2018 IBC Essentials for Wood Construction · (AWC) and the International Code Council (ICC), this presentation concisely summarizes the 2018 International Building Code (IBC)for commercial
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2018 IBC Essentials for Wood ConstructionBased on Code Conforming Wood Design, 2018 Edition and the 2018 International Building Code® (IBC®)
Paul Coats, P.E., C.B.O.Southeast Regional ManagerAmerican Wood Council
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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 DESCRIPTION
Based on the popular Code Conforming Wood Design (CCWD), a joint publication of the American Wood Council (AWC) and the International Code Council (ICC), this presentation concisely summarizes the 2018 International Building Code (IBC) for commercial and multi-family residential construction. It will explain the determination of maximum building size for eight common use groups using the height and area tables of the 2018 IBC and pre-calculated tables provided in the CCWD. It will also address establishing fire resistance for wood assemblies and heavy timber; special provisions for pedestal buildings; criteria for finishes, appendages, and other wood features; the scoping of referenced wood design standards; an overview of structural provisions in Chapter 23; and requirements for precautions during construction. Participants may download a complimentary copy of the CCWD at: http://www.awc.org/codes/ccwdindex.html
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LEARNING OBJECTIVESUpon completion, participants will be better able to identify:
Identify maximum building size and use parameters for wood as the primary structural elements.Identify the sources of structural provisions when using wood as the structural frame.
Structural Elements
Identify special provisions for design of wood structures that involve compartmentalization and sprinkler systems.
Special Provisions
Identify methods specified by the code for establishing fire resistance of wood assemblies and elements and fire precautions during construction.
Fire Resistance
Apply code provisions for the non-structural use of wood in buildings, such as for finishes, appendages, siding and trim.
Non-Structural Use
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2018 CODE CONFORMING WOOD DESIGN
CCWD includes• Allowable building size• Special occupancies• Fire resistance• Building features• Wood in noncombustible construction types• Structural considerations• Precautions during construction
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• The ICC is a member-focused association
• It is dedicated to developing model codes and standards used in the design, build and compliance processes to construct safe, sustainable, affordable and resilient structures
• More info at iccsafe.org
INTERNATIONAL CODE COUNCIL (ICC)
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POLLING QUESTION
1. What is your profession?a) Architectb) Engineerc) Code Officiald) Fire Servicee) Builder/Product Manufacturer/Other
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FIRE-RETARDANT-TREATED WOOD (FRTW) There are many additional applications for fire-retardant-treated wood (FRTW) in Type I and II construction (603)
• Permitted in nonbearing partitions where the fire-resistance rating does not exceed two hours
• Nonbearing exterior walls (unrated)• Roof construction, including structural
framework, permits FRTW, except for Type IA construction of three stories or more where the lowest roof member is less than 20 feet measured vertically from the upper floor
• Balconies, porches, decks and exit stairways not used as required exits on buildings three stories or less above grade
• Can be used in exterior walls of Types III and IV
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HEAVY TIMBER (HT)
Permitted in roof construction as an alternative to 1-hour or less fire-resistance rated noncombustible construction (Table 601 footnote c, except Type IA buildings)
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Introduced in the 2015 IBC• Specifically called out in Type IV
construction• Permitted in Type III, IV, and V buildings• The AWC NDS contains provisions for CLT• A product standard, ANSI/APA PRG 320• E119 test report available
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Fire resistance of wood frame assemblies also may be calculated based on the known fire resistance of the components,using the provisions of Section 722.6
CALCULATED RESISTANCE (703.3)
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703.3 Methods for Determining Fire Resistance
METHODS FOR DETERMINING FIRE RESISTANCE (703.3)
Item 4: Engineering analysis based on a comparison of building element, component or assemblies designs having fire-resistance ratings as determined by the test procedures set forth in ASTM E 119 or UL 263
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703.3 Methods for Determining Fire Resistance. The application of any of the methods listed in this section shall be based on the fire exposure and acceptance criteria specified in ASTM E119 or UL 263. The required fire resistance of a building element, component or assembly shall be permitted to be established by any of the following methods or procedures:
1. Fire-resistance designs documented in approved sources.2. Prescriptive designs of fire-resistance-rated building elements, components or
assemblies as prescribed in Section 721.3. Calculations in accordance with Section 722.4. Engineering analysis based on a comparison of building element, component,
or assemblies designs having fire-resistance ratings as determined by the test procedures set forth in ASTM E119 or UL 263.
