2018 IRC Significant Changes to Deck Provisions - Color Version · 2021. 1. 7. · AWPA M4...

2018 IRC Update 5/22/2019

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12018 IRC Significant Changes to Deck Provisions

2018 IRC SIGNIFICANT CHANGES TO DECK PROVISIONSBCD310

Sandra Hyde, P.E.Senior Staff EngineerInternational Code Council Disclaimer: This presentation was developed by a

third party and is not funded by the AmericanWood Council or the Softwood Lumber Board.


Participants may download the presentation here: http://www.awc.org/education/resources

The American Wood Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider # 50111237.

Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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COURSE DESCRIPTIONThis webinar introduces basic design and construction methods for single-story residential wood decks focusing on the significant changes for the 2018 IRC. The vertical and lateral load paths of conventional residential decks are addressed in the 2018 International Residential Code.

Specific design guidance includes convenient span tables for joists and beams and charts of post sizing limitations and connection methods. Figures for multiple lateral connections make connection to an existing dwelling simpler and require less removal of existing materials.

Photo courtesy of California Redwood Association


LEARNING OBJECTIVESUpon completion, participants will be better able to:

Identify vertical and lateral load paths of conventional residential decks

Load Paths

Determine appropriate beams and joist span lengths using IRC provisions

Beams and Joist Spans

Identify minimum footing size and materials per 2018 IBC

Footings

Determine lateral connection options for the deck to existing dwelling based on IRC requirements

Lateral Connections

1 2

3 4

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CODES AND STANDARDS


GENERAL REQUIREMENTSExisting Buildings – R102.7

Legal occupancy of any structure existing on the date of adoption of a code is permitted to continue without change.

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GENERAL REQUIREMENTSExisting Buildings – R102.7.1

Additions, alterations or repairs to a structure shall conform to requirements for a new structure.


GENERAL REQUIREMENTSManufacturer’s Installation Instructions – R106.1.2

Manufacturer’s installation instructions shall be at the jobsite during inspection.

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GENERAL REQUIREMENTSPermits – R105.2

Item 10 – A permit not required for a deck that meets ALL these requirements:

• Not exceeding 200 ft2 in area

• Not more than 30 inches above grade at any point

• Not attached to a dwelling• Not serving the egress

door

1 02018 IRC Significant Changes to Deck Provisions

GENERAL REQUIREMENTSUsed Materials – R104.9.1

Used materials, equipment and devices shall not be reused unless approved

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GENERAL REQUIREMENTSAlternative Materials and Methods – R104.11

An alternative material, design or method of construction shall be approved if the proposed design is satisfactory and complies with the intent of the code.


EVALUATION REPORTS

ESR-1137 ITW Red Head EPCON G5 Adhesive Anchoring System

ESR-2138 Simpson Strong-Tie® Powder-Actuated Fasteners, Threaded Studs and Assembles

ESR-1369 GEODECK™ Composite Decking and Guardrail Systems

ESR-146 Master Mark Rhino Composite Decking

ESR-3269 GRSTM Glass Balustrade Guard System for Monolithic Tempered Glass Applications

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EVALUATION REPORTS

1

2

3

4

5

6

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Load Paths

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LOAD PATHVertical (Gravity) Load Path

1. Wall2. Ledger3. Decking4. Joist5. Beam

7. Foundation8. Ground

6. PostLoad

Load

Load


LOAD PATHLateral (Sideways) Load Path

1. Wall2. Ledger3. Decking4. Joist5. Beam

7. Foundation8. Ground

6. Post

Load

Load

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LATERAL FORCES

Wind

Force =Pressure x Area

Force =Mass x Acceleration

Seismic


Deck Requirements

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SIGNIFICANT CHANGE ICONS

Addition Deletion Modification Clarification


R507 DECKSReorganization of section

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R507.1• Wood-framed decks

use R507.

• For other decks refer to Section R301 for engineered design.


DECK DESIGNDeck design and construction – R507Wood-framed decks follow the requirements of this section or be engineered for specific materials and conditions

Decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads.

