The Many Layers that Make Up a Shingle Roof

Since the shingles are the visible part of a completed roof, many people think that they’re all there is to roofing. Ainger Group, a roofer in Barrie, notes that in reality, the shingles are just the top of several layers of materials that are applied. The other layers provide essential protection against a variety of threats.

Roofer in Barrie Explains Roof Layers


These are the most common outer layer on a Canadian residential roof. A variety of styles exist to create specific textures, colour combinations, and effects. Other special shingles are used for specific situations, such as starting the job at the eave and raking the edge of the roof or to cover any hips and ridge caps present.


Whenever an object (such as a chimney) protrudes from the roof, flashing must be used to join it to the roof. This keeps water from running down the outside of the chimney or other protrusions and past the roof layers.

Along with chimneys, you should find flashing around things like skylights, roof vents, plumbing vents, satellite dish mounts, and other such items. These items are sometimes called “protrusions” by roofers.

Flashing is also used where dormers connect to the rest of the house, as well as where other structural extensions meet. This provides extra protection against leakage at these key points.


This layer used to be made of felt that has been saturated with asphalt, but synthetic versions have come to the fore. It provides some fire resistance, protects the roof decking from water that has made it past the shingles, and protects the shingles from any resin that is released by the roof deck.

Ice and Water Protector

In Canada, you’ll surely find this under the shingles of a good roof, along with the standard underlayment. Sometimes, it is only applied to the edges of a roof. It helps to prevent ice dams in the winter, and in warmer times, helps protect the roof from wind-driven rain. It is able to self-seal around the nails used in roofing, so a watertight seal is maintained.


This is the base layer of the roof, upon which everything else must sit. It is typically made of plywood or OSB (oriented strand board). Protecting it from moisture and rotting is one of the chief duties of all of the other materials. This is typically only replaced in the event of serious, widespread damage.

Roofs have other aspects, such as gutters and fascia boards, that are not specifically roofing materials. A roofer in Barrie like Ainger Roofing will typically service all of them if the need arises.

If you’re looking for a roofer in or around Barrie, Ontario, contact us today. We will be happy to give you a quote and get your roof in order.