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703.3 Methods for Determining Fire Resistance. The application of any of the methods listed in this section shall be based on the fire exposure and acceptance criteria specified in ASTM E119 or UL 263. The required fire resistance of a building element, component or assembly shall be permitted to be established by any of the following methods or procedures:
(items 1 – 4 on previous slide)5. Alternative protection methods as allowed by Section 104.11.6. Fire-resistance designs certified by an approved agency.
METHODS FOR DETERMINING FIRE RESISTANCE (703.3)
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POLLING QUESTION
2. Which of the following is an approved method to determine fire-resistance?a) Tested fire assembly (ASTM E119 or UL 263)b) Fire resistance designs documented in approved sourcesc) Prescriptive fire-resistance-rated assemblies/elements in
Section 721d) Calculation of fire resistance per Section 722e) All of the above
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• Method of floor constructions• Employs individual wood members set on edge and connected
• Required to be square-end trimmed and supported in one of five layup patterns
• Simple span• Two-span continuous• Combination simple and two-span continuous• Cantilevered pieces intermixed• Controlled random
LUMBER DECKING (2304.9)
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• Common for designed structures to have greater fastening requirements than to those prescribed in Table 2304.10.1
• Where wall framing members are not continuous from the foundation sill to the roof, a continuous load path using sheet metal clamps, ties or clips must be provided and must be corrosion resistant (often galvanized steel) if they are subject to moisture
• Joist and framing anchors may be used in accordance with the manufacturer’s instructions, and other fasteners such as clips, staples, and glues are permitted when approved by the building official
• Fasteners in contact with preservative-treated and fire-retardant wood are required to be corrosion resistant
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• The provisions of Section 2308 are prescriptive and limited in scope and application—generally building construction having closely spaced framing (not exceeding 24 inches on center) with studs up to 2 x 6 inches in size and rafters up to 2 x 12 inches in size
• Height limits range from one story in Categories D and E to three stories in Categories A and B
• Maximum floor-to-floor height is 11-feet, 7-inches in all seismic zones
• Exterior bearing walls and interior bracing walls are limited to a stud height of 10 feet
• Allowable loads and wind speeds are limited (e.g., live loads not exceeding 40 psf, Vult < 130 mph)
CONVENTIONAL LIGHT FRAME (2308)
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The Wood Frame Construction Manual may be used for commercial buildings within its scope and the following limitations:
• Risk Category I and II buildings only• The maximum building dimensions and
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Single Occupancy, One-Story Buildings (506.2.1)
ALLOWABLE BUILDING AREA
Where:• Aa = Allowable building area (square feet)• At =Tabular building area factor (NS, S1, or S13R value, as applicable) in accordance
with Table 506.2 (square feet)• NS =Tabular allowable area factor in accordance with Table 506.2 for a nonsprinklered
building (regardless of whether the building is sprinklered)• If = Area factor increase due to frontage (percent) as calculated in accordance with
Section 506.3
Aa = At + (NS × If) (Equation 5-1)
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ALLOWABLE BUILDING AREASingle Occupancy, Multi-story Buildings (506.2.3)
Where:• Aa = Allowable building area (square feet)• At =Tabular building area factor (NS, S13R, or SM value, as applicable) in accordance with
Table 506.2 (square feet)• NS =Tabular allowable area factor in accordance with Table 506.2 for a nonsprinklered
building (regardless of whether the building is sprinklered)• If = Area factor increase due to frontage (percent) as calculated in accordance with Section
506.3• Sa = Actual number of building stories above grade plane, not to exceed three. For buildings
equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2 (NFPA 13R system), use the actual number of building stories above grade plane, not to exceed four
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ALLOWABLE BUILDING AREA CALCULATION Solution continued:
Total Allowable Area (Section 506.2.3)
Aa = At + (NS x If)Aa = 38,000 + (9,500 × 0.25) = 40,375 square feet
Actual area = 250 × 100 = 25,000 square feet OK
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For many occupancies, Chapter 5 will yield floor area limits that exceed those permitted in Chapter 9 for nonsprinklered buildings
• The same thresholds apply to all construction types, not just wood. The allowable area per story must not exceed allowable fire areas and a sprinkler system may be required
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Buildings three or more stories above grade have a total building area per story found in (Aa) calculated by Equation 5-2 with a value of three for the number of stories (Sa)
TOTAL AREA BUILDING LIIMIT (506.2.3)
Sa = Actual number of building stories above grade plane, not to exceed three. For buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2, use the actual number of building stories above grade plane, not to exceed four
This is built-in to:
Aa = At + (NS × If) Equation 5-1 Aa = [At + (NS × If)] × Sa Equation 5-2
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BUILDING AREA – 3-STORIES
3-Story BuildingTotal Allowable Building AreaAa = 3 × At (single story)
where:Aa = allowable building areaAt = allowable building area per story
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BUILDING AREA – MORE THAN 3-STORIES
4 and 4+ Story BuildingTotal Allowable Building AreaAa= 3 × At (single story)
where:Aa = allowable building areaAt = allowable building area per story
Stories of equal area: • Each story may not exceed 112,500/4 = 28,125 sq. ft.
