Tennessee BC-A Residential Contractor

Tennessee BC-A Residential Contractor Exam Study Brief

Key Concepts

Footing Design and Sizing - Footing width must be at least twice the foundation wall thickness for most residential applications - Footing depth must extend below the frost line — in Tennessee, typically 18–24 inches minimum below finished grade - Footing width is determined by the load it carries divided by the soil's allowable bearing capacity - The standard rule: footing projection beyond the wall face on each side = footing thickness (equal overhang both sides)

Footing Types - Continuous (strip) footing: runs the full length of a load-bearing wall; most common in residential construction - Stepped footing: used on sloped sites; horizontal steps must not exceed 2/3 of the horizontal distance; each step must be a full footing depth - Pier/isolated footing: supports individual columns or posts; sized for point loads - Monolithic (thickened-edge slab): footing and slab poured in one operation; common in slab-on-grade construction in warmer Tennessee regions

Key Concepts

Mixture Components & Proportioning

• Cement types: Type I (general use), Type II (moderate sulfate resistance), Type III (high early strength), Type IV (low heat of hydration), Type V (high sulfate resistance)
• Water-cement (w/c) ratio: Lower ratio = higher strength. Residential foundations typically use 0.45–0.50 w/c ratio. Never add water to increase workability without reducing strength
• Aggregates: Fine (sand) and coarse (gravel/crushed stone). Max aggregate size should not exceed 1/3 slab thickness, 3/4 of minimum rebar spacing, or 1/5 of the narrowest form dimension
• Admixtures: Air-entraining (freeze/thaw resistance), water reducers (plasticizers), accelerators (cold weather), retarders (hot weather), fly ash (pozzolan supplement)

Field Control Testing

• Slump test (ASTM C143): Measures workability. Standard residential mix = 3–4 inches. Pump mixes up to 5 inches
• Air content (ASTM C231): Target 5–7% entrained air for freeze/thaw exposure
• Compressive strength cylinders (ASTM C39): 6×12-inch cylinders cured and tested at 28 days; minimum 3,000 psi typical for residential
• Unit weight/yield (ASTM C138): Confirms volume delivered matches design mix

Key Concepts

Mortar Types, Proportions & Mixing

• Type S – High strength, best for below-grade and exterior applications (most common in residential). Ratio: 1 part portland cement, ½ part lime, 4½ parts sand.
• Type N – Medium strength, general above-grade exterior use. Ratio: 1 part portland, 1 part lime, 6 parts sand.
• Type M – Highest compressive strength, used for foundations and retaining walls. Ratio: 1 part portland, ¼ part lime, 3 parts sand.
• Type O – Low strength, interior non-load-bearing only.
• Never retemper mortar more than 2.5 hours after initial mixing. Discard stiffened mortar that cannot be retempered.

Brick & CMU Classifications

• Face brick grades: SW (severe weathering), MW (moderate weathering), NW (negligible weathering).
• CMU grades: Grade N – exterior/exposed use; Grade S – above grade, protected applications.
• CMU types: hollow, solid, special shapes (lintel, bond beam, pilaster).

Key Concepts

Wood Framing Systems

• Platform framing: Each story is framed independently on a platform; most common modern method. Studs run one story tall.
• Balloon framing: Studs run continuously from sill to top plate (two stories); floor joists hang from a ribbon board let into the studs. Fire blocking required.
• Post-and-beam: Heavy timber members spaced farther apart; structural loads carried by posts and beams rather than stud walls.

Floor Framing Components

• Sill plate: Pressure-treated lumber anchored to foundation with anchor bolts (IRC R403.1.6 — bolts max 6' O.C., within 12" of ends).
• Girders/Beams: Support joists mid-span; sized by span tables.
• Joists: Sized per IRC Table R802.4 span tables based on species, grade, spacing (12", 16", 24" O.C.).
• Bridging: Solid blocking or cross-bridging; IRC R502.7 requires bridging at max 8' intervals for joists with depth-to-thickness ratio >6.
• Subfloor: Typically 3/4" tongue-and-groove OSB or plywood; panels staggered, glued and nailed.

Key Concepts

Roof Measurement & Area Calculation

• Roof area = plan (horizontal) area × slope factor. Slope factor converts flat footprint to actual sloped surface area.
• Common slope factors: 4/12 = 1.054 | 6/12 = 1.118 | 8/12 = 1.202 | 12/12 = 1.414
• Pitch = rise ÷ span (total width). Slope = rise per 12" of run. These are not interchangeable terms.
• Ridge, hip, and valley lengths are calculated using the Pythagorean theorem. Hip/valley rafter length uses unit diagonal of 17" (instead of 12") per foot of run.

Asphalt Shingles

• Rated by weight per square (100 sq ft) and wind/impact resistance class (Class 4 = highest impact).
• Standard 3-tab shingles: 5" exposure. Architectural/laminated shingles: typically 5½"–6" exposure.
• Installation: minimum 2 fasteners per strip in low wind; 4–6 nails per shingle per manufacturer and wind zone. Nails must penetrate decking minimum ¾" or through OSB/plywood.
• Starter course required at eaves and rakes; offset joints minimum 6" from course below.

Tennessee BC-A Residential Contractor Exam Study Brief

Key Concepts

Building Permits & Inspections

• Permits are required before beginning construction on new residential structures, additions, and most renovations.
• The IRC (International Residential Code) governs one- and two-family dwellings and townhouses not more than three stories above grade.
• Inspections typically occur at: foundation/footing, framing, rough-in (mechanical/electrical/plumbing), insulation, and final.
• A Certificate of Occupancy (CO) is issued only after passing final inspection.

IRC Scope & Administration

• IRC Chapter 1 covers administration: permits, inspections, fees, violations, and stop-work orders.
• The IRC applies to one- and two-family dwellings only; commercial structures fall under the IBC.
• Amendments adopted by Tennessee may modify base IRC provisions — always apply the most restrictive requirement.

Study Brief (15 Questions / 15% of Exam)

Key Concepts

Drywall Panel Types

• Standard (Type X / Type W): General interior use; 1/2" most common for walls, 5/8" for ceilings
• Fire-code (Type X): 5/8" thick; required in garages adjacent to living space, stairwells, and fire-rated assemblies; glass fibers added to core
• Moisture-resistant (MR/greenboard): Use in bathrooms and kitchens — not a substitute for cement board in tile-wet areas
• Flexible drywall: 1/4" panels; used for curved surfaces and radius walls

Drywall Finishing Levels (GA-214 Standard)

Key Concepts

Fall Protection (29 CFR 1926 Subpart M)

• Trigger height for residential construction: 6 feet. Any worker exposed to a fall of 6 feet or more to a lower level must be protected by guardrail systems, safety net systems, or personal fall arrest systems.
• Covers all residential construction activities including roofing, floor framing, and wall openings.
• Covers and guardrails are required for floor holes/openings that workers could fall through.

Scaffold Safety (29 CFR 1926 Subpart L)

• Scaffolds must be erected, moved, dismantled, or altered only under the supervision of a competent person.
• Minimum platform width: 18 inches for most scaffold platforms.
• Scaffolds must support 4x the maximum intended load.
• Guardrails required on open sides/ends of scaffold platforms 10 feet or more above the ground.
• Access must be provided; cross-bracing alone does not serve as safe access.