2015-2018 international residential code

© 2020 Colorado Code Consulting, LLC 1

2015-2018 International Residential CodeChapters 1-10

Gil Rossmiller – Colorado Code Consulting, LLC

2

Instructor

Gil RossmillerIn the construction industry for over 40 yearsICC – IRC Plumbing & Mechanical Code Development Committee ICC – Commercial Energy Code Development Committee 2003-2016 Building Official Parker, Colorado

© 2020 Colorado Code Consulting, LLC


The Fine Print! There are times

when the code is vague.

You may get my opinion.

You have yours! AHJ makes final

determination

International Residential CodeScope Detached One

Family Dwellings Detached Two

Family Dwellings Townhouses


IRC Format Part I –

Administrative Part II – Definitions Part III – Building

Planning and Construction

Part IV – Energy Conservation

Part V - Mechanical Part VI – Fuel Gas Part VII – Plumbing Part VIII – Electrical Part IX – Referenced

Standards


Part IIIBuilding Planning & Construction Ch. 3 – Building

Planning Ch. 4 – Foundations Ch. 5 – Floors Ch. 6 – Wall

Construction Ch. 7 – Wall

Covering

Ch. 8 - Roof-Ceiling Construction

Ch. 9 – Roof Assemblies

Ch. 10 – Chimneys & Fireplaces



R101.2 ScopeThe provisions of the IRC shall apply to:Construction RepairAlteration EquipmentMovement Use and Occupancy Enlargement LocationReplacement Removal and Demolition

of detached one and two family dwellings and multiple single-family dwellings (townhouses) not more than 3 stories in height with a separate means of egress and their accessory structuresnot more than 3 stories in height.


Definitions - R202

Dwelling UnitA single unit providing complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation.


Definitions - R202Townhouse

A single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof and with open space on at least two sides.

R101.2 Scope (2018)Exception: The following shall be permitted to be constructed in accordance with this code where provided with a residential fire sprinkler system complying with Section P2904:1. Live/work units located in townhouses and complying with the requirements of Section 419 of the International Building Code.2. Owner-occupied lodging houses with five or fewer guestrooms.3. A care facility with five or fewer persons receiving custodial care within a dwelling unit.4. A care facility with five or fewer persons receiving medical care within a dwelling unit.5. A care facility for five or fewer persons receiving care that are within a single-family dwelling.


R104.11 (2018)Alternative Materials, Design, and Methods of Construction and Equipment.Added new last sentence:Where the alternative material, design or method of construction is not approved, the building official shall respond in writing, stating the reasons the alternative was not approved.



Definitions - R202 (2018)

ACCESSORY STRUCTURE. A structure not greater than 3,000 square feet in floor area, and not more than two stories in height, the use of which thatis customarily accessory to and incidental to that of dwelling(s) and which that is located on the same lot.



ADDITION. An extension or increase in floor area, number of stories or height of a building or structure.

Definitions - R202 (2018)ACCESS (TO) That which enables a device, an appliance or equipment to be reached by ready access or by a means that first requires the removal or movement of a panel, door or similar obstruction.



ATTIC. The unfinished space between the ceilingassembly and the roof assembly

ATTIC, HABITABLE. A finished or unfinished habitable space within an attic


Definitions - R202 (2018)ACCESS (TO) That which enables a device, an appliance or equipment to be reached by ready access or by a means that first requires the removal or movement of a panel, door or similar obstruction.



CARBON MONOXIDE ALARM. A single- or multiple-station alarm intended to detect carbon monoxide gas and alert occupants by a distinct audible signal. It incorporates a sensor, control components and an alarm notification appliance in a single unit.



CARBON MONOXIDE DETECTOR.A device with an integral sensor to detect carbon monoxide gas and transmit an alarm signal to a connected alarm control unit.



CHANGE OF OCCUPANCY. A change in the use of a building or portion of a building that involves a change in the application of the requirements of this code.



CRAWL SPACE An underfloor space that is not a basement



LOCKING-TYPE TAMPER-RESISTANT CAP.A cap designed to be unlocked by a specially designed tool or key to prevent removal of the cap by means of hand-loosening or by commonly available tool



READY ACCESS (TO). That which enables a device, appliance or equipment to be directly reached, without requiring the removal or movement of any panel, door or similar obstruction.



Definitions - R202Townhouse

A single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof and with open space on at least two sides.


Townhouse Definition Originally based on the Boston Row House

Plan View


Townhouse Definition

Modified to permit “groups”

50% ???


