Topic

Old Code (CABO)

New Code (IRC)

Foundation

R401

Section R401.1: added exception #2, concerning foundations in areas prone to flooding

Geotechnical evaluation

R401.4.1

R401.4.1…revised table…added notes a & b, under Class Of Materials added, and foliated rock, added silt and sandy silt, and abbreviations for soil types

Wood treatment

R402.1.2

R402.1.2 section was reworded

Concrete

R402.2

R402.2, all materials used to produce concrete shall comply with ACI318 and cement complying with ASTMC1157 is permitted

Footings

R403

R403.1 section was reworded, basically the same content

Footings

R403.1.1 (slope)

R403.1.5, new section number, same content, sections R403.1.2 through R403.1.4 do not apply in Wake County

Footings

R403.1.1, minimum size footings (new section)

Foundation anchorage

Figure 403.1a, note # 5 omitted

R403.1.6

Footings  on or adjacent to slopes

Section did exist

R403.1.7 deleted

Insulated footings

R403.3

Section deleted

Design required

R404.1.2

Section R404.1.3 design required when the foundation wall is subject to hydrostatic pressure and walls supporting more than 48" of unbalanced fill without permanent lateral support at the top and bottom.

Foundation walls, seismic requirements

R404.1.4 does not apply in Wake County.

Foundation wall thickness based on wall support

R404.1.5

Pier and curtain wall

R604.5.2

R404.1.5.1 section was relocated

Piers

R604.5

R404.1.5.2 section was relocated

Height above finished grade

R404.1.3, foundation wall shall extend 8" above grade, brick veneer: 4" above grade

R404.1.6, foundation wall shall extend 4" above grade, brick veneer 6" above grade

Backfill placement

R404.1.3.1, exception: bracing not required for unbalanced fill of less than 3'-0"

R404.1.7, exception: changed to 4'-0"

Rubble stone masonry

R604.2.2

R404.1.8, added maximum 8'-0" of unbalanced fill and maximum soil pressure of 30psf

Wood foundation walls

R404.3

R404.2

Wood grade

R404.3.1

R404.2.1 reworded to be more specific

Fastening

R404.2.6 new section

Wood sill plates

R404.3, new section, minimum sill plate 2"x4"

Insulating concrete form foundation walls (ICF)

R404.4 new section, if walls are designed in accordance with ACI318 or this section, seal of an architect or engineer is not required

Foundation drainage

R405.1, exception #2 was added, system is not required when the interior grade is less than 12" below the exterior grade

Concrete and masonry foundation waterproofing

R406.2, Exception was added

Final grade

R406.3.5

Omitted

Foundation insulation

R407

Omitted

Columns

R408

R407.3, added exception for seismic design categories A,B,C (Wake Co. is in category B)

Crawl space ventilation

R409.1

R408.1, added "one such ventilating opening shall be within 3' of each corner

R409.1

R408.2, exception #2 revised: one ventilation opening does not have to be within 3' of each corner and operable vents are not permitted

R409.1, exception # 3 was omitted in the IRC

R408.2, exception # 5 is a new item where the ventilation is not required when the ground is covered with an approved vapor barrier, the space is supplied with conditioned air and the walls are insulated

Finished grade

R409.4, ground water table cannot rise within 6" of the finished floor at the building perimeter

408.5 revised, ground water table cannot rise within 6" of the finished grade of the under-floor space at the building perimeter

Flood resistance

R408.6 new section

TOPIC

VOL VII (old)

IRC (new)

Prefabricated wood I-joist

R502.2 Prefabricated wood I-joists. Requirements shall be in accordance with ASTM D 5055.

Decks

501.3 Exterior Decks …shall be in accordance with Appendix A.

R502.2.1 Decks..refer to table R301.4 for live load …also decks shall be permitted to be constructed in accordance with Appendix M.

Allowable Joist Spans

502.3.1 Allowable joist spans refer to tables 502.3.1a through 502.3.1b

R502.3 Allowable joist spans. Refer to new tables R502.3.1(1) And R502.3.1(2). Note: these tables have been simplified & are much easier to read (also note sleeping areas & living areas.

Wood wall framing

R602.2.2, new section, End joint lumber

Design and construction

R602.3, section was called Exterior Walls

R602.3, new section is called Design and Construction, added "or in accordance with AF&PA's NDS

Stud spacing

R602.3.1

R602.3.1, added bearing studs greater than 10 feet, see table R602.3.1

Top plate

R602.3.2, end joints shall be offset at least 48".

R602.3.2, end joints shall be offset at least 24".

Bottom (sole) plate

R602.3.4 studs shall have full bearing on a nominal 2 by or larger plate.