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DECK DESIGNDeck design and construction – R507

Where positive connection to the primary building structure cannot be verified during inspection, decks shall be self-supporting.

© Irina Mos/Shutterstock.com.


DECK DESIGNDeck design and construction – R507Decks with cantilevered framing members connected to exterior walls or other framing members shall be designed and constructed to resist uplift from loads acting on the cantilevered portion of the deck.

© Irina Mos/Shutterstock.com.

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DECK DESIGNAlternative provisions – R301.1.1Other standards can be used to design a deck. Although not specifically referenced in the IRC, DCA 6-2015, the deck design guideline from the American Wood Council can be used to design a deck.

Additional documents may be available in some regions.


DECK DESIGNEngineered design – R301.1.3

A deck may be designed by an engineer or architect. In that case, the requirements of Section R507 need not be followed.

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DECK DESIGN

• Ground snow

• Wind speed

• Seismic design category

Design criteria – R301.2

• Weathering of concrete• Frost line depth• Termite prevalence


DECK DESIGNLive loads – R301.5

Use Live Load

Balconies (exterior) and deckse 40

Fire escapes 40

Guards and handrailsd 200h

Guard in-fill componentsf 50h

Stairs 40c

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R507.2, R507.3 DECK MATERIALS

• Fasteners• Fastener

connections• Flashing • Alternative

materials


SELECTING DECK MATERIALSSawn Lumber – R502.1.1Sawn lumber shall be identified by a grade mark of an accredited lumber grading or inspection agency.

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SELECTING DECK MATERIALSNaturally durable solid-sawn lumber

• 90% or more of lumber stud, post or beam is heartwood

• Redwood, cedar, black locust or black walnut lumber (decay resistant)


SELECTING DECK MATERIALSPreservative-treated lumberProtection of lumber from decay is provided by use of naturally durable wood or wood that is preservative-treated using AWPA U1.

Photo Courtesy of BB&S Treated Lumber of New England

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PRESERVATIVE-TREATED LUMBERQuality mark – R317.2

Lumber and plywood required to be pressure-preservative treated shall bear the quality mark of an approved inspection agency.


PRESERVATIVE-TREATED LUMBERRequired information – R317.2.1

1. Identification of the treating plant.

2. Type of preservative.

3. The minimum preservative retention.

4. End use for which the product was treated.

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PRESERVATIVE-TREATED LUMBERRequired information – R317.2.1

5. Standard to which the product was treated.

6. Identity of the approved inspection agency.

7. The designation “Dry,” if applicable.


PRESERVATIVE-TREATED LUMBERLocation required: ground contact – R317.1.2Use approved pressure-preservative-treated wood suitable for ground contact use for wood

• in contact with the ground

• embedded in concrete in ground exposed to the weather

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PRESERVATIVE-TREATED LUMBERWood Columns – R317.1.4Deck posts supported by concrete piers less than 6 inches above exposed earth require decay resistant or pressure treated lumber.


PRESERVATIVE-TREATED LUMBERField Treatment – R317.1.1Field-cut ends, notches and drilled holes of preservative-treated wood shall be treated in the field using the AWPA M4 standard.

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PORCHES AND DECKSLocation required: geographical areas – R317.1.3

When lumber is exposed to the weather without roof, eave or overhang naturally durable or pressure-preservative treated wood shall be used for the structural supports of balconies and porches.


