Exam Cheat Sheet · Quick Reference

ICC G12 General Building Contractor (B) Exam (2018 IBC/IRC)

National  ·  Pearson Vue

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
80
Passing score
70%
Exam time
240 min
Administered by
Pearson Vue
Format
Reference materials allowed

National State Portion 80 questions

Permits and General Regulations 17 Q · 21%
Regulations and Job PlanningCode Definitions and TermsPermit application requirements and proceduresWork exempt from permit requirementsBuilding official duties, powers, and authorityRequired inspections and inspection sequenceCertificate of occupancy issuance and requirementsStop work orders and violation enforcementBoard of appeals process and limitationsPermit validity, expiration, and suspension
Building Planning and Life Safety 24 Q · 30%
Use & Occupancy & Types of ConstructionFire & Smoke Alarms & Fire Protection SystemsOccupancy Needs & Interior EnvironmentExiting & Means of EgressAccessibilityBuilding height and area limitations by occupancy and construction typeAllowable story counts and sprinkler system increasesFire-resistance ratings for building elements and exterior wallsMezzanine area limitations and openness requirementsOccupant load calculation and posting requirementsMeans of egress sizing, capacity factors, and minimum widthsEgress doors — swing, hardware, locking, and special door requirements +1 more
Structural Systems 33 Q · 41%
Footings and FoundationsConcreteFloorsWall Framing and StairsRoof Ceiling Construction Roof AssemblyMasonryStructural loads and load combinations (dead, live, wind, snow, seismic)Wall bracing methods and braced wall panel requirementsWood structural design methods (ASD, LRFD, conventional light-frame construction)Wood truss design, fabrication, and installation requirementsLumber grading, species, and engineered wood product standardsGeotechnical investigations and soil classification +5 more
Building Envelope 6 Q · 8%
Interior FinishesGlass and GlazingExterior Finishes and Roof CoveringsWater-resistive barriers and vapor retarders in exterior wallsFlashing requirements and locations (walls and roofs)Roof covering types, slope requirements, and minimum installation standardsUnderlayment types, application, and attachment requirementsRoof drainage, scuppers, and secondary overflow systemsFire classification of roof assemblies and exterior wall coveringsRooftop structures (penthouses, cooling towers, mechanical screens)Gypsum board and plaster materials, installation, and limitations

Key Distinctions

Dwelling unit (IBC Ch. 2)vsSleeping unit (IBC Ch. 2)

A dwelling unit has complete independent living facilities with permanent provisions for living, sleeping, eating, cooking AND sanitation, while a sleeping unit may have living, eating and either sanitation or kitchen facilities but not both.

IBC 2018 Chapter 2 (Definitions), 'Dwelling Unit' and 'Sleeping Unit'
NFPA 13R sprinkler systemvsNFPA 13 sprinkler system

NFPA 13R is permitted in Group R occupancies only up to and including four stories and not exceeding 60 feet above grade plane, whereas allowable-area computations with a full NFPA 13 system cap Sa at three stories (four stories only for NFPA 13R per Section 903.3.1.2).

IBC 2018 Page 222
Townhouse double-wall separation (IRC R302.2.1)vsTownhouse common-wall separation (IRC R302.2.2)

Under the double-wall option each townhouse is separated by two 1-hour fire-resistance-rated wall assemblies (ASTM E119, UL 263 or IBC 703.3), while the 1-hour and 2-hour single-wall ratings belong to the common wall option.

IRC 2018 Chapter 3 — Section R302.2.1 (Double walls)
MarkvsLabel

A mark is applied by the manufacturer and gives only the manufacturer's name and the product's function; a label additionally carries performance characteristics and the name/identification of an approved agency (and a manufacturer's designation indicates compliance with a specified standard or set of rules).

IBC 2018 Chapter 2 (Definitions), 'Mark'
Approved sourcevsApproved agency

An approved source is an independent person, firm or corporation approved by the building official, competent and experienced in applying engineering principles to materials, methods or systems analyses; an approved agency is one regularly engaged in conducting tests, furnishing inspection services or product certification.

IBC 2018 Chapter 2 (Definitions), 'Approved Source'
Labeled (IRC Ch. 2)vsListed / Approved (IRC Ch. 2)

Labeled means an identifying mark of a nationally recognized testing laboratory or approved agency is affixed and that organization maintains periodic inspection of production; listed means inclusion in a published list, and approved means acceptable to the building official.

IRC 2018 Chapter 2 — Definitions (Labeled, Listed, Approved)
Fixed seating without dividing armsvsSeating booths

Occupant load for fixed seating without dividing arms is not less than one person per 18 inches of seating length, while booths are computed at one person per 24 inches of booth seat length measured at the backrest.

IBC 2018 Page 259
Type III (high-early-strength) cementvsType I cement

Type III can have nearly the same setting times as Type I but develops strength much faster once set — reaching Type I's normal 7-day strength in about 3 days and its normal 28-day strength in about 7 days, with rapid heat of hydration.

