Tennessee BC-A, b (sm) Combined Residential/Small Commercial Contractor

Key Concepts

Scales and drawing conventions - Dimensions may be shown in engineering scale (feet and tenths of a foot) or architectural scale (feet, inches, and fractions of an inch); plans used in excavation and grading work are likely to use engineering scale (Module 22209, Section 1.0.0, Page 98). - Most utility site plans are drawn using two scales — one horizontal, one vertical. In the text's example, 1" = 40' horizontally and 1" = 10' vertically, making the horizontal scale 4 times the vertical; the text notes the horizontal scale is usually ten times the vertical (Pipe & Excavation Contracting, Page 109). - A station number shows horizontal distance in multiples of 100 feet: the figure left of…

8 questions, 8% of the exam

Key Concepts

Scope, administration and authority of the building official - The building official may render interpretations (R104.1), grant modifications for practical difficulties (R104.10) and approve alternative materials and methods (R104.11), but interpretations, policies and procedures shall not have the effect of waiving requirements specifically provided for in the code (IRC R104.1). - Permit exemptions include fences not over 7 feet high; one-story detached accessory structures only where floor area does not exceed 200 square feet; retaining walls only where not over 4 feet in height; decks only where they do not exceed 200 square feet and are not more than 30 inches above grade (IRC R105.2). - The permit application must identify…

TN BC-A,b (sm) · 5 questions (5%)

Key Concepts

Excavation safety (OSHA Subpart P) - Type A = cohesive soil with unconfined compressive strength 1.5 tsf (144 kPa) or greater; Type B = greater than 0.5 tsf but less than 1.5 tsf; Type C = 0.5 tsf or less. Soil is not Type A if fissured, subject to vibration, or previously disturbed — Subpart P, Appendix A, paragraph (b). - Ventilation or other adequate precaution is required to keep employees from exposure to flammable gas exceeding 20 percent of the lower flammable limit; atmospheric testing is required before entry into excavations greater than 4 feet deep where oxygen deficiency (below 19.5 percent) or other hazardous atmospheres could exist —…

Key Concepts

Footing size and projection. Minimum width W and thickness T per Tables R403.1(1)–(3), but not less than 12 inches in width and 6 inches in depth; footing projections P shall be not less than 2 inches and shall not exceed the thickness of the footing (IRC R403.1.1). IBC agrees: minimum depth 12 inches, minimum width 12 inches (IBC 1809.4).

Depth and frost. Exterior footings shall be placed not less than 12 inches below the undisturbed ground surface (IRC R403.1.4); deck footings, 12 inches (IRC R507.3.2). Frost protection is by extending below the frost line, Section R403.3, ASCE 32, or solid rock (R403.1.4.1). Frost-protected shallow foundations apply only where the building's monthly mean temperature is maintained at not…

Tennessee BC-A, b (sm) — 10 questions (10% of exam)

Key Concepts

Materials and cement types - Concrete is cement, coarse aggregate, fine aggregate and water; hydration is the chemical reaction when water combines with cement — it generates heat and hardens the concrete (it does not "dry out"). (Carpentry & Building Construction, Ch. 8 — Hydration) - No more than 5 percent gypsum is added to clinker during Portland cement manufacture. (C&BC, Ch. 8 — Portland Cement) - Type III (high-strength) is used where forms must be removed quickly or concrete put in service quickly (C&BC, Table 8-1); it reaches in 7 days about the strength Type I reaches in 28 days (Contractor's Guide, 4th ed., pp. 14–15).…

Key Concepts

Masonry units and materials - A solid masonry unit is "one whose cross-sectional area in every plane parallel to the bearing surface is 75% or more of its gross cross-sectional area measured in the same plane." Cored brick still counts as solid if holes are under 25% (Modern Masonry 9th ed., p. 123). - Unstabilized adobe units must average 300 psi compressive strength per ASTM C67; five samples are tested and no individual unit may be below 250 psi (IBC 2021, 2109.2.1.1). - Concrete masonry units for dry-stack masonry must comply with ASTM C90 (IBC 2021, 2114.3); construction of dry-stack masonry must comply with ASTM C946 (IBC 2021, 2114.5). Maximum allowable compressive stress for dry-stack masonry, gross…

Tennessee BC-A, b (sm) — 12 questions (12%)

Key Concepts

Lumber sizing. Dimensions of lumber on drawings are deemed nominal unless specifically designated as actual (IBC 2301.2). Computations to determine required member sizes shall be based on net dimensions (actual sizes), not nominal (IBC 2304.2).

Studs, plates, corners. Studs shall be a minimum No. 3, standard or stud grade (IRC R602.2). Not less than three studs at each corner of an exterior wall; exception permits two with wood spacers or backup cleats (IBC 2308.5.2). End joints in double top plates shall be offset not less than 48 inches and nailed per Table 2304.10.2 (IBC 2308.5.3.2); under the IRC, end joints in top plates shall be offset **not less than…

Key Concepts

Window types and parts - A casement window has a side-hinged sash that swings inward or outward; its advantage over the double-hung type is that the entire window area can be opened for ventilation (Windows & Skylights chapter, Types of Windows section). - A muntin is a vertical or horizontal piece within a sash that holds a pane of glass; a mullion strip is a vertical piece separating combined window units (Windows & Skylights chapter, Double-Hung Windows section). NCCER Module 27109-13 trade terms also define rail (horizontal member of a sash or panel door), stile (vertical member), sash (part of the window that holds the glass), and light and glazing (material such as glass or plastic used…