Stories of unequal area: • No single story can exceed 37,500 sq. ft.
Max. 37,500 x 3 = 112,500 sq. ft.
4-story building
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POLLING QUESTION
3. For single occupancy buildings with 4 or more stories, the total allowable building area isa) Two times the allowable area per storyb) Three times the allowable area per storyc) Four times the allowable area per storyd) Number of stories times the allowable area per story
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FOOTNOTES – GROUP ENonsprinklered Buildings
Footnotes• Frontage based on open space widths of
30 feet or more• Interpolation permitted• Sprinklers must be provided for Group E
occupancies when the fire area exceeds 12,000 square feet in accordance with Section 903.2.3, or by reason of other specific conditions in that section. In lieu of sprinklers, compartmentalization of the floor area into fire areas not more than 12,000 square feet can be provided with fire-resistance-rated construction in accordance with Chapter 7
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60′
40′
250′
100′
EXAMPLE – GROUP E
Given: • Single-story Type VB grade
school• Provided with an NFPA 13-
compliant automatic sprinkler system throughout and located on lot as shown.
• The maximum floor area for four stories above grade plane was determined in accordance with Section 506.2.3 and using a value of Sa = 4 as permitted when using an NFPA 13R sprinkler system
• Frontage based on open space widths of 30 feet or more• Interpolation permitted• Section 903.2.6 permits Group I-1 occupancies to be sprinklered with an NFPA 13R-
compliant system. The occupancies do not qualify for area increases due to sprinklers• Type VB construction does not permit three stories above grade plane
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UNLIMITED AREA ONE-STORY SPRINKLERED BUILDINGS
Unlimited area Group B, F, M and S • Limits in Section 507.4.• Building must be equipped throughout with an NFPA 13-compliant automatic sprinkler
system• Must be surrounded on all sides by public ways or yards not less than 60 feet wide
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UNLIMITED AREA ONE-STORY SPRINKLERED BUILDINGS
Group A-1 and A-2 occupancies are allowed in unlimited area mixed occupancy buildings containing Group B, F, M or S occupancies
• Limits in Section 507.4.1.• Type III or IV construction.• Occupancies are separated as required in Section 508.4.4.• A-1 and A-2 portions shall not exceed maximum allowable areas permitted by Section 503.1. • All exit doors from Group A-1 and A-2 occupancies must discharge directly to the exterior of
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Up to 75 percent of the perimeter open space may be < 60 feet in width, provided:
There is at least 40 feet open width provided and the exterior wall and all openings on those portions require 3-hour minimum fire-resistance and fire protection ratings
REDUCED OPEN SPACE (507.2.1)
450 ft100 ft100 ft
450 ft
70 ft
40 ft65 ft
45 ft
3-hr fire rating required on walls and all openings
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Fire walls define separate buildings for allowable building size (706)
• Not fire barriers (707)
• Not fire partitions (708)
• Not smoke barriers, smoke partitions or horizontal assemblies
• Table 706.4 gives required ratings based on occupancies separated
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903.3.1.2.3 includes requirements for the protection of attics in buildings of Types III, IV, and V construction when using Sections 510.2 and 510.4:
• Alternative for attic protection are sprinklers, noncombustible construction, FRTW construction, or filling entire space with noncombustible insulation
• Protection applies when the roof assembly is more than 55 feet above the lowest level of required fire department access (see section for measuring height of roof in this circumstance)
• See additional requirements for the protection of attics when used for living or storage, when fuel-fire equipment is present, and in R-4 Condition 2 occupancies
ATTIC PROTECTION
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• Mixed occupancy buildings are permitted a total allowable building area calculated in accordance with Section 508
• Single-story basement does not need to be included in the total allowable building area when the basement does not exceed the area permitted for a single-story per Section 506.1.3
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• Structure’s purpose not listed• Classified as most nearly
resembled occupancy
• Section 302.1
USE AND OCCUPANCY CLASSIFICATION
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• Eight occupancy classifications• Group A, Assembly • Group B, Business • Group E, Educational • Group F, Factory/Industrial • Group I, Institutional • Group M, Mercantile• Group R, Residential • Group S, Storage
