Tennessee BC-B Commercial Contractor

Key Concepts

Civil drawings and scales - 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. - A profile is the side view, parallel to the center line, depicting heights, depths, and slopes; a cross section is a cutaway view perpendicular to the longitudinal axis or center line — Module 22201, Trade Terms, Pages 361 and 401. - Besides the typical cross-sections, a package may include cross-section sheets showing natural ground and finish grade every 50 feet or other established distance — *Module 22209, Section…

Key Concepts

Administration. A permit application for proposed work is deemed abandoned 180 days after the date of filing unless the application has been pursued in good faith or a permit has been issued (IBC 105.3.2).

Occupancy classification. A building or tenant space used for assembly purposes with an occupant load of less than 50 persons is classified as Group B (IBC 303.1.1).

Definitions (IBC 202). Fire wall: a fire-resistance-rated wall having protected openings that restricts the spread of fire and extends continuously from the foundation to or through the roof, with sufficient structural stability to allow collapse on either side without collapse of the wall. Area, building: the area within surrounding exterior walls, or exterior walls and fire…

Key Concepts

Excavation safety and the competent person - Never enter an excavation without the approval of the OSHA-approved competent person on site; the competent person inspects the excavation daily for changes caused by rain, frost, or severe vibration from nearby heavy equipment (Module 22210-13, Section 1.4.0; Module 08209, Section 1.1.0). - Keep excavated soil (spoil) at least two feet from the edge of the excavation, and keep equipment back from the edge to prevent cave-ins (Module 22210-13, Section 1.4.0). - Ladders or ramps used as exits must be located every 25 feet in any trench over 4 feet deep (Module 08209, Section 1.1.0). - A trench is an excavation where depth is greater than width and the width…

Key Concepts

Presumptive load-bearing values (IBC 2021, Table 1806.2). Values are tabulated by class of material. Mud, organic silt, organic clays, peat or unprepared fill shall not be assumed to have a presumptive load-bearing capacity unless data are submitted (Section 1806.2). Per Section 1806.1, tabulated vertical foundation pressure and lateral bearing pressure may be increased by one-third where used with the alternative ASD load combinations of Section 1605.2 that include wind or earthquake loads.

Lateral load resistance. Lateral bearing pressures may be increased by the tabular value for each additional foot of depth, to a value not greater than 15 times the tabular value (Section 1806.3.3). Isolated poles for flagpoles or signs (and poles supporting buildings not adversely affected…

Key Concepts

Minimum dimensions and strengths (IBC) - Concrete floor slabs supported directly on the ground: not less than 3½ in. (89 mm), with a 6-mil polyethylene vapor retarder, joints lapped not less than 6 in., between base course/subgrade and slab (2021 IBC 1907.1). - Plain concrete footings may be reduced to 6 in. thick for Group R-3 and other occupancies less than two stories above grade plane of light-frame construction, provided the footing does not extend more than 4 in. on either side of the supported wall (IBC 1906.1). - Group R-2 and R-3 not more than three stories above grade plane: f′c not less than 3,000 psi for basement walls, foundation walls, exterior walls and other vertical…

Key Concepts

Materials and standards (IBC 2021, Ch. 21) - Adhered manufactured stone masonry veneer units conform to ASTM C1670 (§2103.1). Structural clay tile used nonstructurally for fireproofing structural members and as wall furring is exempt from the compressive strength specifications, but its fire-resistance rating is determined per ASTM E119 or UL 263 and must comply with Table 705.5 (§2103.1 Exception). - Mortar conforms to Articles 2.1 and 2.6 A of TMS 602 (§2103.2.1); grout conforms to Article 2.2 of TMS 602 (§2103.3). - Surface-bonding mortar complies with ASTM C887; the surface bonding of concrete masonry units (the application method) complies with ASTM C946 (§2103.2.2). - Mortar for adhered masonry veneer: ASTM C270 Type N or S, or ANSI…

Key Concepts

Wall framing — studs, plates, openings - Not less than three studs shall be installed at each corner of an exterior wall; an exception allows two studs where wood spacers or backup cleats serve as adequate backing for facing materials (IBC 2021, Section 2308.5.2). - In exterior walls and bearing partitions, a wood stud shall not be cut or notched in excess of 25 percent of its depth (IBC 2021, Section 2308.5.9). Studs in nonbearing partitions may be notched to a depth not exceeding 40 percent of a single stud width; 60 percent is the maximum bored-hole diameter, with doubling required in bearing walls above 40 percent (IRC 2018, Section R602.6, Item 1 and Figure R602.6(2)). -…