Drilling and notching of studs

R602.5

R602.6

Added exceptions # 2,3

Drilling and notching of the top plate

R602.5.1 used 24 gauge angle to repair cut top plate

R602.6.1 revised, must use 16 gauge angle to repair cut top plate. Added an exception, use of wood structural sheathing

Fastener schedule for structural members

Table 602.3a

Double top plates, minimum 48" offset of end joints, face nailed in lapped area, nail with 4-10d

Table 602.3 (1)

Double top plates, minimum 48" offset of end joints, face nailed in lapped area, nail with 8-16d

Added: blocking between joists or rafters to top plate, toe nail with 3-8d

Added: rim joist to top plate, toe nail with 8d, 6"oc

Added: other wall sheathing, ½" regular cellulosic fiberboard sheathing, ½" structural cellulosic fiberboard sheathing

** subnotes were changed from a number system to a letter system

revised subnote f from 90 mph to 110 mph

revised subnote g from 80 mph to 100 mph

Added subnote I

Alternate attachments

Table 602.3a (1)

Table 602.3 (2)

Changed all sub notes from numbers to letters. Subnote c revised: Nails or staples shall be spaced at no more than 12" on center at intermediate supports for floors. Added subnote f.

Wood structural panels subfloor, etc., 5/16"; 3/8" ; 15/32" ; ½"  added staple 16 ga. 1 ¾"

23/32" and ¾" added staple 16 ga. 2"

Floor underlayment, etc.

Plywood

¼" and 5/16" added staple 18 ga. 7/8", 3/16" crown width

19/32", 5/8", 23/32", ¾" added staple 16 ga. 1 1/4"

Exterior bearing walls

First floor of 3 story

Exterior non bearing walls

Table 602.3e

Wind zone 70 mph

Wind zone 80 mph

Table 602.3e

Wind zone 70 mph

Wind zone 80 mph

Table 602.3 (6)

Wind zone 90 mph

Wind zone 100 mph

Table 602.3 (6)

Wind zone 90 mph

Wind zone 100 mph

Wood structural panel box headers

Figure 602.6.2

Table 602.6.2

Figure 602.7.2

Added sub note # f: galvanized nails shall be hot dipped or tumbled.

Table 602.7.2

Maximum allowable length of wood wall studs exposed to wind speeds of 100 mph or less in seismic design

Categories A, B, C, D

New table 602.3.1

Nonbearing walls

R602.6.4

R602.7.2 (new section number)

Fire blocking

R602.7

R602.8

Basically the same text as the old CABO code but it is more defined and areas where fire blocking are required are more specific.

Cripple walls

R602.8

R602.9

Added: cripple walls with a stud height of less than 14 inches shall be sheathed on at least one side with a wood structural structural panel that is fastened to both the top and bottom plates in accordance with table R602.3 (1), or the cripple walls shall be construction of solid blocking. Cripple walls shall be supported on continuous foundations.

Wall bracing

R602.9

R602.10

Section was completely revised. There is too much material to list here, must study all the new requirements directly from the code.

Steel wall framing

R603 Metal

R603 new section

Wood structural panels

R610

R604

Particle board

R611

R605

General masonry construction

R604

R606

Professional registration not required

R604.1.1

R606.1.1, revised to read : "when the empirical design provisions of ACI 530/ASCE 5/TMS 402 Chapter 5"….

Used brick

R604.1.2

R606.1.2, added an exception for interior non bearing conditions

Parapet walls

R604.2.4

R606.2.4, added: Masonry parapet walls in areas subject to wind loads of 30 pounds per square foot or located in seismic design category D1 or D2 shall be reinforced in accordance with section R606.11.

Roof structures

R604.8.2.1, "Anchors shall be embedded at least 16" into masonry…"

R606.8.2.1, revised: "Anchors shall be embedded at least 15" into masonry…"

Spacing of lateral support for masonry walls

Table604.8

Table R606.8, omitted subnote # 3: For 100mph or greater see chapter 40 for h/t ratios

Anchorage requirements for masonry walls located in Seismic Design Category A,B,C and where wind loads are less than 30psf

Figure 604.10a

Rafter/ceiling joists anchor embedded 4" min.

Joists parallel to wall: ½" bolts at 6ft.o/c embedded at 4 " min.

Figure R606.10 (1)

Rafter/ceiling joists anchor embedded 15" min.

Joists parallel to wall: ½" bolts at 8ft.o/c embedded at 4 " min.

Ledger bolt size and spacing table, decreased joist span from 15'-30' to 15'-20'

Unit masonry

Section R605

Section R607

607.1 Mortar: defines minimum mortar specifications

607.1.1 Foundation Walls and 607.1.2 Masonry in Seismic Design Categories A, B (Wake Co.) and C.

These sections define the minimum mortar specifications for each application.

607.1.3 does not apply in Wake Co.

Bed and head joints

R605.1.1.1

R607.2.1.1: deleted collar joints

Added Exception:

"For the purposes of leveling, the thickness of the bed joint of the starting course placed over the foundation shall not be less than ¼" and not more than 1 ½".

R607.2.1 Bed and Head Joints: "Unless otherwise required or indicated on the project drawings, head and bed joints shall be 3/8" thick.

