Roofing Guide to the International Building Code (IBC)

By Jack Gray, Roof Online Editor • Last updated February 10, 2023

Introduction

This page references the 2018 International Building Code. Although it isn’t the newest version, the 2018 version of the code is currently the most commonly used.

Sections of the code which reference roofing or roof-adjacent aspects of construction are presented on this page. We also provide links to the actual building code for every chapter below so you can see the actual language of the sections you’re interested in.

You may be looking for our Roofing Guide to the International Residential Code.

For an excellent guide to the entire IBC, consider getting a copy of Building Codes Illustrated: A Guide to Understanding the 2021 International Building Code by Francis D. K. Ching and Steven R. Winkel. (Link goes to the book’s Amazon page.)

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Note on Amendments to the International Building Code

Always check with your local building inspector’s office or website to be certain which version of the building code is in effect in your area.

New versions of the model International Building Code are produced every 3 years, but they are not adopted or put into effect by local authorities every 3 years. In fact, they are not adopted with any consistency from country to country, state to state, or even city to city.

An important thing to be aware of is the fact that the majority of the governing authorities which adopt the codes do so with amendments.

The codes produced by the International Code Council are model codes, which means that they are simply standardized templates that the authorities in actual jurisdictions can use as a foundation for their building codes. Some places will adopt the codes as they are, without amendments, but this is not very common.

Local authorities can (and they do!) add things, remove things, change the language, and make exceptions to the model code, so it’s not enough to simply know which version of the model code has been adopted.

Please see our page Building Codes & Roofing 101 • Important Facts & Guidelines for more information.

Chapter 1 – Scope and Administration

See the full code for Chapter 1 on the ICC website.

See the full code for Chapter 1 on the UpCodes website.

Section 104 Duties and Powers of Building Official

104.10 Modifications (Roof Online Note: This section gives the building inspector leeway when it comes to enforcing the code. It allows you to present reasonable requests for code requirement modification if strictly following the code is impractical but the intent and purpose of the code will still be satisfied.)
104.11 Alternative materials, design and methods of construction and equipment

Section 105 Permits

105.1 Required
105.2 Work exempt from permit

Section 106 Floor and Roof Design Loads

106.3 Restrictions on loading

Section 107 Submittal Documents

107.2.4 Exterior wall envelope

Section 110 Inspections

110.3.6 Weather-exposed balcony and walking surface waterproofing

Chapter 5 – General Building Heights and Areas

See the full code for Chapter 5 on the ICC website.

See the full code for Chapter 5 on the UpCodes website.

Section 503 General Building Height and Area Limitations

503.1.4 Occupied roofs

Section 504 Building Height and Number of Stories

504.3 Height in feet

Chapter 6 – Types of Construction

See the full code for Chapter 6 on the ICC website.

See the full code for Chapter 6 on the UpCodes website.

Section 603 Combustible Material in Types I and II Construction

603.1 Allowable materials

Chapter 7 – Fire and Smoke Protection Features

See the full code for Chapter 7 on the ICC website.

See the full code for Chapter 7 on the UpCodes website.

(Roof Online Note: This chapter mentions roofs about 150 times; not all subsections are listed here.)

Section 705 Exterior Walls

705.11 Parapets

Section 706 Fire Walls

Section 711 Floor and Roof Assemblies

Section 712 Vertical Openings

712.1.15 Skylights

Section 720 Thermal- And Sound-Insulating Materials

720.5 Roof insulation

Chapter 9 – Fire Protection and Life Safety Systems

See the full code for Chapter 9 on the ICC website.

See the full code for Chapter 9 on the UpCodes website.

Section 910 Smoke and Heat Removal

910.3 Smoke and heat vents

Chapter 10 – Means of Egress

See the full code for Chapter 10 on the ICC website.

See the full code for Chapter 10 on the UpCodes website.

(Roof Online Note: This chapter covers roof hatches, access stairs, and access ladders.)

Section 1011 Stairways

1011.12 Stairway to roof
1011.12.2 Roof access
1011.13 Guards
1011.16 Ladders

Section 1015 Guards

1015.7 Roof access

Chapter 12 – Interior Environment

See the full code for Chapter 12 on the ICC website.

See the full code for Chapter 12 on the UpCodes website.

Section 1202 Ventilation

1202.2 Roof ventilation
1202.2.1 Ventilated attics and rafter spaces
1202.3 Unvented attic and unvented enclosed rafter assemblies

Chapter 13 – Energy Efficiency

See the full code for Chapter 13 on the ICC website.

See the full code for Chapter 13 on the UpCodes website.

(Roof Online Note: This chapter used to be called “Energy Conservation”. It basically tells you that building design and construction is governed by the International Energy Conservation Code.)

Chapter 14 – Exterior Walls

See the full code for Chapter 14 on the ICC website.

See the full code for Chapter 14 on the UpCodes website.

Section 1404 Installation of Wall Coverings

1404.4 Flashing

Chapter 15 – Roof Assemblies and Rooftop Structures

See the full code for Chapter 15 on the ICC website.

See the full code for Chapter 15 on the UpCodes website.

(Roof Online Note: This is the main roofing chapter of the code. In particular, note that the Section 1507 subsections for each different type of roofing material address deck requirements, slope, fasteners, underlayment, and flashing for that specific roof type.)

