Do you know what goes into installing the roof above your head? Whether you’re thinking about replacing your roof or just wondering about the one you have, understanding your roof’s components will help you understand how they work together to protect your home.

We’ve created this diagram (including definitions) to help you understand the components of your roof:

Gable

The gable is the triangular part of your wall between the two pitches. Gables come in a variety of styles including L-shape, false front, and classic. Not all buildings have gables (especially commercial buildings with flat roofs), but they’re common for residential homes.

Rake and Rake Board (Fascia)

The rake describes the sloped sides at a gable end. There are three types of rakes:

1. Exposed Rakes: These are often on sheds or cottage homes where the rafters and framing are left open.
2. Closed Rakes: These are boxed in. The soffit is usually smaller than six inches in width and a fairly simple design. It’s one of the most common designs.
3. Overhanging Rakes: With this type, the soffit is typically larger than six inches in width and incorporates more detail.

The rake board – otherwise known as fascia – is installed to keep water from getting behind it and damaging the roof.

Valley

The valley is the junction point where two roof plains meet. Valleys can be especially prone to leaks, which is why it’s important they be sealed properly.

There are three main ways roofers can seal a valley:

1. Open Valley: This method is used with three-tab and slate shingles.
2. Closed-Cut Valley: This technique is generally more aesthetically appealing.
3. Woven Valley: This is the most waterproof design, since it blends open and closed approaches.

Whatever type of valley your roofer favors, they need to install a leak barrier below to provide additional protection.

Roof Deck

The roof deck is the base of your roof. Residential roof decks are typically made of wood and sheathed with plywood, preferred for its durability and low cost. How thick the plywood needs to be will vary by slope, spacing, and the weight of materials being put on top. Wider rafters, heavier shingling, and lower slopes – for example – will all require thicker plywood.

Underlayment and Roof Deck Protection

The underlayment and roof deck protection is critical for defending against water damage. Pay attention to the type of underlayment your roofer uses. Most synthetic felts – such as those made from polyethylene or laminated waterproof papers – can trap moisture and prevent it from escaping.

Ventilation System

Your attic needs to be properly ventilated to keep insulation in good shape, protect your shingles, and reduce energy bills. In the heat of summer, the temperature in a poorly ventilated roof can soar past 70 degrees Celsius! The right ventilation system will balance the air intake (the air leaving your soffits) and outtake (that near the roof ridge).

Ridge Cap

Ridge caps are a layer of shingles that cover the ridge of the roof, preventing leakage and accentuating your home’s appearance by adding dimension. Ridge cap shingles need to be properly installed to ensure the best results and prevent issues like cracking.

Metal Drip Edge

Drip edge is installed along the eaves and rakes of a roof to:

• Provide a solid base for shingles, discouraging them from curling over the fascia and breaking or cracking.
• Prevent water from getting behind your eavestrough. Water penetration can lead to costly repairs down the road if not prevented or caught early.
• Cover gaps to keep animals out, deterring them from chewing at your fascia and making their way into your attic where they can be notoriously destructive.

Eavestrough

An eavestrough – otherwise known as a rain gutter – is a trough used to collect and divert water away from the edge of your roof and towards the downspout, sending it away from your home to protect your foundation.

Flashing

Flashing needs to be installed around potential weak spots – including around chimneys, vents, or skylights – to keep water from sneaking in. It’s important that flashing always be installed so seams face downhill. If they’re facing uphill, water will be able to get in. Sometimes, flashing can be installed as a continuous piece (around skylights for example). Other times though, it will be need to be cut to the shape (as is the case with features like pipe vents) before being fitted in.

Shingles

When it comes to roofing, shingles are the final piece of the puzzle. Shingles serve a variety of purposes including. Shingles play an important role in protecting your home and roof – providing a barrier against rain, snow, and wind to keep your insulation and anything inside the home safe.