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POLLING QUESTION
4. Which of the following occupancy classifications applies to residential care and assisted living facilities for 6-16 clients?a) I-1b) I-4c) R-3d) R-4e) None of the above
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Wood foundations for buildings are permitted when designed and installed in accordance with the AWC Permanent Wood Foundation Design Specification (PWF)
WOOD FOUNDATIONS (1807.1.4)
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Wood materials may be used as interior finish in almost all occupancies
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WOOD INTERIOR TRIM (806)
• Trim is required to meet a Class C classification
• Combustible trim, excluding handrails and guards, cannot exceed 10 percent of the wall or ceiling area to which it is attached (806.7)
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EXTERIOR WINDOWS AND DOORS
Exterior openings are required to be protected with fire protection rated window or door assemblies when the exterior wall is within given distances of a lot line (705.8)
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Unlimited amounts of unprotected openings are permitted by Table 705.8
• When exterior walls are 30 feet or more from the lot line• 20 feet or more from the lot line (sprinklered buildings)• 10 feet or more from the lot line (Types IIB or VB construction) (705.8.1
exception 2)
No unprotected openings are permitted in the exterior wall • Within five feet of the lot line (nonsprinklered buildings)
No openings • When wall is closer than three feet from the lot line
EXTERIOR WINDOWS AND DOORS
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INTERIOR WINDOWS AND DOORSInterior wood door assemblies are required to be fire-protection rated when the wall assembly they are in requires a FRR and opening protection (Table 716.1(2))
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WOOD SIDING
• Wood siding is regulated in 1405 (see height limits as combustible exterior wall covering)
• Minimum thicknesses for wood siding in 1404.2 and restrictions for exterior wood veneers in 1404.5
• See Chapter 23 for wood siding as a structural building material
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WOOD BALCONIES (705.2.3.1)Exterior balconies may be of Type IV construction or of wood construction that provides a fire-resistance rating equal to the floor rating required by Table 601
• Length limited to 50 percent of perimeter, each floor
• See exceptions for sprinkler-protected balconies
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OPEN EXTERIOR STAIRS AND RAMPS
Open exterior exit stairs and ramps may be constructed of wood when the building is of Type IV and V construction (Sections 1011.7 and 1012.7)
• Buildings up to six stories and no high-rise
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Types III, IV and V construction
• Projections of any material are permitted, subject to the limitation of Section 705.2.3
• Combustible projections located where protection of some openings is required or within five feet of the lot line (or other line used to determine the fire separation distance) must be one of the following:
• Minimum 1-hour fire-resistance-rated construction
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If required by the fire code official, a fire watch must be provided during nonworking hours when construction exceeds 40 feet in height above lowest adjacent grade
• The IFC has other more extensive requires for fire watches
• Section 3302.3 of the IBC requires compliance with the IFC for construction fire safety
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During construction, one portable fire extinguisher must be placed at:
• Each stairway on all floor levels with combustible materials
• Each storage or construction shed and where special hazards exist
FIRE EXTINGUISHER (3309)
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During construction, when a building height reaches 40 feet above lowest level of fire department vehicle access, a minimum of one temporary or permanent stairway must be provided. As construction progresses, the stairway shall extend to within one floor of the highest level with secured decking or flooring
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POLLING QUESTION
5. If required by the fire code official, a fire watch must be provided during nonworking hours when construction exceeds 40 feet in height above lowest adjacent grade?a) Trueb) False
This concludes the American Institute of Architects Continuing Education Systems CourseThis concludes the American Institute of Architects Continuing Education Systems Course