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

Key Concepts

Scope and applicability - IBC applies to construction, alteration, use, occupancy, maintenance and demolition of every building or structure (IBC 101.2). Exception: detached one- and two-family dwellings and townhouses not more than three stories above grade plane with a separate means of egress, and their accessory structures not more than three stories above grade plane, may comply with the IBC or the IRC (IBC 101.2; IRC R101.2). - Appendix provisions do not apply unless specifically adopted (IBC 101.2.1). - Where provisions of the code conflict with referenced codes and standards, the provisions of this code apply (IBC 102.4.1). The "most restrictive governs" rule is for conflicts between different sections of the code (IBC 102.1). - A building not previously occupied or used for its intended purpose must comply with the IBC or IRC for new construction, or with any current permit for such occupancy (IBC 102.6.1). Legal occupancy of a previously occupied building may continue (IBC 102.6.2; IRC R102.7 — except as covered by the IRC, the International Property Maintenance Code or International Fire Code, or as deemed necessary by the building official).

Permits - Application must: identify/describe the work; describe the land; indicate use and occupancy; be accompanied by construction documents; state the valuation of the proposed work; be signed by the applicant (IBC 105.3). - Application deemed abandoned 180 days after filing; extensions not exceeding 90 days each (IBC 105.3.2). IRC R105.3.2: abandoned after 180 days; extensions of not more than 180 days each. - Permit becomes invalid unless work is commenced within 180 days after issuance, or if suspended/abandoned for 180 days; extensions in writing for periods not more than 180 days each (IBC 105.5). IRC R105.5 also voids a permit if more than 180 days pass between inspections. - Suspension/revocation grounds: permit issued in error, on incorrect/inaccurate/incomplete information, or in violation of any ordinance, regulation or code provision (IBC 105.6). - A permit is not approval of a violation; the building official may prevent occupancy or use of a structure in violation (IBC 105.4). - Annual permit may be issued to a person/firm…

Key Concepts

Egress capacity and exit count - Stairway capacity = occupant load × 0.3 inch per occupant; 0.2 inch applies only where the building is sprinklered and has an emergency voice/alarm communication system (IBC 1005.3.1). Other egress components use 0.2 inch, or 0.15 inch sprinklered (1005.3.2). - Three exits/exit access doorways for occupant load 501–1,000; four where over 1,000 (1006.2.1.1). - Exit separation: not less than one-half the maximum overall diagonal (1007.1.1); Exception 2 reduces to one-third where sprinklered per 903.3.1.1 or 903.3.1.2. - Increased occupant load: not to exceed one occupant per 7 square feet of occupiable floor space (1004.5.1). - Dead-end corridors: not more than 20 feet (1020.4); the 50-foot allowance is only for the listed exceptions (I-3 Conditions 2, 3, 4; B, E, F, I-1, M, R-1, R-2, S, U fully sprinklered per 903.3.1.1). - Horizontal exits: general limit one-half of required exits (1026.1); two-thirds in Group I-2 (Exception 1); 100 percent in I-3 (Exception 2). - Exit passageway width: 44 inches minimum, except 36 inches where serving an occupant load of less than 50 (1024.2).

Stairs, guards, doors - Riser 7 inches maximum (4 inches minimum), rectangular tread 11 inches minimum (IBC 1011.5.2). Flight vertical rise not greater than 12 feet between floors or landings (1011.8). One stairway to the roof in buildings four or more stories above grade plane unless roof slope is steeper than 4:12 (1011.12). Exterior exit stairways permitted for buildings not exceeding six stories above grade plane, not high-rise, not Group I-2 (1027.2). - Guards where the walking surface is more than 30 inches above the floor/grade within 36 inches horizontally (1015.2). - Door operating devices 34 inches minimum, 48 inches maximum above finished floor (1010.1.9.2). - Electrical rooms over 6 feet wide with equipment rated 1,200 amperes or more containing overcurrent/switching/control devices: panic or fire exit hardware, doors swing with egress travel (1010.1.10). - Turnstiles on an accessible route: 36 inches clear at and below 34 inches, 32 inches clear between 34 and 80 inches, mechanism other than a revolving device (1010.3.1.1); the 22-inch figure is the general turnstile…