VAPOR DIFFUSION PORTA passageway for conveying water vapor from an unvented attic to the outside atmosphere

Applies to new unvented roof assemblies in climate zones 1, 2 and 3


Section R105.2 Work exempt from permit is amended to read:

1. One story detached accessory structure used as tool and storage sheds, playhouses and similar uses, provided the floor area does not exceed 120square feet (11.5 m2) and wall height does not exceed 11’4” total height from finished floor to top of plate. 2. Fences not over 6’ (2134 mm)


11’ 4”Max


BUILDING PLANNING CHAPTER 3


Construction SystemsR301.1.1

Wood: Platform Frame Balloon Frame

Concrete or Masonry: Balloon Frame

Other systems: Designed per

accepted engineering practices


Design Criteria - R301.1 Support all loads Provide a

complete load path to the foundation

If limits of 301 are exceeded, design per accepted engineering practices


Design Criteria - Table R301.2(1) 2018

Ground Snow Load – Case Study Area view the Routt County Regional Building Department website for Ground Snow values for your specific site. https://routtgis.maps.arcgis.com/apps/webappviewer/index.html?id=df84ded7ab1b4de39a9f68dd7d05a3a0


Table R301.2(1) CLIMATIC AND GEOGRAPHIC DESIGN CRITERIA, is completed as follows

Wind Speed – 115 MPH (ultimate design wind speed) Topographic Effects – No Seismic Design Category – C: When approved by the

Structural Engineer Class B can be used when a soils report or historical data supports a class B designation.

Subject to Damage by Weathering – Severe Subject to Damage by Frost line Depth – 48 inches

(1220mm) Subject to Damage by Termite – None to slight Subject to Damage by Decay – None to slight




Winter Design: Outdoor Winter Design Dry-Bulb Temperature -15ºF (-26ºC) Indoor Winter Design Dry-Bulb Temperature: 70° F (21° C) Coincident Wet Bulb: 56°F (13° C) Heating temperature Difference: 85° F (29° C)



Summer Design: Outdoor Summer Design Dry-Bulb Temperature: 85° F (29°C) Indoor Summer Design Dry-Bulb Temperature: 75° F (24° C) Design Grains: Varies based on weather data Range: -35 to -55 Cooling Temperature Difference: 10° F (-12° C)



Altitude Correction: Varies 7,000’ 0.77 8,000’ 0.75 9,000’ 0.72 10,000’ 0.69 12,000’ 0.63 Latitude : 40° North



Ice Shield Underlayment Required – Yes Flood Hazards – FIRM, February 4, 2005 Air Freezing Index – Steamboat 2239 Mean Annual Temperature – 40-45ºF

(4.5-7.2ºC) Ground Snow Load Values are Governed

by Routt County Regional Building Department based on geographic location. Please visit our home page and click on Ground Snow Load Values for site-specific information.


R301.2.1.1 - Wind limitations and wind design required In regions where wind design is

required in accordance with Figure R301.2(4)B or where the basic wind speed shown on Figure R301.2(4)A equals or exceeds 110 miles per hour, the design of buildings for wind loads shall be in accordance with one or more of the following methods: 1. AF&PA Wood Frame Construction

Manual (WFCM); or 2. ICC Standard for Residential

Construction in High-Wind Regions (ICC 600); or

3. ASCE Minimum Design Loads for Buildings and Other Structures (ASCE 7); or

4. AISI Standard for Cold-Formed Steel Framing—Prescriptive Method For One-and Two-Family Dwellings (AISI S230); or

5. International Building Code.


R301.2.1.1.1Sunrooms. Sunrooms shall comply with AAMA/NPEA/NSA 2100.

Has five different categoriesDesigner to specify categoryAdding reference to standard prescriptive construction is easier based on the category


R302Fire Resistant Construction

Moves everything fire-resistance related to R302 Exterior Walls Townhouse Separation Two-Family Separation Penetrations Garage to Dwelling Under Stairs Foam Plastics Interior Finishes Fireblocking Draftstopping Insulation


R302.1Exterior Walls

Construction, projections, openings and penetrations of exterior walls of dwellings and accessory buildings shall comply with Table R302.1(1); or dwellings equipped throughout with an automatic sprinkler system installed in accordance with Section P2904 shall comply with Table R302.1(2).


Table R302.1(1) new footnotes (2018)


1 hour—tested in accordance with ASTM E119, UL 263 or Section 703.3 of the International Building Code with exposure from both sides



1 hour on the underside, or heavy timber, or fire-retardant-treated wood a, b

Table R302.1 (1) footnote: a


Table R302.1 (1) footnote: b


Gable vent not allowed

Table R302.1(2)Footnote: a

For residential subdivisions where all dwellings are equipped throughout with an automatic sprinkler systems installed in accordance with Section P2904, the fire separation distance for nonrated exterior walls and rated projections shall be permitted to be reduced to 0 feet, and unlimited unprotected openings and penetrations shall be permitted, where the adjoining lot provides an open setback yard that is 6 feet or more in width on the opposite side of the property line.


