Home / 27 Roofing Terms & What They Mean

27 Illinois Roofing Terms &What They Mean

Stay informed and learn 27 terms that roofers commonly use when talking about your roof repair or replacement.

Request a Phone Call From Your Local Roofing Professionals
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.


Being well-informed can help you when it’s time to hire a Tinley Park roofing contractor. Knowing what your roofer is talking about can help you know what questions to ask and what boxes to check.

Here are some common roofing terms and what they mean.

1. Slope (or Facet, Section)

A single roof surface. For example, a completely flat roof would have only 1 facet.

2. Hip (or Ridge)

Where two roof slopes meet, forming an upside down V.

3. Peak

The point where two roof slopes meet. The top of a ridge.

4. Ridge Vent

An opening on the ridge of the roof that allows hot air to escape from the attic. Ridge vents help prolong the life of your roofing materials.

5. Ridge Cap (or Hip Cap)

Shingles that are laid overtop of a roof hip or ridge.

6. Turtle Vent (or Box Vent)

A simple vent that sits high on a slope of your roof, as close to the ridge as possible. While box vents get the job done, they aren’t quite as efficient as ridge vents. This is because hot air rises, and ridge vents are at the peak of the roof.

7. Valleys

Where two roof slopes meet inward, forming a V-shaped trough.

8. Pitch

Pitch refers to how steep a roof is. If the pitch of your roof is 6/12, that means your roof rises 6 inches for every 12 inches towards the peak. 

9. Cut-Up

How many slopes (or facets, sections) a roof is divided into. The more complex your roof, and the more slopes it has, the higher the “Cut-Up” is.

10. Rake Edge

A side of the roof where two slopes meet to form an upside down V. Typically it is made out of a wooden material.

11. Eaves / Eave Edge

Eaves are the part of the roof that overhangs the exterior walls. The edge of roof eaves are called fascia, and the underside of a roof eave is called soffit. 

12. Soffit

Soffit is the underside of an eave that hangs off of the roof. If you look straight up at the eaves of your roof, you are mostly seeing soffit. Soffit is sometimes vented to allow air intake, which helps protect roofing materials from weather damage. 

13. Drip Edge / Gutter Apron

Drip edge is a thin metal sheet that goes on the edges of your roof to protect the fascia from water damage. In southern Illinois, and most southern states, drip edge is used on both the eave edges (where gutters sit) and rake edges of the roof.

However, in northern Illinois and states further north, we use gutter aprons on the eave edges of the roof. This is to deal with ice damming, which is a problem that is unique to northern climates. A gutter apron sits underneath the roof underlayment, or ice and water barrier, and helps direct water away before it has a chance to freeze and cause damage.

14. Starter Strip

Starter Strips are shingles that are especially designed to go on the eave edges and sometimes rake edges of your roof. They are specialized shingles made to cover shingle joints and cutouts, and are extra durable to prevent shingles from being blown off in the wind. 

15. Fascia

Fascia is the wooden edge of an eave that gutters are attached to.

16. Gutters

Gutters are metal troughs that are attached to the eave edges of your roof in order to catch rainwater. They are typically made out of aluminum. A good gutter system is crucial to ensure that rain water is diverted away from the sides and foundation of your house.

17. Penetration

Anything that protrudes through the surface of the roof. For example, vents, shingles, skylights, and chimneys are all considered penetrations. Since penetrations need to be worked around during installation, and flashing needs to be installed, they increase the labor cost of roofing projects. 

18. Flashing

A thin metal sheet that diverts water away from vulnerable areas in your roof. Flashing is usually installed around penetrations of the roof, like chimneys, skylights, vents, etc. It is also installed in valleys, since water naturally gathers in valleys.

19. Pipe Boot / Pipe Jack

A type of flashing that is specifically designed to seal off pipes that penetrate through your roof. These pipes are to provide ventilation for bathroom fans, dryer vents, or your home’s plumbing system. 

20. Underlayment

Underlayment is a thin synthetic material or asphalt-saturated felt that goes over your roof deck and underneath the shingles. It is an additional water-shedding barrier that prevents water from getting into the roof deck and causing rot and leaks.

21. Ice and Water Shield

Ice and water shield is a waterproof membrane that is installed underneath shingles over areas on the roof where water naturally gathers, such as eaves and valleys. It is mostly used in northern states to help prevent ice damming. 

22. Roof Deck

Roof decks are the surface that shingles, underlayment, and all other roofing materials are installed on top of. Typically roof decks are made out of plywood or OSB. 

23. Rafters

Rafters (and sometimes Trusses) are like the skeleton of your roof. They are the wooden beams that the roof decking is installed onto and provide structural support to the entire roof. 

24. Squares

You might hear your roofer saying that your roof is “20 squares.” A square is simply equal to 100 square feet. If your roof has 2000 square feet of surface area, it’s a 20 square roof. 

25. Roofing System

Roofs are made up of several different components, such as insulation, ventilation, ice and water shield, underlayment, shingles, etc. Many roofers mix and match materials from different manufacturers. They might use one manufacturer for shingles, and another for underlayment. 

A roofing system is where all of the roofing companies are made by the same manufacturer. This is effective because these components are tested together for quality and designed to work together. A roofing system even includes instructions from the manufacturer on how to install the materials for maximum effectiveness. At Allied Restoration Contractors, we are proud to hold certifications with GAF, CertainTeed, and Owens Corning. 

26. Walkable

If you can walk on the roof unaided when the roof is dry, your roof is “walkable.” If your roof has a steep pitch, and safety harnesses and other aids are required to complete the roof replacement, it’s less walkable. The less walkable a roof is, the higher the labor cost will be for repairs or replacement.

27. Impact Rating

Impact ratings determine how strong a shingle is against impact (hail.) Only some manufacturers produce shingles with impact ratings. 


Hopefully this article helped you understand the different components of a roof and will help you understand what your roofer is talking about.

If you are in need of a roof replacement and are still looking for quotes, get in touch with Allied Restoration Contractors. We look forward to serving you!

1655 South Oak Park Ave, Tinley Park, IL 60477

Mon-Fri 9AM - 5PM
Sat 9AM - 2PM

© 2024 Allied Restoration Contractors