Concrete Manual (2015 IBC / ACI 318-14), Chapter 1 — Section 1.2 (The Hydration Reaction)
Type V cementvsType II cement

For concrete exposed to sulfate soils or solutions, Type V sulfate-resistant cement should be specified in severe exposures and Type II in moderate exposures (Type III is high-early-strength, not sulfate-resisting).

Concrete Manual (2015 IBC / ACI 318-14), Chapter 4 — Section 4.2 (Deficiencies of the Concrete Itself)
Volumetric method for air contentvsGravimetric method / Chace meter

The volumetric meter measures air from the change in water column height after agitation, needs no knowledge of batch materials or proportions and may be used in lightweight concrete; the gravimetric method requires specific gravities and batch proportions, and the Chace meter is only an approximation.

Concrete Manual (2015 IBC / ACI 318-14), Chapter 2 — Section 2.8 (Air Content)
Cylinders cured under controlled temperature and humidityvsCylinders cured under job/field conditions

Controlled-cured cylinders are made to determine compliance with the specifications (ACI 318 26.12.3), while field-cured cylinders are made to determine the time for removal of shoring or forms or when the structure can be placed in service (ACI 318 26.5.3.2).

Concrete Manual (2015 IBC / ACI 318-14), Chapter 3 — Section 3.8 (Job-Molded Specimens)
Rafter/ceiling joist on a 2-inch nominal sill platevsRafter/ceiling joist bearing directly on masonry or concrete

Where a 2-inch minimum nominal sill plate is used, it must provide a minimum nominal bearing area of 48 square inches; direct bearing on masonry or concrete requires not less than 3 inches of bearing.

IRC 2018 Section R802.6
Change of occupancyvsAddition

A change of occupancy is a change of occupancy classification, a change between groups within a classification, or any change in use within a group that changes the application of code requirements; an increase in floor area is an addition, and a change of ownership alone is neither.

IBC 2018 Chapter 2 (Definitions), 'Change of Occupancy'

Key Terms

Dwelling unit IBC 2018 Chapter 2 (Definitions), 'Dwelling Unit' and 'Sleeping Unit'
A single unit providing complete, independent living facilities including permanent provisions for living, sleeping, eating, cooking and sanitation (2018 IBC Ch. 2).
Townhouse (IBC definition) IBC 2018 Chapter 2 (Definitions), 'Townhouse'
A single-family dwelling unit constructed in a group of three or more attached units, each extending from the foundation to the roof and with open space on at least two sides; no maximum number of units is set.
Townhouse scope under the IRC IRC 2018 Section R101.2
Per IRC R101.2, the residential code applies to townhouses not more than three stories above grade plane with a separate means of egress for each unit, plus accessory structures not more than three stories above grade plane.
Existing building IBC 2018 Chapter 2 (Definitions), 'Existing Building'
A building erected prior to the date of adoption of the appropriate code, or one for which a legal building permit has been issued (2018 IBC Ch. 2).
Public way IBC 2018 Section 202 (Definitions)
A street, alley or other parcel of land open to the outside air leading to a street, deeded, dedicated or otherwise permanently appropriated to public use, with a clear width and height of not less than 10 feet (IBC 202).
Substantial improvement (flood hazard area) IRC 2018 Section R105.3.1.1
Per IRC R105.3.1.1, work whose value equals or exceeds 50 percent of the market value of the building before the damage occurred or the improvement is started, which then requires the existing portions of the entire building to meet the flood-resistant requirements of Section R322.
Report of inspection by an approved agency IBC 2018 Chapter 1 (Scope and Administration), Section 104.4
Under IBC 104.4 the building official may accept such reports in lieu of personal inspection, but they must be in writing and certified by a responsible officer of the approved agency or by the responsible individual.
Permit application contents IBC 2018 Chapter 1 (Scope and Administration), Section 105.3
IBC 105.3 requires the written application to identify the work, give the legal description of the land, state the intended use and occupancy, include construction documents, state the valuation of the proposed work, and be signed by the applicant.
Permit expiration IBC 2018 Chapter 1 (Scope and Administration), Section 105.5
Per IBC 105.5 a permit becomes invalid unless work authorized on the site is commenced within 180 days of issuance, or if work is suspended or abandoned for 180 days after commencement; the building official may grant written extensions of not more than 180 days each.
Permit exemption for storage sheds IBC 2018 Chapter 1 (Scope and Administration), Section 105.2
Under IBC 105.2 one-story detached accessory tool and storage sheds are exempt only where the floor area is not greater than 120 square feet, so a 150-square-foot shed requires a permit.
Framing inspection IBC 2018 Chapter 1 (Scope and Administration), Section 110.3.4
Per IBC 110.3.4, made after the roof deck or sheathing, all framing, fireblocking and bracing are in place, concealed pipes, chimneys and vents are complete, and the rough electrical, plumbing and heating wires, pipes and ducts are approved.
Stop work order IBC 2018 Chapter 1 (Scope and Administration), Section 115.2
Per IBC 115.2, an order that must be in writing, given to the owner, the owner's authorized agent or the person performing the work, stating the reason for the order and the conditions under which the cited work will be permitted to resume; cited work must cease immediately.
Smokeproof enclosure vestibule IBC 2018 Page 249
Per IBC 909.20.1 the vestibule shall be not less than the required width of the corridor leading to it, but in no case less than 44 inches wide and not less than 72 inches long in the direction of egress travel.
Class B interior wall and ceiling finish IBC 2018 Chapter 8 — Section 803.1.2
Per IBC 803.1.2, material with a flame spread index of 26–75 (ASTM E84 or UL 723) and smoke-developed index of 0–450; Class A is 0–25 and Class C is 76–200.
Laitance Concrete Manual (2015 IBC / ACI 318-14), Pages 342 and 348 (Chapter 17, Sections 17.1 and 17.2)
The weak sand-cement wearing surface formed when tools are used on fresh concrete while bleed water is present, bringing excess water and fines to the top so the surface later dusts (Concrete Manual 17.1, 17.2).
Modulus of rupture Concrete Manual (2015 IBC / ACI 318-14), Chapter 3 — Section 3.4 (Flexural Strength)
A measure of flexural strength determined by testing a small beam, usually 6 by 6 inches in cross section, in bending with a concentrated load applied at each of the third points (Concrete Manual 3.4).
Emergency escape and rescue door IRC 2018 Chapter 3 — Section R310.3 (Emergency escape and rescue doors)
Per IRC R310.3, where a door serves as the required emergency escape and rescue opening it shall be a side-hinged door or a slider, with an area well required where the opening is below adjacent grade.
Watertight concrete Concrete Manual (2015 IBC / ACI 318-14), Chapter 23, Section 23.1 (Book Page 504)
Per Concrete Manual 23.1, concrete built watertight using sound, well-graded, low-porosity aggregates and a plastic, workable, thoroughly mixed mix with a water-cement ratio not exceeding 0.50, avoiding high-slump mixes, consolidated by vibration and given at least seven days of continuous wet curing or a reliable curing compound.