6 ft.

R302.2.2 Common Walls(2018)

Walls separating townhouse units shall be constructed in accordance with Section R302.2.1 or R302.2.2.


R302.2.1 Double walls (2018)

Each townhouse shall be separated by two 1-hour fire-resistance-rated wall assembliestested in accordance with ASTM E119, UL 263 or Section703.3 of the International Building Code.


Structural IndependenceR302.2.4 (2015)

Each townhouse shall be structurally independent

Exceptions: foundations roof & wall sheathing may

fasten to common wall nonstructural wall coverings flashing Townhouses separated by a

common wall as provided in Section R302.2.2, Item 1 or 2.


R302.4.2 Membrane penetrations (2018)

New exception:4. Ceiling membrane penetrations by listed luminaires or by luminaires protected with listed materials that have been tested for use in fire resistance-rated assemblies and are installed in accordance with the instructions included in the listing.


R302.7 Under-stair protection (2018)

Enclosed space under stairs that is accessed by a door or access panel shall have walls, under-stair surface and any soffits protected on the enclosed side with 1/2-inch gypsum board


Flame spread index and smoke-developed indexfor insulation R302.10.1 Insulation (2018)

Insulating materials installed within floor-ceiling assemblies, roof-ceiling assemblies, wall assemblies, crawl spaces and attics shall comply with the requirements of this section. They shall exhibit a flame spread index not to exceed 25 and a smoke-developed index not to exceed 450 where tested in accordance with ASTM E84 or UL 723. Insulating materials, where tested in accordance with the requirements of this section, shall include facings, where used, such as vapor retarders, vapor permeable membranes and similar coverings.


R308.4.2 Glazing adjacent to doors

2. Where the glazing is on a wall perpendicular to the plane of the door in a closed position and within 24 inches of the hinge side of an in-swinging door.


Yes

NoNo

No

R308.4.2 Glazing adjacent to doors (2015/2018)

2. Where the glazing is on a wall is less than 180° from the plane of the door in a closed position and within 24 inches of the hinge side of an in-swinging door.


Yes

NoNo

No

Less than 180°


Hazardous LocationsR308.4.3

Fixed or operable panel > 9 square feet < 18 inches above floor top edge > 36 inches above

floor walking surface within 36

inches Railings Enclosing pools, hot tubs, spas

R308.4.5 – Glazing and Wet Surfaces

Glazing in walls, enclosures, or fences containing OR FACING:

Bathtubs Showers Whirlpools, saunas,

steam rooms, indoor and outdoor pools

Shall be safety glazing is less than 60” AFF

57© 2020 Colorado Code Consulting, LLC

R308.4.5 – Glazing and Wet Surfaces

Exception: Glazing that is more

than 60” measured horizontally and in a straight line from the water’s edge of a bathtub, hot tub, spa, whirlpool, or swimming pool or from the edge of a shower, sauna or steam room.

60”


R310.3Emergency Escape/Rescue Doors (2018)

Where a door is provided as the required emergency escape and rescue opening, it shall be permitted to be a side-hinged door or a slider

Where the opening is below the adjacent ground elevationgrade, it shall be provided with a bulkhead enclosure an area well.


R310.3.1 Minimum door opening size

The minimum net clear height opening for any door that serves as an emergency and escape rescue opening shall be in accordance with Section R310.2.1. (Egress openings)


R310.3.2 Bulkhead Enclosures Area wells (2018)

Area wells shall have a width of not less than 36 inches. The area well shall be sized to allow the emergency escape and rescue door to be fully opened


R310.3.2.1 Ladders and steps (2018)

Required if area well greater than 44” deepNeed not comply with R311.7 or R311.8

(Stairways)Ladders or rungs

Inside ≥ 12”Project ≥ 3”Rung spacing ≤ 18”


R310.4 Bars, grilles, covers and screens

Bars, grilles, covers, screens or similar devices are permitted to be placed over emergency escape and rescue openings, bulkhead enclosures area wells, or window wells that serve such openings, provided: Minimum net clear opening size

complies with Sections R310.1.1 to R310.1.3,

Such devices are releasable or removable from the inside without the use of a key, tool, special knowledge or force greater than that which is required for normal operation of the escape and rescue opening.


R311.7.4 (2018)


Section R311.7.8 Handrails. amended to read as follows adding exception:

Exception: A Handrail shall not be required if you have four total risers and the total vertical drop from top of treads, landing, or floor level is not greater than 30 inches measured vertically to the floor or grade below at any point within 36 inches horizontally to the edge of the open sides.