Section 1502 Roof Drainage

Section 1503 Weather Protection

1503.2 Flashing
1503.3 Coping
1503.4 Attic and Rafter Ventilation
1503.5 Crickets and Saddles

Section 1504 Performance Requirements

Section 1505 Fire Classification

Section 1506 Materials

Section 1507 Requirements for Roof Coverings

1507.1.1 Underlayment
1507.1.2 Ice Barriers (Roof Online Note: “Ice Barriers” covers the installation requirements for ice and water shield.)
1507.2 Asphalt shingles1507.2.8 Flashings 1507.2.8.2 Valleys 1507.2.8.3 Drip Edge
1507.3 Clay and concrete tile
1507.4 Metal roof panels
1507.5 Metal roof shingles
1507.6 Mineral-surfaced roll roofing
1507.7 Slate shingles
1507.8 Wood shingles
1507.9 Wood shakes
1507.10 Built-up roofs
1507.11 Modified bitumen roofing
1507.12 Thermoset single-ply roofing (Roof Online Note: This section covers EPDM roofing.)
1507.13 Thermoplastic single-ply roofing (Roof Online Note: This section covers PVC and TPO roofing.)
1507.14 Sprayed polyurethane foam roofing
1507.15 Liquid-applied roofing
1507.16 Vegetative roofs, roof gardens and landscaped roofs
1507.17 Photovoltaic shingles
1507.18 Building-integrated photovoltaic roof panels

Section 1508 Roof Insulation

Section 1509 Radiant Barriers Installed Above Deck

Section 1510 Rooftop Structures

Section 1511 Reroofing

(Roof Online Note: This section covers the requirements for replacing an existing roof or installing a new roof over an old roof (roof recovery). It also tells you how many roofs or how many layers of roofing you can put down on top of one another on a building and under what conditions.)

Chapter 16 – Structural Design

See the full code for Chapter 16 on the ICC website.

See the full code for Chapter 16 on the UpCodes website.

(Roof Online Note: This chapter used to be called “Structural Loads”.)

Section 1603 Construction Documents

Section 1606 Dead Loads

Section 1607 Live Loads

Section 1608 Snow Loads

Section 1609 Wind Loads

1609.5 Roof systems

Section 1611 Rain Loads

Section 1613 Earthquake Loads

1613.3 Ballasted photovoltaic panel systems

Chapter 17 – Special Inspections and Tests

See the full code for Chapter 17 on the ICC website.

See the full code for Chapter 17 on the UpCodes website.

Section 1705 Required Special Inspections and Tests

1705.2.2 Cold-formed steel deck
1705.11.3 Wind-resisting components

Chapter 18 – Soils and Foundations

See the full code for Chapter 18 on the ICC website.

See the full code for Chapter 18 on the UpCodes website.

Section 1805 Dampproofing and Waterproofing

Chapter 21 – Masonry

See the full code for Chapter 21 on the ICC website.

See the full code for Chapter 21 on the UpCodes website.

Section 2113 Masonry Chimneys

Chapter 22 – Steel

See the full code for Chapter 22 on the ICC website.

See the full code for Chapter 22 on the UpCodes website.

Section 2210 Cold-Formed Steel

2210.1.1 Steel decks
2210.1.1.2 Steel roof deck

Chapter 23 – Wood

See the full code for Chapter 23 on the ICC website.

See the full code for Chapter 23 on the UpCodes website.

(Roof Online Note: This is the rafter chapter, among other things. Includes joist and rafter span tables. Also covers wood panel (plywood, OSB) roof sheathing requirements.)

Section 2303 Minimum Standards and Quality

2303.1.5 Wood structural panels
2303.1.6 Fiberboard
2303.1.6.2 Roof insulation

Section 2304 General Construction Requirements

2304.4 Floor and roof framing
2304.8 Floor and roof sheathing (Roof Online Note: This subsection covers plywood and OSB sheathing. See Table 2304.8(3) for minimum allowable panel thickness by span and load.)
2304.9 Lumber decking
2304.10 Connectors and fasteners
2304.11 Heavy timber construction
2304.11.4 Roof decks

Section 2308 Conventional Light-Frame Construction

2308.7 Roof and ceiling framing

Chapter 24 – Glass and Glazing

See the full code for Chapter 24 on the ICC website.

See the full code for Chapter 24 on the UpCodes website.

(Roof Online Note: This is the chapter you want for information about skylights.)

Chapter 26 – Plastic

See the full code for Chapter 26 on the ICC website.

See the full code for Chapter 26 on the UpCodes website.

(Roof Online Note: “Foam plastic insulation” covers polyisocyanurate, polystyrene, and polyurethane foam insulation.)

Section 2603 Foam Plastic Insulation

2603.6 Roofing

Section 2606 Light-Transmitting Plastics

Section 2609 Light-Transmitting Plastic Roof Panels

Section 2610 Light-Transmitting Plastic Skylight Glazing

Chapter 31 – Special Construction

See the full code for Chapter 31 on the ICC website.

See the full code for Chapter 31 on the UpCodes website.

(Roof Online Note: This chapter covers membrane structures made out of materials like PTFE (Teflon) fabric; awnings, canopies, solar energy systems, greenhouses, and fixed, retractable or rotating sun control devices.)

Chapter 35 – Referenced Standards

See the full code for Chapter 35 on the ICC website.

See the full code for Chapter 35 on the UpCodes website.

(Roof Online Note: This chapter lists every official standard referenced in the code. Over 65 standards have to do with roofing.)