§ Chapter 9 IRC 2021
Roof Assemblies
10 entries from Chapter 9 of IRC 2021, organized by section number. Each entry covers what the code requires, why it exists, what inspectors look for, and common mistakes.
§ 01 Sections
All 10 entries.
Sorted by section number. Click any row for the full entry — answer, requirements, edition diff, related sections.
Section
Title
Question
R901.2
Roof Coverings Must Protect the Building From Weather
R901.2
Does the IRC require a roof covering on every dwelling?
Does the IRC require a roof covering on every dwelling?
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R903.2.1
Flashing Is Required Where Roofs Meet Walls, Chimneys, and Penetrations
R903.2.1
Where is roof flashing required by IRC 2021?
Where is roof flashing required by IRC 2021?
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R903.4
Roofs Must Drain Without Damaging the Building
R903.4
Does the IRC require gutters or roof drainage?
Does the IRC require gutters or roof drainage?
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R905.1.1
Roof Underlayment Is Part of the Required Roof Assembly
R905.1.1
Is roofing underlayment required by IRC 2021?
Is roofing underlayment required by IRC 2021?
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R905.1.2
Ice Barriers Are Required Where There Is a History of Ice Dams
R905.1.2
When is an ice barrier required on a roof?
When is an ice barrier required on a roof?
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R905.2.2
Asphalt Shingles Need the IRC Minimum Roof Slope
R905.2.2
What is the minimum roof slope for asphalt shingles under IRC 2021?
What is the minimum roof slope for asphalt shingles under IRC 2021?
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R905.2.6
Asphalt Shingles Need Approved Fasteners and Placement
R905.2.6
How many nails are required for asphalt shingles by code?
How many nails are required for asphalt shingles by code?
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R905.2.8.2
Roof Valleys Need Lined or Approved Closed-Valley Protection
R905.2.8.2
What does code require for roof valley flashing?
What does code require for roof valley flashing?
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R905.2.8.5
Drip Edge Is Required at Eaves and Rakes for Asphalt Shingle Roofs
R905.2.8.5
Is drip edge required by IRC 2021?
Is drip edge required by IRC 2021?
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R908.3
Reroofing Must Follow IRC Overlay and Tear-Off Limits
R908.3
Can you put new shingles over old shingles under IRC 2021?
Can you put new shingles over old shingles under IRC 2021?
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§ 02 Chapter navigation