≤30”36”

Section R313 Automatic fire sprinkler systems, is hereby delete


R313.1Automatic fire sprinklers

Required in all new one- and two-family dwellings and townhouses

Must be designed in accordance with P2904 or NFPA 13D


R314.4 Interconnection (2018)Removed the exception:Interconnection of smoke alarms in existing areas shall not be required where alterations or repairs do not result in removal of interior wall or ceiling finishes exposing the structure, unless there is an attic, crawl space or basement available that could provide access for interconnection without the removal of interior finishes


Carbon Monoxcide Alarms R315.5 Interconnectivity (2018)

When more than one requiredShall be interconnected (same as Smoke Detectors)

Exception:Interconnection of carbon monoxcide alarms in existing areas shall not be required where alterations or repairs do not result in removal of interior wall or ceiling finishes exposing the structure, unless there is an attic, crawl space or basement available that could provide access for interconnection without the removal of interior finishes.



316 – Foam Plastics Flame spread

≤ 75 Smoke

developed index ≤ 450

Typically ½” gypsum board thermal barrier required.

316 – Foam Plastics In crawl spaces

and attics Entry made only

for repairs or maintenance

Ignition barrier 3/8” Gypsum, ¼” hardboard


316 – Foam Plastics

Thermal or ignition barrier not required rims or box sills

Not more than 3 ¼” thick

0.5 to 2.0 pounds density

Flame and smoke of 25-450



Flood Resistant ConstructionR322

Buildings and structures constructed in whole or in part in flood hazard areas (including A or V Zones) as established in Table R301.2(1) shall be designed and constructed in accordance with the provisions contained in this section.

Buildings and structures located in whole or in part in identified floodways shall be designed and constructed in accordance with ASCE 24.


R324.4 Rooftop-mounted photovoltaic systems

Rooftop-mounted photovoltaic panel systems installed on or above the roof covering shall be designed and installed in accordance with Section R907 this section.


R324.4.1 Roof Live Load (2018)Portions of roof structures not covered with photovoltaic panel systems shall be designed for dead loads and roof loads in accordance with Sections R301.4 and R301.6. Portions of roof structures covered with photovoltaic panel systems shall be designed for the following load cases:1. Dead load (including photovoltaic panel weight) plus snow load in accordance with Table R301.2(1).2.Dead load (excluding photovoltaic panel weight) plus roof live load or snow load, whichever is greater, in accordance with Section R301.6.

R324.6 Roof access and pathways(2018)

Shall be providedExceptions:1. Detached non-habitable structures, carports, detached garages2. AHJ determined no roof top operations3. Roof pitch 2/12 and less


R324.6.1 Pathways (2018)Two pathways, on separate roof planes from lowest roof edge to ridge and not less than 36 inches wideOne pathway shall be provided on the street or driveway side of the roofEach roof plane with a photovoltaic array:Pathway not less than 36 inches wide shall be provided from the lowest roof edge to ridge on the same roof plane as the photovoltaic array, on an adjacent roof plane, or straddling the same and adjacent roof planes.Pathways shall be over areas capable of supporting fire fighters accessing the roof. Pathways shall be located in areas with minimal obstructions such as vent pipes, conduit, or mechanical equipment


R324.6.2.2 Emergency escape and rescue opening (2018)Panels and modules installed on dwellings shall not be placed on the portion of a roof that is below an emergency escape and rescue opening. A pathway not less than 36 inches wide shall be provided to the emergency escape and rescue opening


R325.6 Habitable attic (2018)A habitable attic shall not be considered a story where complying with all of the following requirements:1. The occupiable floor area is not less than 70 square feet, in accordance with Section R3042. The occupiable floor area has a ceiling height in accordance with Section R3053. The occupiable space is enclosed by the roof assembly above, knee walls (if applicable) on the sides and the floor-ceiling assembly below4. The floor of the occupiable space shall not extend beyond the exterior walls of the floor below


Section R325.6 Item 3 is amended to read as follows

3. The occupiable attic space is enclosed by the roof assembly above intersecting and connecting directly to the top of the floor-ceiling assembly on the story below with a maximum vertical height on the sides from the top of finished floor-ceiling assembly to top of finished roof deck to be no more than 20” tall.


