What Are The Parts Of A Roof Called
Written by

What Are The Parts Of A Roof Called?

East Valley: 480-232-5458 | West Valley: 602-299-8851

A roof has many parts. In this guide we will break down the different components of a rood so you will be in the know. Read on to learn more.


Made from many different materials, they form the outer protection of the roof from the elements and give character to the dwelling.

Joint Covers aka Flashing

Flashing is either rigid or flexible and can be made from plastic, steel or aluminum. It stops water from flowing near the openings of the roof and can be found in the based and valleys of walls, roof vents, chimneys and vents.

Plumbing Vent

Emerging from the roof, this pipe allows air inside the plumbing system that allows wastewater to flow to the sewer or septic system.


A cardboard or Styrofoam insert between two roof rafters allowing the free flow of air over the insulation near the soffits. There needs to be a minimum of two inches of space under the decking.

Roof Vents

Enclosed and made of plastic or metal they feature fins and openings making sure the attic is ventilated. The best ones are open on all four sides and rise above roof level producing a suction effect. There also has to be an air inlet at the base of the roof. Frequently made with perforated aluminum, this closes off the lower side of the eaves.

Drip Edge

This is the moulding covering the roof edge and reduces the risk from water.

Underlay Membrane

This protective membrane goes under some or all of the asphalt shingles to prevent water infiltration caused by “ice dams” in winter.


The “V-cut” angle along the junction of two slopes of a roof.

Decking (or sheathing)

Usually made from 1⁄2-inch plywood, the decking closes and reinforces the roof structure and provides a nailbed for the shingles.

Roof Edge

All the boards running along the edge of the roof or eaves. Also known as a fascia.


The space under the roof. The attic must be ventilated to protect the roofing system against excessive heat in summer and warm moist air generated by the house in winter.


A structure located behind the higher side of a chimney (or similar projections from the roof) to divert rainwater around it.


Horizontal line at the top of the roof.

Leave a Reply

Your email address will not be published. Required fields are marked *