Roofing Basics

Roofing System Components

Below you'll find the basic components of a roofing system. Click the following links to learn more about each component. For an interactive tour of a Premium Roofing System, click here.

Eave Protection
Underlayment
Shingles
Edge Treatment
Valley Treatment
Flashing
Ventilation
Roof Deck

Eave Protection

Eave protection is a layer of felt or plastic placed under the shingles on eaves, in valleys, along ridges, at roof perimeters and at joint flashings. Eave protection is important for the performance of a roof, acting as both a waterproofing membrane and as extra protection against-ice damming. It protects the roof against ice that builds up during winter freeze/thaw cycles.

A high-grade asphalt membrane such as Progard Plus, manufactured by Building Products of Canada Corp., is a self-adhering waterproofing membrane designed to protect your roof - specifically on ridges, valleys, around chimneys, windows, and skylights because of its superior sealing and installation characteristics.

Gripgard, like Progard Plus, is a self-adhering waterproofing membrane created to protect the roof. Its "core" is made of fiberglass and SBS modified asphalt and is surfaced with a fine granule.

What are the differences between eave protectors?

Underlayment

Underlayment is an integral part of a roofing system. It is not required for use under all shingles. However, it is normally used as an element of a premium roofing system, offering backup protection against leaks. Underlayment acts as secondary protection against wind driven rain and as protection from moisture prior to shingle installation. It is also mandatory under all shingles to achieve a fire resistant rating. A minimum of two layers is mandatory on low slope application.

A popular felt underlayment roll is Pro 15, manufactured by Building Products of Canada Corp.

Do I need to install felt under my shingles? What does Building Products of Canada recommend?

Shingles

The proper selection and installation of roofing materials form the basis of a well-constructed roof that ensure the shingles selected perform to their maximum capabilities. But the shingles themselves determine the ultimate longevity of the roof. Premium shingles, with heavy-duty felt or fiberglass mats and thicker asphalt and granule coatings, provide longer life and, as a result, come with higher warranties.

What's the difference between Organic and Fiberglass shingles?

Some recommended shingles include BP's Eclipse laminated shingle, slate-style Europa, or heavy weight Tradition 3-tab shingles.

For a complete showcase of BP shingles, click here.

Edge Treatment

For efficient water shedding at the roof's edge, a drip edge of vinyl or metal should be installed on the eave and rake edges. The drip edge is installed under the eave protection membrane at the eaves. Along the rake, the metal drip edge should be installed over the underlayment or eave protection.

Valley Treatment

This is a common spot for snow and ice buildup, especially on roofs with lower pitches. In a premium roofing system, use of roll roofing material is required over the length of the valley.

Ice and water-proofing membrane rolls such as Progard Plus or Gripgard provide the optimum protection as the base for any valley construction and are critical in preventing problems with ice dams.

Ice damming develops as snow on the surface of the roof melts. Water runs under the edge of the roof creating a dam. Additional snow melts forming a pool against the dam causing water to back up, often getting under the shingles.

What are ice dams? How can they be avoided?

Flashing

Some of the roof's most vulnerable areas, with the highest potential for leaks include skylights, vents, chimneys, windows, and soil stacks, making waterproofing indispensable. Once again, ice and water membrane is a superb base underlayment for the flashing material. And don't forget to use roofing cements that meet or surpass CAN, CGSB or ASTM standards that are fully compatible with the shingle.

Ventilation

Proper air circulation will greatly reduce the chance of leaking, blistering, curling and many other potential problems. To tell if a home's ventilation is inadequate, several signs appear in the home's attic. Those signs include an attic that is hot and stuffy compared to the rest of the house, stagnant air, unbroken darkness indicating blocked or non-existent openings, and water stains/mold on the underside of the decking.

Why is ventilation so important?

Roof Deck

Making sure the appropriate roof deck is under the shingles you have to install is critical to ensure optimal shingle performance. The roof deck should be in good condition: dry, clean, flat, smooth and securely nailed. Plywood decks at least 1/2" thick are best. If shingles are installed over an unacceptable roof deck, it may void the manufacturer's warranty. Any part of the deck that is rotted or warped must be replaced.

To view an interactive tour of a Premium Roofing System, click here.