Mortar Proportions

Table 607.1.1a

Table R607.1

Added mortar cement

Multiple Wythe Masonry

R606

R608

No changes

Grouted Masonry

R607.1.1

R609.1.1. omitted "Only type M or Type S mortar mix consisting of  Portland cement, hydrated lime, and sand in accordance with ASTM C 270…"

Glass Unit Masonry

Section did not exist

R610, new section

Insulating Concrete Form Wall Construction

Section did not exist

R611, new section

Conventionally Formed Concrete Wall Construction

Section did not exist

R612, new section

Exterior Windows and Glass doors

R608, 609, 613

R613, combined the 3 CABO sections into this one new section.

Thickness of Plaster (interior)

Table 702.1a

Table R702.1(1), added gypsum sheathing, changed all subnotes from numbers to letters.

Table R702.1(1), added subnote g

Minimum Thickness and Application of Gypsum Board

Table 702.3.4

Table 702.3.5, application is specific to wall or ceiling. The subnotes are rewritten.

Support

R702.2.1

R702.2.1, added…"16" on center for 3/8" thick….plain gypsum lathe.  Added…."with end joints in adjacent courses staggered by at least one framing space."

Application

R702.3.4

R702.3.5

Fastening

R702.3.5

R702.3.6

Insulating Concrete Form Walls

R702.3.4, new section

Bathtub and shower spaces

R702.4

R307.2

Ceramic Tile

R702.4.1

R702.4.2 GYPSUM BACKER…"shall conform to ASTM C 630 or C 1178."

"ceilings where framing spacing does not exceed 12 inches on center for ½" thick or 16 inches for 5/8 inch thick gypsum board."

Other Finishes

R702.5

R702.5.completely rewritten, see code book

Bottom Course

R702.6.3

R703.5.4

Plaster

R703.6.2 new section

Ceramic Tile

R702.4.1

R702.4.1 General: Ceramic tile surfaces shall be installed in accordance with ANSI A108.4, A108.5, A108.6, A108.11, A118.1, A118.3, A136.1 and A137.1.

R702.4.1

R702.4.2 Gypsum Backer. "….shall conform to ASTM C630 or C1178." "…12 inches on center for 5/8  inch thick or 16 inches on center for ½ inch thick gypsum board."

Other finishes

R702.5

R702.5: completely rewritten.

Exterior Covering

R703.1 General

R703.1 General: added "The exterior wall envelope shall include flashing as described in Section 703.8. 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."

Weather-resistant sheathing paper

R703.2

R703.2…added: "and complying with ASTM D 226"

Exceptions

R703.2.1 Felt or material

No.5. over water repellant sheathing materials

R703.2, Exceptions, no.5 was deleted

Panel Siding

R703.3

R703.1…added: "or shall be shiplapped…..and occur over solid blocking, wood or wood structural panel sheathing."

Plaster

R703.6.2 new section

Panel siding

R703.3.1

R703.3 added "…and occur over solid blocking, wood or wood structural panel sheathing."

Bottom courses (exterior)

R703.5.4: shall be doubled

Weather-resistant siding attachment and minimum thickness

Table 703.4

Table 703.4: added subnotes o,p,q,r.

Stone and masonry veneer

R703.7

R703.7, revised for Wake Co., max. ht. of 30 feet above the noncombustible foundation, with an additional 8 feet permitted for gable ends.

Anchorage

R703.7.2

R703.7.4, rewritten (see IRC)

Air space

Figure 703.7(b)

R703.7.4.2, min.1", max. 4.5"

Mortar or grout fill

R703.7.2.3

R703.7.4.3, rewritten (see IRC)

Flashing

R703.7.3

R703.7.5, rewritten (see IRC)

Flashing

R703.8

R703.8, rewritten (see IRC)

Exterior insulation finish systems

Did not exist

R703.9, new section (see IRC)

Masonry veneered wall detail

Figure 703.7(b)

Figure R703.7, R703.7.1

IRC

R802.9, added "Approved hangers shall be used for the header to trimmer connections when the header span exceeds 6 feet. Tail members over 12 feet long shall be supported at the header by framing anchors or on ledger strips not less than 2 inches b 2 inches."

Exception: all dormers shall have double headers and double rafters.

R802.10: section has been completely rewritten (see IRC).

R802.11: section has been rewritten, table R802.11 replaces table 802.12.

Wood structural panel sheathing

R803.2 (plywood sheathing)

R803.2.1.3 (wood structural panels)

R803.3 (particle board)

R803.2: combined all of the CABO sections into one section.

Steel roof framing

R804: completely new section must see new IRC.

Attic access

R807.1: added, "In buildings with combustible ceiling or roof construction, an attic access opening shall be provided to attic areas that exceed 30 sq. ft. and have a vertical height of 30 inches or greater.  The roughed framed opening shall not be less than 22 inches by 30 inches and shall be located in a hallway or other readily accessible location. A 30 inch minimum unobstructed headroom in the attic space shall be provided at some point above the access opening."

Allowable spans for ceiling joists

Tables have been redesigned to reflect spans and live loads to the different species of lumber.

Insulation clearance

R808: new section, "combustible insulation shall be separated a minimum of 3 inches from recessed lighting fixtures, fan motors and other heat producing devices."