Key Concepts

Window and door components (reference-text chapters) - Casement windows have a side-hinged sash that swings inward or outward; unlike a double-hung, the entire window area can be opened for ventilation (Windows & Skylights chapter, Types of Windows). - 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). - U-values are like R-values reversed: a lower U-value means less heat loss or gain and greater insulating performance. The NFRC uses U-values with other metrics to rate window energy efficiency (Windows & Skylights chapter, Energy Efficiency – Ratings). - Solid-core construction (wood strips, particleboard,…

Key Concepts

Panel types (Carpentry & Building Construction, Ch. 32, Fire-Code Drywall section) - Type‑X fire‑code drywall is 5/8″ thick and contains glass fibers that prevent it from crumbling in extreme heat. Type‑C is even more fire resistant and contains vermiculite. - Specialty panels: foil‑back (aluminum foil vapor retarder on back), flexible (for curved walls), sound‑resistant (layer of sound‑absorbing polymers). Most common thickness is 1/2″.

Framing, furring and support limits - 3/8″ panels are designed for framing centers up to 16″; 1/2″ and 5/8″ panels for centers up to 24″ (Gypsum Construction Handbook 7th ed., p. 3, Gypsum Panel Limitations item 3). - Application is not recommended over 3/4″ wood furring applied across framing (hammer impact loosens driven nails).…

Key Concepts

Pre-erection and site readiness - The owner's designated representative for design (ODRD) is responsible for job planning and works with the ODRC, who answers to the owner for overall construction, planning, quality and completion (usually the GC or on-site construction manager). (Pearson CBC Study Guide 2024, Structural Ironworking Two — Section 2.3.1) - A competent person must determine the erection sequence before pick lists (also called hanging lists) can be completed. (Sections 2.3.2 and 2.3.3) - In most cases the fabricator furnishes all fastener materials needed to assemble and erect the delivered components, and they should not already be installed in those components; fasteners must be stored protected from the elements. (Sections 2.4.1 and 2.4.2) - Before…

Key Concepts

Roof coverings and minimum slopes - Asphalt shingles on commercial buildings: permitted only on slopes of 2:12 or greater; slopes from 2:12 to less than 4:12 require double underlayment (IBC 2021, §1507.2.2). - Strip (three-tab) shingles are installed on roofs with a slope of 4-in-12 or greater; 4-in-12 and greater is the "high slope" category. Lower slopes require the manufacturer's special instructions (Carpentry & Building Construction, §22.1 Roof Slope; §22.2 Installation Issues). - Asphalt shingles are generally installed on slopes 4 in 12 through 21 in 12 by standard methods; slopes as flat as 2 in 12 or steeper than 21 in 12 require special application procedures (Roofing Construction & Estimating, Ch. 4). - Clay/concrete tile is…

Key Concepts

Fixture counts (IBC 2021, Chapter 29) - Fixtures are provided in the minimum number shown in Table 2902.1 based on actual use of the building or space; uses not shown are considered individually by the code official (2902.1). - To determine the occupant load of each sex, the total occupant load is divided in half, then the ratios are applied. Fractional numbers are rounded up to the next whole number; for calculations involving multiple occupancies, the fractional numbers for each occupancy are first summed and then rounded up (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…

Key Concepts

Equipment sizing and installation - 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 (IRC, Page 14-1, Section M1401.3). - Equipment and appliances 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 clearance of not less than 6 inches from the ground (IRC, Page 13-2, Section M1305.1.3.1). - A level working space **not less than 30 inches deep and 30 inches…

Key Concepts

Emergency and standby power (IBC 2021, Chapter 27) - Load transfer: Emergency power systems shall automatically provide secondary power within 10 seconds after primary power is lost; standby power systems within 60 seconds, unless specified otherwise in the code (IBC 2702.1.4). - Load duration: Emergency and standby power systems shall provide the required power for a minimum duration of 2 hours without being refueled or recharged, unless specified otherwise (IBC 2702.1.5). - Longer durations where specified: in-building 2-way emergency responder communication coverage — 100-percent system operation capacity for not less than 12 hours (2702.2.3); auxiliary inflation systems in permanent membrane structures — not less than 4 hours (2702.2.15); special purpose horizontal sliding, accordion or folding doors —…

Key Concepts

Fall protection - 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 systems, safety net systems, or personal fall arrest systems — §1926.501(b)(1). - The same 6-foot trigger applies to employees engaged in residential construction; protection may be guardrail systems, scaffolding, a safety net system, or a personal fall arrest system — §1926.501(b)(13). - Guardrail top rail: capable of withstanding, without failure, a force of at least 200 pounds (890 N) applied within 2 inches of the top edge, in any outward or downward direction, at any point along the top edge — §1926.502(b)(3). Midrails and intermediate members: 150 pounds —…