SELECTING DECK MATERIALSEngineered lumber

Layered wood products including:• Glulam• Laminated veneer lumber (LVL)• Parallel strand lumber (PSL) • Laminated strand lumber (LSL) • Oriented strand lumber (OSL) • Plywood• I-joists

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SELECTING DECK MATERIALSFasteners for preservative-treated wood – R317.3.1

Fasteners, including nuts and washers, shall be one of the following: • Hot-dipped, zinc-coated

galvanized steel (min. ASTM A 653 type G185)

• Stainless steel • Silicon bronze • Copper


R507.3 DECK FOOTINGS

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Load bearing value of soils1500 psf

Live or ground

snow load

Tributary Area

(sq ft)

Side of square

footing (in)

Diameter of round

footing (in)Thickness

(in)

40

40 14 16 660 17 19 680 20 22 7

100 22 25 8120 24 27 9



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R507.4 DECK POSTS

Deck post sizeMaximum

height (ft–in)

4 x 4 6-9

4 x 6 8

6 x 6 14

8 x 8 14

Note: a 4x4 post with 1 or 2 beam plies may be up to 8 ft tall (Footnote c)

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R507.4 DECK POSTS

Soils that do not provide lateral support:• Expansive• Compressible• Shifting • Questionable


R507.5 DECK BEAMS

5½ in.

2 in.

Allows SP single-ply beams Cantilever ¼ span (center-to-center)

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DECK BEAMS


DECK BEAMSDrilling and notching – R502.8

• Structural solid sawn members shall not be cut, bored or notched in excess of limitations in the Figure 502.8.

• Engineered lumber may not be cut, bored or notched unless permitted by the manufacturer.

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TABLE R507.5 DECK BEAM SPAN LENGTH


R507.6 DECK JOISTS• Span length

• Cantilever length

• ¼ actual span length (measured from center of support to center of support)

OR

• Tabular cantilever value, whichever is smaller

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TABLE R507.6 DECK JOIST SPAN


DECK JOISTS• Now includes

freestanding decks

• Lateral support by blocking at a cantilever

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DECK JOIST BEARINGJoist bearing:

• 1-1/2 in. min. on wood or metal

• Joist framing supported by approved joist hangers at side of beam

• Joists bearing on a beam attached to resist lateral movement


DECK JOIST LATERAL RESTRAINTJoist ends and bearing locations shall be provided with lateral restraint to prevent rotation.

• Joist hangers or blocking - depth > 60 percent of the joist depth

• Rim joists - nailed with (3) 10d (3-inch x 0.128-inch) nails or (3) #10 x 3-inch long wood screws

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DECK JOISTSFraming of openings – R502.10

• Openings in floor framing (for stairs) are framed with a header and trimmer joists.

• Double joists if their span is greater than 4 feet.


R507.7 DECKING

• Max joist spacing

• Attachment = min. 2-8d threaded nails or 2-#8 wood screws

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COMPOSITE MATERIALS

Plastic composite = a generic designation referring to wood-plastic composites and plastic lumber.


PLASTIC COMPOSITE

R311.7.8.4, 312.1.4, 317.4Requirements from ASTM D 7032 include minimum standards for:• Flame spread < 200• Decay resistance• Termite resistance• Labeling – load and allowable span

DECK BOARDS, STAIR TREADS, GUARDS, OR HANDRAILS

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FASTENERS AND CONNECTORS

Fasteners in preservative-treated and fire-retardant-treated wood shall meet the requirements of ASTM A153 (min. zinc coating weight) or ASTM F 1667 for stainless steel.


DECKINGMaximum joist spacing for decking – Table R507.7

Decking Material Type and

Nominal Size

Maximum On-center Joist SpacingDecking perpendicular

to joistDecking diagonal

to joist1¼-inch-thick wood 16 inches 12 inches

2-inch-thick wood 24 inches 16 inches

Plastic compositeIn accordance with

Section R507.2In accordance with

Section R507.2

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R507.8-R507.9

• Section divided into vertical and lateral support of the deck• Ledger details• Band joist details• Lateral connection• Alternates

Decking, Vertical and Lateral Supports


LEDGERMinimum 2x8 nominal:

• Pressure-preservative treated southern pine

• Incised pressure-preservative-treated hem-fir

• No. 2 or better naturally durable lumber

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LEDGER• May not support concentrated

loads from beams or girders.

• May not be supported on stone or masonry veneer.


LEDGERBand joist details

Minimum band joist =

• Minimum 2" nominal solid-sawn, SPF lumber

• Minimum 1" x 9.5" Douglas fir LVL

• Must be fully supported from below.

