Residential Roof Components

What Makes Up a Roof – Your Roof Components

Tuesday, February 14th 2017

The components and systems that work together to keep water out

Water wants to get into your house.

Some people might point to the laws of physics or thermodynamics to explain how water enters your home, but all you need to know is that it wants to find a way inside the house.

It has many disguises: a gentle mist, fluffy snow or driving rain and ice, to name a few. Don’t be fooled, however – it’s all water. Once it is allowed to enter, it can potentially cause a number of challenges.

Water also has friends, especially wind and debris that help it in its mission to get into your house. Relentlessly, it finds any crack, seam or weakness and exploits it. Once it’s in, it can cause structural damage that can lead to costly repairs.

Your primary defense against water is your roof. You might think of your roof as the shingles you see every day but there is much more to it than that. An effective roofing system includes an integrated system of products and components: underlayment, ice & water protectors, drip edges, flashing, vents in addition to your shingles. These components are designed to work together to keep the elements out.

Each component is just as important as the next. Here is a look at each one and how it works to keep your home (and you) warm and dry.


You see your shingles every day. Offered in a variety of styles and colors, they can add beauty and architectural detail to your home; however, they’re doing much more than simply looking good.

Shingles are your home’s first line of defense against the weather. Most of the water that falls from the sky doesn’t make it past your shingles. Ideally, it falls off the eaves, into the gutters, and away from areas where it can cause any potential damage.

Shingles are made of tough materials: fiberglass mat, asphalt coating and ceramic-coated granules that collectively help to protect your home from the elements.

In addition to roofing shingles, manufacturers also usually offer specialized accessory shingles that are part of the overall roof system. They can include:

  • Starter shingles are installed underneath the first row of shingles on the lower eave These products, such as IKO Armour Starter and Leading Edge Plus, are intended to provide added protection to this critical area. They are cut to size, making installation faster, and include a sealing strip at the bottom edge. This helps to form a tight seal with the first course of shingles.
  • Ridge cap shingles are specially designed to cover the gap where shingles meet at the ridge of the roof and can also be installed over ridge vents.


Just below the shingles is the underlayment – a protective layer of asphalt-saturated felt or synthetic material. Rolled directly onto your roof deck, the underlayment forms a protective barrier to help keep the roof deck dry.

Any water that manages to make its way beneath your shingles will have to get past the underlayment to go further. IKO underlayment offerings include RoofGard-Cool Grey, and Stormtite®.

Ice & Water Protectors

Your roof can be most vulnerable to water intrusion on the eave edges, ridges and valleys. These are the areas where water can collect and ice dams can occur. It also tends to be where the wind is strongest. These areas can also have natural seams that water can exploit.

Ice & water protectors, such as IKO ArmourGard, GoldShield, and StormShield™, provide added protection and sealing to these areas. Made of a strong membrane material, they work to help keep water out of those potentially vulnerable areas.

Drip Edge & Flashing

The drip edge is a thin strip of metal or plastic installed at the edges of your roof, below the underlayment, to facilitate water runoff and protect the roof deck from water damage.

Also made of metal, flashing is used in transition areas between the roof and protrusions such as: walls, dormers, chimneys and skylights. Flashing helps direct water away from the seams in these areas. It is also often used in roof valleys.


Last, but certainly not least, is ventilation, which is critical to the health and performance of your roof. A poorly ventilated roof can lead to a number of problems inside and out.

On the inside, water vapor produced by daily activity – showers, cooking and even breathing – can condense inside your attic.

To help prevent these problems, proper ventilation is crucial. Good ventilation promotes airflow underneath the deck, helping to regulate the temperature and keep it dry.

These are the basic components of most roofs. The products recommended may vary depending on the weather in your region, as well as the slope and complexity of your roof.

Like any system, your roof is only as strong as each individual component. When having your roof replaced, consider an IKO Shield Pro Plus Contractor, and ask them about the products they recommend.


IKO Shield Pro Plus contractors are independent contractors responsible for the quality of their workmanship and are not agents or representatives of IKO

Read our previous blog post: