Need a new roof, but just starting your research journey? Do you even know what components and materials make up your roof?
Most homeowners don’t think about your roof until it’s time for a new one or there's a problem. When that time eventually comes, there’s a lot of research and information to absorb.
Well the best way to start your roofing education is with the basics of what makes a roof a roof.
For over 35 years, Bill Ragan Roofing has helped homeowners like you understand every aspect of their roof and future roofing project. So, let's start with roofing components 101 to learn all the materials that make up your roof.
By the end of this article, you'll learn about:
Roof decking (also called roof sheathing) is the wooden foundation (plywood or planks) that the rest of your roof is installed on. There are two types of roof decking: plank decking and sheet decking.
Plank decking is made up of elongated and rectangular wooden boards that are either 1x6 or 1x8, depending on the span of your rafters. Sheet decking (or sheathing) is literally flat sheets of wood (plywood or OSB) that are much wider than planks.
OSB (oriented strand board) is wood chips/strips compressed together to form a flat 7/16” sheet, while plywood comes in several different thicknesses (⅜”, ½”, ⅝”, and ¾”). Compromised roof decking must be replaced before installing your new roof, but there's no way to tell how much until after the tear off process.
Drip edge is metal flashing installed at the roof’s edges (eaves and rakes) to prevent water from getting underneath the roofing material and underlayment. Without it, your fascia board and roof decking’s edges will rot from prolonged exposure to water.
Drip edge is also required per building codes and must be installed correctly for your home to pass an inspection. Unfortunately, I see too many roofs without drip edge.
While it can be left off by laziness or lack of experience, bad roofers knowingly exclude it from their estimates to lower prices. If your roof estimate doesn’t have a line item for drip edge, I recommend finding another roofer altogether.
Ice and water shield is a waterproof membrane that protects your roof from ice and water damage if it gets under your roofing material. But unlike underlayment, it’s installed on/around certain problem areas that need added protection instead of over the entire roof deck.
Ice and water shield is mainly installed in roof valleys, around penetrations, and on roofs with a 2/12, 3/12, or 4/12 pitch. But if you live above the snowline in the US, building codes also require two rows of it along the edges of your roof to prevent leaking from ice damming.
This is considered an "upgrade" in areas like Middle Tennessee to prevent ice damming leaks when we get heavy snowfall.
Roof underlayment is a felt or synthetic material installed directly over your roof decking before the roofing material is installed. Its purpose is to provide a layer of protection for your decking if water gets underneath your roofing material.
The two types of underlayment options are felt and synthetic. Felt underlayment has been around the roofing industry longer, but synthetic is now the preferred option.
Synthetic underlayment won’t hold moisture and is more durable, holds nails better, and repels water better than felt underlayment. Felt isn’t a bad choice, but I recommend spending the extra money for the functionality and better water protection synthetic underlayment offers.
Starter shingles are a pre-cut row of roofing material installed underneath the first course of shingles. They have an adhesive to ensure the first row of shingles are sealed at the eaves and along the rakes to improve resistance against strong winds.
Starter shingles also make sure that there's material between the joints where the shingles butt against each other.
Roof flashing is a metal material that directs water away from areas (walls, chimneys, roof valleys) where the roofing material butts up against something. It’s one of the most important components, and you’ll definitely have roof leaks without it.
Roof flashing can be any metal type, but aluminum, steel, and copper are the most common metals. Steel is the most popular choice for residential roofing for its clean look, durability, and affordability.
But if you want an upgraded look, copper is well worth the investment if you have the budget. While roof flashing usually outlives the other components, it may be recommend to replace it when it’s time for a new roof depending on its condition.
Ridge capping is installed where two slopes meet to completely seal your roof system at the very top. It will be made of the same material as the main roofing material, except that it’s pre-bent to form perfectly on a roof’s ridge.
No matter which material you choose, your roof needs the associated ridge capping. Like drip edge, some roofing contractors try to avoid using proper ridge capping to keep their costs low.
Roof vents allow your attic and home to breathe properly by pulling fresh air through intake vents before pushing it out of exhaust vents. You have plenty of options, but it depends on the type of ventilation system (active and passive) you have or want.
For an active ventilation system, the most common options are turbine vents, power vents, ridge vents with a baffle, or solar-powered vents. For a passive ventilation system, you’ll have static vents (box vents), ridge vents without a baffle, or gable-end vent.
While certain vents are better for certain roof styles, I recommend an active ventilation system for performance reasons. But no matter which system or vent type, it’s crucial that your attic is ventilated properly.
A pipe boot (also called roof boot) is a type of flashing that goes around the base of the pipes coming out of your roof. Without them, water leaks down the pipes into your attic and home.
Depending on the roofing material and type of pipe, pipe boots can be synthetic rubber, plastic, lead copper, etc. While you have these options, the most common type of pipe boot used on roofs today is a synthetic rubber called neoprene.
Just know that neoprene pipe boots will need replacing every 10 years or so once cracks form. However, they’ll be cheaper than copper (or another metal), more durable than plastic, and won’t attract animals like lead.
Your roofing material is the top and main layer that makes up the bulk of the roof system. There are plenty of options, but the most popular residential roofing materials are asphalt shingles, standing seam metal roofing, cedar shake roofing, synthetic roofing, or slate roofing.
The one you choose greatly impacts your new roof's cost, aesthetic, lifespan, and warranty options. That’s why it’s important to do the research to ensure you pick the right one for you and your budget.
Now you know the components and materials that make up your roof. However, this is just roofing components 101.
So, we didn't touch on the specifics of the different type of roofing materials. And as I said, the one you choose determines things like pricing, warranties, and more.
This makes choosing the right one is one of the biggest decisions you'll make for your roof replacement. I want you to feel confident when making this decision.
That's why I wrote another article breaking down the top residential roofing materials and how to choose the right one.
Check out The Top 8 Roofing Materials to learn the pros, cons, lifespan, warranties, pricing, and more of the top residential roofing materials.