R327 Stationary storage battery systems (2018)

Exceptions:Where approved, repurposed unlisted battery systems from electric vehicles are allowed to be installed outdoors or in detached sheds located not less than 5 feet from exterior walls, property lines and public ways



Exceptions:Battery systems that are an integral part of an electric vehicle are allowed provided that the installation complies with Section 625.48 of NFPA 70



Exceptions:Battery systems less than 1 kWh


R327.3 Installation (2018)Stationary storage battery systems shall be installed in accordance with the manufacturer’s instructions and their listing, if applicable, and shall not be installed within the habitable space of a dwelling unit


R327.4 Electrical installation (2018)

Storage systems in accordance with NFPA 70Inverters shall be listed and labeled in accordance with UL 1741 or provided as part of the UL 9540 listing Systems connected to the utility grid shall use inverters listed for utility interaction.


R327.5 Ventilation (2018)

Indoor installations of stationary storage battery systems that include batteries that produce hydrogen or other flammable gases during charging shall be provided with ventilation in accordance with Section M1307.4.



FOUNDATIONS – Chapter 4


R408.3 Unvented crawl space

New option in 2018:2.4. Dehumidification sized to provide 70 pints of moisture removal per day for every1,000 square feet of crawl space floor area

Section R408.3 Unvented Crawl Space amended to read as follows adding item 2.5

2.5 Ventilation Equipment installed under 2.1 and 2.2 may operate intermittently for a minimum of 1-hour for every 24-hour period, if exhaust only system is installed in accordance with 2.1, or when a dedicated HRV/ERV fan is installed to serve only the crawl space area under section 2.2.


2.1. Continuously operated mechanical exhaust ventilation at a rate equal to 1 cubic foot per minute (0.47 L/s) for each 50 square feet (4.7 m2) of crawl space floor area, including an air pathway to the common area (such as a duct or transfer grille), and perimeter walls insulated in accordance with Section N1102.2.11 of this code.

2.2. Conditioned air supply sized to deliver at a rate equal to 1 cubic foot per minute (0.47 L/s) for each 50 square feet (4.7 m2) of under-floor area, including a return air pathway to the common area (such as a duct or transfer grille), and perimeter walls insulated in accordance with Section N1102.2.11 of this code.



FLOORS – Chapter 5


Chapter 5Floors

Wood Floor Framing Pressure

Preservative Treated-Wood Floors

Steel Floor Framing Concrete

R507 Exterior Decks (2018)R507.1 DecksWood-framed decks shall be in accordance with this section. For decks using materials and conditions not prescribed in this section, refer to Section R301


R507.2.1 Wood materials (2018)Wood materials shall be No. 2 grade or better lumber, preservative-treated in accordance with Section R317, or approved, naturally durable lumber, and termite protected where required All preservative-treated wood products in contact with the ground shall be labeled for such usage


R507.2.3 Fasteners and connectors (2018 new table)

TABLE R507.2.3 FASTENER AND CONNECTOR SPECIFICATIONS FOR DECKS a,b


Table R507.2.3 (2018 footnotes)

a. Equivalent materials, coatings and finishes shall be permitted.b. Fasteners and connectors exposed to salt water or located within 300 feet of a salt water shoreline shall be stainless steel.c. Holes for bolts shall be drilled a minimum 1/32 inch and a maximum 1/16 inch larger than the bolt.d. Lag screws 1/2 inch and larger shall be predrilled to avoid wood splitting per the National Design Specification (NDS) for Wood Construction.e. Stainless-steel-driven fasteners shall be in accordance with ASTM F1667.


R507.3 Footings (2018)Decks shall be supported on concrete footings or other approved structural systemsDeck footings shall be sized to carry the imposed loads from the deck structure to the ground as shown in Figure R507.3. The footing depth shall be in accordance with Section R403.1.4.


R507.3.2 Footings (2018)

Deck footings shall extend below the frost line specified in Table R301.2(1) in accordance with Section R403.1.4.1.Exceptions:1.Free-standing decks that meet all of the following criteria:

1.1. The joists bear directly on precast concrete pier blocks at grade without support by beams or posts.1.2. The area of the deck does not exceed 200 square feet1.3. The walking surface is not more than 20 inches above grade at any point within 36 inches measured horizontally from the edge.

2. Free-standing decks need not be provided with footings that extend below the frost line.


Figure R507.3 (2018)


R507.3.1 Minimum size (2018)The minimum size of concrete footings shall be in accordance with Table R507.3.1, based on the tributary area and allowable soil-bearing pressure in accordance with Table R401.4.1.


