Roofing Components: What You Want to Know Before Reroofing

Roofing Components

Everyone needs a roof over their head. It’s the most important and often overlooked component of a home or business. When you go to replace an old roof, it may feel overwhelming because most people don’t know much about a roof – not having spent much time up there.

A qualified roofing contractor will go over all aspects with you to make sure you understand what you’re getting. To get you started, here are some tips to help you know what to look for and what you need to know about your roof.

Basic Roofing Components

There are five basic roofing components of a steep-slope roof system. A steep slope system is a slope of 25% or more.

  1. Roof Covering: The roof covering is just what is outermost on top of your roof: asphalt shingles, tile, slate, or a metal and the underlayment protecting the roof sheathing from all types of weather.
  2. Sheathing: Sheathing is boards or sheet material that is nailed or screwed to the roof’s rafters. It’s also called the roof decking. This is what makes the roof have a shape.
  3. Roof Structure: The roof structure is made up of rafters and trusses which support the sheathing – the inside of which will make up your attic.
  4. Flashing: Flashing is a sheet metal or material that gets installed around your roofing system’s joints and valleys to help prevent water seepage in all the cracks and crannies.
  5. Drainage: Drainage is more like a system which is comprised of the slope of the roof, the layout, and the shape that make it shed water instead of letting water stand. Your gutter system aids in this process.
Cross-section of roof
Roofing Components: Cross-section of roof

Choosing a Roofing System

Of course, there are many options for roof coverings. You can choose from a variety of roofing materials including tiles, metal panels, and wood shingles.

However, the overwhelming majority of roofs in North America are finished with asphalt shingles. These can be reinforced with organic or fiberglass materials. Asphalt shingles reinforced with organic felts have been around for a long time, but fiberglass reinforced shingles are the dominant shingle on the market.

Organic shingles are made of a wood fiber base saturated with asphalt and coated with mineral granules. Fiberglass shingles are made of a fiberglass mat with top and bottom layers of asphalt and also coated with mineral granules.

All asphalt shingles are rated for their fire-resistance by class: A, B, and C, with A being the most fire-resistant. The reason fiberglass shingles are more popular is that they have an A rating. Most organic shingles have a C rating.

These two types of shingles look the same. They are both offered in grades that offer a texture. You can find zinc or copper-coated ceramic granules to protect against algae. Both are available in a wide array of colors.

Roofing Standards

It’s important to note that asphalt shingles physical characteristics can vary. You want to use shingles that comply with ASTM standards – that’s the American Society for Testing and Materials.

These standards ensure that the shingles you use meet high safety and construction standards. Not all shingles on the market meet these standards. However, if they do, it’s typically noted in the product literature and on the package.


Thinking about having your roof replaced may leave you feeling like you don’t know enough about the process or the products. It helps to have a bit of knowledge and insight about basic roofing components before you undertake this big job.

If you live in Southeast Michigan, please give us a call. We would be honored to help.

We’re here whenever you need us.

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