands as they soak up water and contract as they dry out. This constant flux causes them to crack and lose their ability to perform effectively. 

Closure: Roof closure strips are sections made of foam or other flexible material that are used to seal the spaces left along the edges of a roof by corrugated metal roofing. These strips seal out animals, birds and insects. They will also stop wind, rain and other weather-related problems.

SealantSealants are used during installation to seal out water, dirt, wind and other substances that can get into small spaces, making the roof as weather-tight as possible. Sealants, which are typically made up of silicone or polyurethane, come out of the tube as a flexible sealing compound that will cure after application. Most sealants are available in colors matching the roof panels. 

Butyl Tape: Butyl tape is used in a similar fashion as sealant by sealing cracks and seams on metal roofing. It’s also commonly used for trim applications. It differs from sealants because it’s in the form of one or two-sided tape and seals by compression.

Clamps: Clamps are small metal parts that are tightened and attached to the top of the metal roof at its standing seam. These clamps have screws at the top used to attach extra roofing items such as a snow retention system, solar panels, satellite dishes, signs, AC units, etc.

RoofBoot/Pipe Boot – A RoofBoot™ or pipe boot is the cone-like fitting that is installed around an exhaust pipe that exits through the roof. These products are typically made up of EPDM rubber (silicone is also available for high-temperature applications). The pipe boot, which can be purchased in a color matching the roof, is cut to fit the diameter of the exhaust pipe and is then sealed to the pipe and the metal surface.

Also See

Here are some other metal roofing articles you may be interested in.