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LEDGERBand joist details

Solid board must exist, in the case of open web joists, the ribbon strip of OSB is not sufficient connection.


LEDGERLedger at dwelling cornersA built-up beam used to carry joists cannot be attached to the ledger or band joist.

• Option “A” shows the beam extending into the existing structure and resting on the foundation below, while

• Option “B” depicts an independent support provided underneath the beam, such as a post or pier.

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LEDGERDecks at dwelling cantilevers

At the cantilevered face of the dwelling, a dropped beam can take the load of the deck joists.


LEDGERFasteners for ledger attachment

• Fasteners shall be hot-dipped galvanized or stainless steel

• Installed following Tables R507.9.1.3(1) and (2) and Figures R507.9.1.3(1) and (2)

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LEDGERDeck lateral load connection

• Lateral load connection provided by hold-downs, angles or any other approved method

• Total resistance should be 3000 lbs (tension), in this case 2 – 1500 lbhold-downs

Is this required?


LEDGER

New attachment method in the 2015/18 IRC

Option 2

Deck attachment for lateral loads – Figure R507.2.3(2)

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R312.1 GUARDS


R312.1 GUARDS

Errata in book

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FOUNDATIONMinimum depth is 12 inches below undisturbed soil depth.


FOUNDATIONRetaining Walls – R404.4

When a deck is on top of a retaining wall (supports load) – max. height is 24 inches without engineered design.

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FOUNDATIONMinimum footing size – R403.1

SDC D0, D1, D2• Minimum footing size is

12 inches by 6 inches.

• Minimum reinforcement per Figure R403.1.3.


FOUNDATIONHow much of the concrete in the footing is really needed?

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FOUNDATION

Concrete pier and isolated footing

Potential issues?

Post (min 6x6)

Concrete Pier

Concrete Footing

< 6 in.

6 in. min.

Concentrated Load

45˚ bearing angle

Soil Resistive ForceBearing Area

Grade


FOUNDATIONPost on undersized concrete footing

• Footing depth must be greater than the length of footing beyond the edge of the post

Concrete Footing 6 in.

45˚ bearing angle

Soil Resistive Force

Design Bearing Area

Post (min 6x6)

Concentrated Load

> 6 in.

Effective Bearing Area

Failure

Grade

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FOUNDATION

Post on concrete footing

Potential issues?

Concrete Footing> 6 in.

45˚ bearing angle

Soil Resistive Force

Design Bearing Area

Post (min 6x6)

Concentrated Load

6 in.

Grade


FOUNDATION

Concrete belled pier foundation

Potential issues?

Post (min 6x6)

Concentrated Load

Max 30˚ angle

> 6 in.

Bearing Area

Grade

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FOUNDATIONBuried PT post on concrete footing

Potential issues?

Concrete Footing> 6 in.

45˚ bearing angle

Post (min 6x6)

Concentrated Load

6 in.

Grade


USEFUL RESOURCES

2018 Significant Changes Books

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USEFUL RESOURCES

2015 DCA 6 –Residential Wood Deck Construction Guide


USEFUL RESOURCES

BCD307 – Deck FAQs: Deciphering DCA6 and More

BCD303 – Residential Wood Deck Design

AWC Webinars

https://awc.org/education

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T h i s p r e s e n t a t i o n i s p r o t e c t e d b y U S a n d I n t e r n a t i o n a l C o p y r i g h t l a w s . R e p r o d u c t i o n , d i s t r i b u t i o n , d i s p l a y a n d u s e o f t h e p r e s e n t a t i o n w i t h o u t w r i t t e n p e r m i s s i o n o f A m e r i c a n W o o d C o u n c i l ( A W C ) i s

p r o h i b i t e d . © A m e r i c a n W o o d C o u n c i l 2 0 1 9

in [email protected] | www.awc.org

Speaker contact info:

Sandra Hyde International Code CouncilSenior Staff Engineer

[email protected] x7755

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