Key Concepts

Concrete mix, strength and durability (Concrete Manual) - Minimum specified compressive strength for structural concrete is 2,500 psi (Ch. 3, §3.2, citing ACI 318 §19.2.1.1); mixes below 2,000 psi are concrete fill, not structural concrete. - Drying shrinkage is governed more by the unit water content than by the water-cement ratio (§1.4); keep total water per cubic yard as low as possible (§5.1). Calcium chloride as an accelerator increases shrinkage (§5.1). - Watertight concrete: plastic, workable, thoroughly mixed, w/c not exceeding 0.50, plus at least seven days continuous wet curing or a reliable curing compound (Ch. 23, §23.1, p. 504). - Frost resistance: 6 or 7 percent air for 3/4-inch or 1/2-inch MSA (§4.5); air-dry at least 30 days after initial moist curing before freeze-thaw exposure (§4.11, §4.12). - Sulfate exposure: Type V for severe, Type II for moderate (§4.2); of w/c and C3A, the C3A content has the greatest influence (§4.3). - Type III cement: normal 7-day strength in about 3 days, normal 28-day strength in 7 days (§3.13), but nearly the same setting times as Type I (§1.2). Do not use calcium chloride above 60°F (§3.13). - Freezing while plastic can cost up to 50 percent of strength; freezing after about 24 hours at moderate temperature, with about 500 psi developed, is probably slight damage (§3.11). Concrete held near freezing recovers under sustained curing if raised to a minimum of 60°F (§3.14). - Important load-bearing members with all surfaces exposed should not be continuously exposed above 500°F (§3.17). - First step in treating damaged concrete: classify the damage (§1.7). Site investigation is a three-way approach including existence of forces or substances that could attack the concrete (§1.8).

ICC G12 General Building Contractor (B) | 2018 IBC/IRC | 6 questions (8%)

Key Concepts

Interior wall and ceiling finish classification (IBC 803.1.2). Materials tested to ASTM E84 or UL 723 are grouped: Class A = flame spread index 0–25; Class B = flame spread index 26–75; Class C = flame spread index 76–200. All three classes carry a smoke-developed index of 0–450. There is no class above 200.

NFPA 286 room-corner alternative (IBC 803.1.1.1). Acceptance criteria include: flames shall not spread to the ceiling during the 40 kW exposure; flame shall not spread to the outer extremity of the sample; flashover shall not occur; peak heat release rate throughout the test shall not exceed 800 kW; total smoke released shall not exceed 1,000 m². Materials meeting these criteria are considered to comply with Class A.

Furring strips over rated/noncombustible construction (IBC 803.15.1). Interior finish shall be applied directly against such construction or to furring strips not exceeding 1¾ inches. Intervening spaces must be filled with inorganic/noncombustible material, filled with Class A material, or fireblocked at not greater than 8 feet in every direction.

Interior floor finish (IBC 804.2). Classified by ASTM E648 or NFPA 253: Class I, 0.45 watts/cm² or greater; Class II, 0.22 watts/cm² or greater.

Combustible decorative materials (IBC 806.2). In Groups A, B, E, I, M and R-1 and in Group R-2 dormitories, curtains, draperies and fabric hangings suspended from walls or ceilings shall not exceed 10 percent of the specific wall or ceiling area. Exceptions: 75 percent in Group A auditoriums (sprinklered per 903.3.1.1); 50 percent in Group R-2 dormitory sleeping/dwelling units (sprinklered); the 10-percent limit does not apply to window coverings.

Water-resistive barrier — IBC 1403.2. Not fewer than one layer of No. 15 asphalt felt complying with ASTM D226 for Type 1 felt, or other approved materials, attached to studs or sheathing with flashing per Section 1404.4, forming a continuous WRB behind the veneer.