What Are The Components Of A Metal Roof?
What Are The Components Of A Metal Roof?
Metal roofing is made from three basic components: Metal Panels, Fasteners & Clips, Underlayment, Sealant, Trim, and Closures.
- Metal Panels- A metal roof’s biggest (and most obvious) part is the actual metal panels themselves. These panels are made of aluminum, galvanized steel, zinc, or stainless steel.
Aluminum is the most common metal used for metal roofs today because it is lightweight and durable. Galvanized steel and zinc are also popular choices. Galvanized steel has a strong resistance to rust, but it is vulnerable to dents.
Zinc is less likely to dent than galvanized steel, but it does not resist rust as well because water can get into the zinc coating and oxidize the underlying metal. Stainless steel resists corrosion and rusting, but it tends to be more expensive than aluminum or galvanized steel (and zinc).
- Fasteners & Clips- These are often the same but can also be separate. Fasteners are the screws or nails that attach the metal panels to a roof’s framing system. They come in a variety of different styles, including the following:
- a) Standing Seam Clips- These clips look like large staples and can be installed with nails or screws. They are meant for concealed fastener systems and work very well with shingles.
However, because of their large size (usually between 1/4″ to 3/4″), they can make visible fastener systems look very bulky and unattractive.
- Underlayment- Underlayment is the material that goes underneath the metal panels on a roof before the actual shingles or metal panels go on top. Most underlayment is made of fiberglass, and it comes in rolls as shingles do.
The most popular choice for underlayment today is TPO, which stands for Thermoplastic Polyolefin. It is usually black and provides a great base for any type of roofing material.
- Sealant- Metal roofing sealant seals leaks instead of just stopping or slowing down water penetration like many other roof systems do (most roofing sealants are only able to prevent water penetration).
Metal roofing sealant is a rubber that contains asphalt and works well in any climate. It comes in a variety of different thicknesses, ranging from 1/16″ to 1/8″.
It is black and does not come in rolls like the other metal roofing components, but it can be bought by the gallon and applied with a paintbrush.
- Trim- Metal roofing trim is usually installed around skylights, vents, or pipes to cover them up. There are many different kinds available today:
- a) Roofing Flashing- This type of trim is used around valleys (where two slopes of a roof meet). It is made of sheet metal.
- b) Flashing- This type of trim is used for other types of roofing, such as chimneys, skylights, or pipes. It comes in many different shapes and sizes. It can also be made from a variety of different materials (the most common choices are copper, aluminum, stainless steel, or galvanized steel).
- c) Shingle Flashings– These are used around chimneys or other areas where shingles overlap (usually 3″ to 6″ wide). They can be made from many different materials (they commonly come in copper or aluminum).
- d) Spacing Strips- These are used when multiple rows of shingles overlap to prevent or slow down water penetration (made from TPO, rubber, or plastic).
- Closures- These components are the ones that come at the end of a metal roof project and are meant to finish it off and protect against possible water leaks.
The two most popular types of closures include drip edges (aluminum or copper) and skylight screens (copper or aluminum). Skylight screens are also available in a third option: stainless steel.