R507.2.1 Ledger Details (2018 R507.9.11)

Deck ledgers installed in accordance with Section R507.2 shall be a minimum 2-inch by 8-inch nominal, pressure-preservative-treated southern pine, incised pressure-preservative-treated Hem-fir, or approved, naturally durable, No. 2 grade or bet-ter lumber. Deck ledgers installed in accordance with Section R507.2 Shall not support concentrated loads from beams or girders. Deck ledgers shall not be supported on stone or masonry veneer © 2018 Colorado Code Consulting, LLC 103

R507.2.2 Band joist details(2018 R507.9.1.2)

Band joists attached by a ledger in accordance with Section R507.2 shall be a minimum 2-inch-nominal, solid-sawn, spruce-pine-fir lumber or a minimum 1-inch by 9 1/2-inch dimensional, Douglas fir or better, laminated veneer lumber. Band joists attached by a ledger in accordance with Section R507.2 shall be fully supported by a wall or sill plate belowBand joists shall bear fully on the primary structure capable of supporting all required loads.


R507.2.3 Ledger to band joist fastener details(2018 R507.9.1.3) No content change

Fasteners used in deck ledger connections in accordance with Table R507.2 shall be hot-dipped galvanized or stainless steel and shall be installed in accordance with Table R507.2.1 and Figures R507.2.1(1) and R507.2.1(2)


TABLE R507.2 (R507.9.1.3(1) 2018)No change to table


R507.9.1.3(1) 2018 No change



R507.9.1.3(2) 2018 No change

R507.2.4 Deck lateral load connection (R507.9.2 2018)

The lateral load connection required by Section R507.1 shall be permitted to be in accordance with Figure R507.2.3(1) or R507.2.3(2). Lateral loads shall be transferred to the ground or to a structure capable of transmitting them to the ground.Where the lateral load connection is provided in accordance with Figure R507.2.3(1) Figure R507.9.2(1), hold-down tension devices shall be installed in not less than two locations per deck, within 24 inches of each end of the deck. Each device shall have an allowable stress design capacity of not less than 1,500 pounds. Where the lateral load connections are provided in accordance with Figure R507.2.3(2) R507.9.2(2), the hold-down tension devices shall be installed in not less than four locations per deck, and each device shall have an allowable stress design capacity of not less than 750 pounds


FIGURE 507.9.2(1) (2018 No change)


111

FIGURE 507.9.2(2) (2018 No change)


R507.4 Decking (R507.7 2018)Maximum allowable spacing for joists supporting decking shall be in accordance with Table R507.7. Wood decking shall be attached to each supporting member with not less than (2) 8d threaded nails or (2) No. 8 wood screws. Other approved decking or fastener systems shall be installed in accordance with the manufacturer’s installation requirements.


2018 minor changes to table

R507.5 Deck joists (R507.6 2018)

Maximum allowable spans for wood deck joists, as shown in Figure R507.6, shall be in accordance with Table R507.6. Deck joists shall be permitted to cantilever not greater than one-fourth of the actual, adjacent joist span.


New for 2018


R507.5.1 Lateral Restraint at Supports (R507.6.2 2018)

Joist ends and bearing locations shall be provided with lateral restraint to prevent rotation. Where lateral restraint is provided by joist hangers or blocking between joists, their depth shall equal not less than 60 percent of the joist depth. Where lateral restraint is provided by rim joists, they shall be secured to the end of each joist with not less than (3) 10d (3 inch by 0.128 inch) nails or (3) No. 10 by 3 inch long wood screws.


No content changes for 2018

R507.5.1 Deck beam bearing (2018)The ends of beams shall have not less than 1 1/2 inches of bearing on wood or metal and not less than 3 inches of bearing on concrete or masonry for the entire width of the beam.Where multiple-span beams bear on intermediate posts, each ply must have full bearing on the post in accordance with Figures R507.5.1(1) and R507.5.1(2)


New for 2018


R507.6 Deck Beams (R507.5 2018)Maximum allowable spans for wood deck beams, as shown in Figure R507.5, shall be in accordance with Table R507.5.Beam plies shall be fastened with two rows of 10d (3 inch by 0.128 inch) nails minimum at 16 inches on center along each edge. Beams shall be permitted to cantilever at each end up to one-fourth of the actual beam span. Splices of multi-span beams shall be located at interior post locations. Deck beams of other materials shall be permitted where designed in accordance with accepted engineering practice


R507.7.1 Deck beam connection to supports (R507.5.2 2018)

Deck beams shall be attached to supports in a manner capable of transferring vertical loads and resisting horizontal displacement. Deck beam connections to wood posts shall bein accordance with Figures R507.5.1(1) and R507.5.1(2).Manufactured post-to-beam connectors shall be sized for the post and beam sizes. All bolts shall have washers under the head and nut.Exception: Where deck beams bear directly on footings in accordance with Section R507.8.1. © 2018 Colorado Code Consulting, LLC 122

R507.8 Deck posts (R507.4 2018)For single-level, wood-framed decks with beams sized in accordance with Table R507.5, deck post size shall be in accordance with Table R507.4