Formulas to Know

Water-cement ratio converted to gallons of water per bag of cement (worked example from the manual)W/C 0.44 by weight × 94 lb/bag = 41.4 lb water; 41.4 lb ÷ 8.33 lb/gal ≈ 5.0 gallons per bag (manual's stated example: W/C = 0.44 = 5 gal/bag)
Maximum contraction joint spacing, continuous floor slabs on groundSpacing shall not exceed 30 × slab thickness in both directions, for well-proportioned concrete with aggregates of normal shrinkage, unless reliable data justify wider spacing; panels as nearly square as practical (Concrete Manual 16.2)
Maximum size of coarse aggregate (MSA) when not specifiedMSA shall not exceed 1/3 the depth of a slab, 3/4 of the minimum clear spacing between reinforcing bars or between bars and forms, or 1/5 of the narrowest dimension between sides of forms — whichever applies (Concrete Manual 12.3)
Extra mixing water needed in hot weather to hold the same slumpAbout 8 pounds (1 gallon) of water per cubic yard for each 10°F rise in concrete temperature (Concrete Manual 19.1)
Slump loss with rising concrete temperatureSlump decreases roughly 1/2 to 1 inch for each 10°F rise in concrete temperature (Concrete Manual 2.2)
Frontage area increase for allowable building areaIf = [F/P – 0.25] × W/30, applicable only where not less than 25 percent of the building perimeter is on a public way or open space (IBC 506.3.1, Equation 5-5)
Stories value in the allowable-area equation for multistory single-occupancy buildingsSa = actual number of stories above grade plane, not to exceed three for NFPA 13 sprinklered buildings (not to exceed four only for NFPA 13R per 903.3.1.2); no individual story may exceed the area determined using Sa = 1 (IBC 506.2.3, Equation 5-2)
Cripple wall bracing length adjustmentTabulated bracing length (same method as wall above) × 1.15; any gypsum-board-omission adjustment is applied in addition to the 1.15 increase (IRC R602.10.10)
Effect of specimen length-to-diameter ratio on indicated compressive strengthStandard 6 × 12 in. cylinder (L/D = 2.0) = 100 percent; a 6-in.-diameter specimen 9 in. long indicates about 104 percent; correction factors for L/D less than 2.0 are applied for direct comparison (Concrete Manual 3.3; ASTM C39, C42)
Splitting tensile test result versus direct tensile strengthTensile strength indicated by the splitting tensile test may be as much as 150 percent of the direct tensile strength (Concrete Manual 3.5)
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