Roofing glossary
Roofing Glossary for Homeowners
Plain-language definitions of the terms on your roofing quote.
The short answer: If your roof has years left and the damage is in one area, repair it. If shingles are failing across the roof or the same leaks keep returning, a replacement saves money over time. We tell you which one applies, with photos.
The short version
Roofers use a lot of shorthand. This glossary explains the terms you will see on an inspection report or quote, in plain language.
A roofing glossary defines common terms such as flashing, underlayment, decking, ice and water shield, square, valley and ridge vent so homeowners can understand an estimate. A square is 100 square feet of roof area, and flashing is metal or similar material that seals joints where water could enter.
Roof structure terms
- Decking (sheathing): the boards or panels the roofing is fastened to.
- Underlayment: a protective layer between the deck and the shingles.
- Eave: the lower edge of the roof that overhangs the wall.
- Rake: the sloped edge of a gable roof.
- Ridge: the horizontal peak where two slopes meet.
- Valley: the inside angle where two slopes meet and water flows together.
- Pitch: how steep the roof is, usually written as rise over run.
- Fascia and soffit: the trim board at the eave and the underside of the overhang.
Material terms
- Square: 100 square feet of roof area, the unit most quotes use.
- Architectural shingle: a thicker, layered asphalt shingle. See best shingles for Indiana.
- 3-tab shingle: a flat, single-layer asphalt shingle.
- Class 4 impact-resistant shingle: the highest rating under the UL 2218 impact test.
- Standing seam: a metal roof system with raised seams. See metal roofing.
Water-protection terms
- Flashing: metal or similar material sealing joints at chimneys, walls, valleys and penetrations. See chimney flashing repair.
- Ice and water shield: a self-adhering membrane used at eaves and valleys. See ice dams in Indiana.
- Pipe boot: the collar that seals a vent pipe through the roof.
- Drip edge: metal at the roof edge that directs water into the gutter.
Ventilation terms
- Intake vent: lets outside air into the attic, usually at the soffit.
- Exhaust vent: lets warm air out, such as a ridge vent.
- Baffle: keeps insulation from blocking intake airflow. See roof ventilation.
Insurance and contract terms
- Actual cash value (ACV): replacement cost minus depreciation. See ACV vs replacement cost.
- Deductible: the amount you pay before coverage applies.
- Adjuster: the insurer’s representative who evaluates a claim.
- Tear-off: removing the old roofing before installing the new.
- Change order: a written change to the agreed scope and price.
Read more in our insurance claim guide and guide to choosing a roofer.
Roofing glossary questions
What is a square in roofing?
A square is 100 square feet of roof area and is the unit most quotes use.
What is flashing?
Metal or similar material that seals joints where water could enter, such as chimneys and valleys.
What is underlayment?
A protective layer between the roof deck and the shingles.
What is decking?
The boards or panels the roofing is fastened to.
What is a valley?
The inside angle where two roof slopes meet.
What is ice and water shield?
A self-adhering waterproof membrane used at eaves and valleys.
What is a tear-off?
Removing the old roofing before installing new roofing.
What is actual cash value?
Replacement cost minus depreciation.
What is a change order?
A written change to the agreed scope and price of a job.
What is a Class 4 shingle?
The highest rating under the UL 2218 impact test.
Related:
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123 Main Street, Indianapolis, IN 46204
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