New table for 2018

R507.8.1 Deck post to deck footing (R507.4.1 2018)

Posts shall bear on footings in accordance with Section R403 and Figure R507.8.1. Posts shall be restrained to prevent lateral displacement at the bottom support. Such Where posts bear on concrete footings in accordance with Section R403 and Figure R507.4.1, lateral restraint shall be provided by manufactured connectors installed in accordance with Section R507 and the manufacturers’ instructions or a minimum post embedment of 12 inches in surrounding soils or concrete piers. Other footing systems shall be permitted

Exception: Where expansive, compressible, shifting or other questionable soils are present, surrounding soils shall not be relied on for lateral support



WALL CONSTRUCTIONCHAPTER 6


Chapter 6Wall Construction

Wood Wall Framing Steel Wall Framing Masonry Walls Insulated Concrete Foam Concrete Exterior Windows and

Glass Doors


Wood Wall FramingR602

Grade mark required End-joint lumber may

be used (grade stamp) Studs min. No. 3,

standard or stud grade bearing studs not

supporting floors & non bearing studs may be utility grade


R602.3.2 Top plate Double Top Plate Required

Overlapped at corners and intersections of bearing walls

End joints of plates offset 24“ Joints in plates not required to

occur over studs.

Single top plate Permitted if tied at joints with

3”X6” steel plate each side Bottom plate

Nominal 2” thick with width same as stud


Wood Wall FramingTable R602.3(5)


NotchingR602.6

Notching Exterior & bearing

cannot exceed 25% of stud width

Non-bearing up to 40% of stud

width

Drilling Max. 40% of stud Min. 5/8” from edge


Drilling/Notching of Top PlateR602.6.1

Top plate cut by more than 50 % Galvanized metal tie

Minimum 0.054 inch thick (16 gage)

11/2 inches wide Fastened to each plate

with not less than EIGHT 10d nails 1.5” long at each side or equivalent


Girder SpansTable R502.5

Exterior header for 7’6” openingsupporting roof/ceiling

R602.10 Wall Bracing

Buildings shall be braced in accordance with this section or, when applicable, Section R602.12. Where a building, or portion thereof, does not comply with one or more of the bracing requirements in this section, those portions shall be designed and constructed in accordance with Section R301.1.


Wall Bracing Overview Intermittent

bracing Continuous

sheathing Engineered

design


New user-friendly format…


R602.10 Wall Bracing

Sep. table for seismic



R612.1 Exterior windows and doors

Windows shall be installed and flashed in accordance with fenestration manufacturer’s installation instructions.


WALL COVERINGCHAPTER 7


InstallationR701.2

Products sensitive to adverse weather shall not be installed until adequate weather protection for the installation is provided.

Exterior sheathing shall be dry before applying exterior cover.


R702.4.2. Tile backing – Wet areas

Fiber-cement, fiber-mat reinforced cementitiousbacker units, glass mat gypsum backers or fiber-reinforced gypsum backers shall be used as backers for wall tile in tub and shower areas and wall panels in shower areas.

R702.7Vapor Retarders Class I or II vapor

retarders are required on the interior side of frame walls in Climate Zones 5, 6, 7, 8 and Marine 4.

Exceptions: 1. Basement walls. 2. Below grade portion of

any wall. 3. Construction where

moisture or its freezing will not damage the materials.


702.7.1Class III Vapor Retarders


R702.7.2Material Vapor Retarder Class

The vapor retarder class shall be based on the manufacturer’s certified testing or a tested assembly.

The following shall be deemed to meet the class specified: Class I: Sheet polyethylene,

unperforated aluminum foil. Class II: Kraft-faced fiberglass

batts. Class III: Latex or enamel

paint.



Exterior CoveringR703

The exterior wall envelope shall be designed and constructed in such a manner as to prevent the accumulation of water within the wall assembly by providing a water-resistive barrier behind the exterior veneer as required by Section R703.2.


R703.2Water-Resistive Barrier

#15 Asphalt Felt required everywhere!

Except: Detached accessory Per Table 703.4


R703.2 Table R703.4

requires a water resistive barrier under ALLexterior siding materials.


FlashingR703.8

Approved corrosion-resistive flashing shall be provided in the exterior wall envelope in such a manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components


FlashingR703.8

Required Exterior window & door

openings Intersection of masonry with

frame or stucco walls Uunder/ends of copings and

sills Projecting wood trim Porch, deck or stair

attachments Wall/roof intersections Built-in gutters


Chapter 8 Roof-Ceiling Construction


Roof DrainageR801.3

In areas where expansive or collapsible soils are known to exist, all dwellings shall have a controlled method of water disposal from roofs that will collect and discharge all roof drainage to the ground surface at least 5 feet from foundation walls or to an approved drainage system.