Key Concepts

Framing and support - Wood supports for lath, gypsum board or gypsum panel products, and wood stripping or furring, shall be not less than 2 inches nominal thickness in the least dimension; exception — furring strips over solid backing not less than 1 inch by 2 inches nominal (IBC 2015/2021 §2504.1.1; IRC R702.3.2, which adds "or framing spaced not more than 24 inches on center"). - Panel limitations: 3/8″ panels are for framing centers up to 16″; 1/2″ and 5/8″ panels up to 24″ (Gypsum Construction Handbook 7th ed., Page 3, item 3). Application over 3/4″ wood furring applied across framing is not recommended; furring should be 2 × 2 minimum, but may be 1 × 3…

TN BC-A, b (sm) · 6 questions (6% of exam)

Key Concepts

Scope and referenced standards (IBC Chapter 22) - The steel chapter governs the quality, design, fabrication and erection of steel construction (IBC 2021 §2201.1). - Structural steel: design, fabrication and erection per AISC 360 (IBC §2205.1). - Seismic: structures in SDC D, E or F → designed and detailed per AISC 341 (§2205.2.1.2). Exception in SDC B or C: where the R for "Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems" is used, the system may be designed and detailed per AISC 360 and need not follow AISC 341 (§2205.2.1.1). - Composite steel/concrete: AISC 360 and ACI 318, excluding ACI 318 Chapter 14…

TN BC-A, b (sm) · 10 questions (10%)

Key Concepts

Roof coverings and minimum slopes - Asphalt shingles shall be used only on roof slopes of 2:12 or greater; slopes from 2:12 up to 4:12 require double underlayment application (IRC 2021/2018, R905.2.2). - Standard application of asphalt shingles generally covers slopes of 4 in 12 through 21 in 12; slopes as flat as 2 in 12 or steeper than 21 in 12 require special application procedures (Roofing Construction & Estimating, Ch. 4). - Strip shingles are installed on roofs with a slope of 4-in-12 or greater — the "high slope" category; lower slopes require the manufacturer's literature (Carpentry and Building Construction, Sec. 22.1 Roof Slope; Sec. 22.2). - Slate:…

Tennessee BC-A, b (sm) Combined Residential/Small Commercial Contractor — 3 questions (3%)

Key Concepts

Fixture counts (IBC 2021) - To determine the occupant load of each sex, divide the total occupant load in half; apply the ratios of Table 2902.1 to each sex. Fractional results are rounded up to the next whole number; for multiple occupancies, fractions for each occupancy are first summed, then rounded up (Sec. 2902.1.1). - Exception 1: the total occupant load is not required to be divided in half where approved statistical data indicates a distribution of the sexes other than 50 percent of each sex (Sec. 2902.1.1, Exc. 1). - Exception 2: where multiple-user facilities serve all genders, the minimum fixture count is calculated…

Key Concepts

Equipment sizing. Heating and cooling equipment and appliances shall be sized in accordance with ACCA Manual S or other approved sizing methodologies, based on building loads calculated in accordance with ACCA Manual J or other approved heating and cooling calculation methodologies (Section M1401.3, IRC Page 14-1).

Support and clearance. Equipment supported from the ground shall be level and firmly supported on a concrete slab or other approved material extending not less than 3 inches above the adjoining ground; appliances suspended from the floor shall have not less than 6 inches clearance from the ground (Section M1305.1.3.1, Page 13-2). A level working space not less than 30 inches deep and 30 inches wide is required in front of…

Key Concepts

Emergency and standby power (IBC Chapter 27) - Stationary emergency and standby generators required by the code must be listed in accordance with UL 2200 (IBC 2702.1.1). - Fuel lines supplying a generator set inside a high-rise must be separated from other areas by a UL 1489-tested pipe-protection system or an assembly rated not less than 2 hours; where the building is sprinklered throughout per Section 903.3.1.1, the required rating is reduced to 1 hour (IBC 2702.1.2). - Load transfer: emergency systems must automatically provide secondary power within 10 seconds; standby systems within 60 seconds, unless specified otherwise (IBC 2702.1.4). - Load duration: minimum 2 hours without refueling or recharging, unless specified otherwise (IBC 2702.1.5). - Emergency…

Key Concepts

Fall protection (Subpart M) - Each employee on a walking/working surface with an unprotected side or edge 6 feet or more above a lower level must be protected by guardrail, safety net, or personal fall arrest systems — §1926.501(b)(1). The same 6-foot trigger applies to residential construction — §1926.501(b)(13). - Guardrail top edge height: 42 inches (1.1 m) plus or minus 3 inches above the walking/working level — §1926.502(b)(1) (i.e., the 39–45 inch range of §1926.502). - Top rails must withstand, without failure, at least 200 pounds (890 N) applied within 2 inches of the top edge in any outward or downward direction — §1926.502(b)(3). The 150-pound requirement applies to midrails and intermediate members — §1926.502(b)(5). -…

Key Concepts

Water-resistive barrier / house wrap - House wrap is installed over the plywood or OSB sheathing. A 6" to 12" lap at every horizontal joint is required; at corners, a 3' lap from both sides is usually recommended; all window and door openings must be wrapped to prevent water penetration (Residential Home Builder Study Guide, Ch. 10 — Module 27204-13, Section 2.0.0). - IRC 2018 R703.2: one layer of No. 15 asphalt felt complying with ASTM D226 Type I, or other approved WRB, applied over studs or sheathing of all exterior walls. No. 15 felt is applied horizontally with the upper layer lapped over the lower not less than 2 inches; where joints occur, felt is lapped…