Rafter SpansTable R802.5 (1-8)


Alterations to trussesR802.10.4

Truss members shall not be cut, notched, drilled, spliced or otherwise altered in any way without the approval of a registered design professional.

Alterations resulting in the addition of load shall not be permitted without verification that the truss is capable of supporting such additional loading.

R802.11 – Roof Uplift Resistance

Trusses shall be attached to the supporting wall assemblies by connections capable of resisting uplift forces as specified on the truss design drawings.



However… “Uplift forces shall be

permitted as determined as specified by Table R802.11, if applicable, or as determined by accepted engineering practice”

This is a new table with 85-110 mph covered at Exposure B and C



Rafter Uplift Resistance

Individual rafters shall be attached per Table R802.11

…or as determined by accepted engineering practice.


R806 – Roof Ventilation 1:300 exception

changed: Requires Class I or

II vapor retarder in warm side of ceiling in Climate Zones 6, 7, and 8.

AND…


R806 – Roof Ventilation 40-50% of ventilation at

upper portion of attic. Upper ventilation no more

than 3’ below the ridge More than 3’ if wall or roof

framing will not permit the opening to be within the 3’

Remainder at eave or cornice.



R806.5 Conditioned attic assemblies

Unvented conditioned attic assemblies (spaces between the ceiling joists of top story and the roof rafters) are permitted under specific conditions.



1. Must be within the building thermal envelope.

2. No interior vapor barriers on ceiling side

3. Wood shingles/shakes – ¼ inch air between sheathing

4. Air-impermeable insulation on underside of roof deck (Climate Zones 5, 6, 7, and 8)

1. Or vapor retarder coating applied.


Either Items 5.1, 5.2 or 5.3 shall be met, depending on the air permeability of the insulation directly under the structural roof sheathing.


R806.5 Unvented attic and unvented enclosed rafter assemblies (2018)

https://buildingscience.com/documents/insights/bsi-088-venting-vaporLink to Building Science article explains in detail the unvented attic assemblies in climate zones 1, 2 and 3



Attic AccessR807

Combustible ceiling or roof construction

22”X30” opening hallway or readily accessible

location M1305.1.3 mechanical access

R807Attic Access

Access opening 30” any point

When access opening req’d 30” for 30sf

above ceiling framing



ROOF ASSEMBLIESCHAPTER 9


Roof ClassificationR902

Class A, B, C required less than 3’ to lot line designated by law

Brick, masonry, exposed concrete roof deck is considered Class A,


Weather ProtectionR903

Roof decks shall be covered with approved roof coverings secured to the building or structure in accordance with the provisions of this chapter.

Roof assemblies shall be designed and installed in accordance with this code and the approved manufacturer’s installation instructions such that the roof assembly shall serve to protect the building or structure.

R903.2.1 Locations (Flashing) Installed to divert

water away from where an eave of a roof intersects with a vertical sidewall



R903.2.2 Crickets and saddles

Cricket or saddle shall be installed on ridge side of any chimney or penetration more than 30 inches wide as measured perpendicular to the slope.


Roof DrainageR903.4

Unless roof drains over roof edge, roof drains and scuppers required Sized per IPC Overflow 2” above roof

drain inlet Scuppers 3 times roof

drain, 2” above inlet Overflow not allowed to

be connected to roof drain lines


Roof CoveringsR905

Asphalt Shingles Clay & concrete tiles Metal roof shingles Mineral-surfaced roll roofing Slate shingles Wood shingles/shakes Built-up roofs Modified Bitumen Single-ply roofing Sprayed foam roofing Liquid-applied coatings


CHIMNEYS & FIREPLACESCHAPTER 10


Masonry ChimneysR1001.1

Masonry fireplaces shall be constructed in accordance with this section and the applicable provisions of Chapters 3 and 4.


Factory-Built FireplacesR1004

Must be listed & labeled Hearth extension per

listing Unlisted decorative

shrouds not permitted

R1004.4 Unvented gas log heaters. Deleted

An unvented gas log heater shall not be installed in a factory-built fireplace unless the fireplace system has been specifically tested, listed and labeled for such use in accordance with UL 127.



Exterior Air SupplyR1006.1

Exterior air required for factory-built or masonry fireplaces unless room is mechanically ventilated so indoor pressure is neutral or positive Factory built fireplaces

follow manufacturers listing

Masonry fireplaces may use listed combustion air ducts installed per listing

181

Colorado Code Consulting, LLC4610 S Ulster, Suite 150Denver, CO 80237

Ph. 303-400-6564Fax 303-693-0630

[email protected]


2015-2018 international residential code

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