Georgia Residential Basic Contractor Exam

Georgia Residential Basic Contractor Exam — 8 questions (10%)

Key Concepts

Footing size and minimum dimensions - Rule-of-thumb for residential footings on average soil: footing width = twice the wall thickness; footing depth = thickness of the wall or a minimum of 6" (Modern Masonry, Ch. 15, Sec. 15.2.1; also Page 312). Carpentry and Building Construction (Page 257) states the same width rule — the footing projects one-half the wall thickness on each side. - Prescriptive footings (Contractor's Guide to Quality Concrete Construction, Page 47, Table 4.1, adapted from 2015 IBC Table 1809.7): one floor of light-frame = 12" wide, 6" thick; two floors = 15" wide, 6" thick; three floors = 18" wide, 8" thick. - Stepped footings on sloping grade: certain codes specify a maximum of 8" per step (Modern Masonry, Ch. 15, Sec. 15.2.1; Page 312). With concrete block foundations, common practice uses the standard block height and length (8" × 16") for each step. - If a footing site is dug **too deep, never backfill with soil — fill with…

Key Concepts

Mixture components and proportioning - Concrete is cement + coarse aggregate + fine aggregate + water; if coarse aggregate is missing, the material is mortar or grout (Carpentry and Building Construction (C&BC), Section 8.1). Hydration is the chemical reaction between water and cement that generates heat and hardens the concrete — concrete does not "dry out" (C&BC, Ch. 8 — Hydration). - Ready-mix is ordered by bags of cement per cubic yard. Five-bag mix is the minimum for most work; six-bag mix is commonly specified where high strength is needed or where steel reinforcement is used (C&BC, Section 8.2, p. 226). - With SCMs, w/cm = weight of water ÷ total weight of all cementitious materials (cement + fly ash + slag + silica fume). Example: 270 ÷ (425 + 125) = 0.49 (Contractor's Guide to Quality Concrete Construction (CG), p. 36). - Cement manufacture: no more than 5 percent gypsum is added to the clinker (C&BC, Ch. 8 — Portland Cement).

Key Concepts

Foundations supporting masonry - Concrete and masonry foundation walls must extend above finished grade a minimum of 4″ where masonry veneer is used and a minimum of 6″ elsewhere (IRC R404.1.1.6; Modern Masonry, p. 313). - The foundation brick ledge must be at least equal to the total thickness of the brick veneer wall assembly (Modern Masonry, p. 333, Sec. 16.1.5). Foundations must extend beneath the frost line — check with the local building official for required footing depth. - Below grade, the foundation wall receives ½″ cement parging on the exterior face, covered with bituminous waterproofing (Modern Masonry, Fig. 16-13, Sec. 16.1.5, p. 334). - Footings: place at least 12″ below grade; width generally twice the foundation wall thickness; keyway typically 3½″ wide × 1½″ deep; rebar at least 3″ above the bottom of the footing (Carpentry & Building Construction, Sec. 10.1, Table 10-1).

Key Concepts

Lumber and panel identification - Sawn lumber for load-supporting use must carry a grade mark from an accredited agency with design values certified by an accreditation body complying with DOC PS 20 (IRC R602.1.1, p. 173). - Wood structural panel sheathing must conform to DOC PS 1, DOC PS 2, or (Canada) CSA O325/O437, and be identified for grade, bond classification and performance category (IRC R602.1.8, p. 173).

Floor framing - Joist/beam/girder ends: not less than 1½ in. bearing on wood or metal, 3 in. on masonry or concrete (IRC R502.6, p. 141). - Joists lapping over a bearing support: lap not less than 3 in., nailed with a minimum of three 10d face nails (IRC R502.6.1, p. 141). - Joists exceeding nominal 2×12 need lateral support (solid blocking, bridging, or continuous 1×3 strip) at intervals not exceeding 8 ft (IRC R502.7.1, p. 141). - Where a header joist span exceeds 4 ft, both header and trimmer joists must be doubled (IRC R502.10, pp. 141–143). - Sill plate anchor bolts: maximum **6…

Georgia Residential Basic Contractor Exam · 8 questions (10%)

Key Concepts

Roof slope categories (Carpentry and Building Construction, Section 22.1) - Flat: below 2½-in-12. Low slope: between 2½-in-12 and 4-in-12. High slope: 4-in-12 or greater. - Strip shingles are installed on roofs with a slope of 4-in-12 or greater; below that, consult the shingle manufacturer's literature (Section 22.2).

Minimum slopes by covering (IRC 2018, Chapter 9) - Asphalt shingles: 2:12 or greater (R905.2.2). From 2:12 up to 4:12, double underlayment is required. - Clay and concrete tile: 2½:12 or greater (R905.3.2). - Wood shingles and wood shakes: 3:12 or greater (R905.7.2 and R905.8.2).

Underlayment - IRC Table R905.1.1(2), asphalt shingles, 2:12 up to 4:12: two layers — a 19-inch starting strip at the eave, then 36-inch-wide sheets overlapping successive sheets 19 inches. - Carpentry text, single coverage (Section 22.2 — Installing Underlayment): No. 15 felt rolled from the eave upward, top lap of at least 2 inches at horizontal joints and a 4-inch side lap at end joints.

Georgia Residential Basic Contractor Exam

Key Concepts

IRC scope and administration - The IRC applies to detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a separate means of egress (IRC §R101.2, Page 1). - Where a general requirement conflicts with a specific requirement, the specific requirement applies (§R102.1, Page 1). - Permit exemptions (§R105.2, Pages 3–4): one-story detached accessory structures with floor area not exceeding 200 sq ft; fences not over 7 feet high; retaining walls not over 4 feet; attached decks serving an exit door are not exempt. - A permit application is deemed abandoned 180 days after the date of filing unless pursued in good faith or a permit has been issued (§R105.3.2, Page 5). - An issued permit becomes invalid if work is not commenced within 180 days after issuance, or if more than 180 days pass between inspections (§R105.5, Page 5).

Key Concepts

Drywall types and materials - 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. (Carpentry & Building Construction, Ch. 32, Fire-Code Drywall) - Glass-mat gypsum board ("paperless drywall") has front and back surfaces covered by a thin fiberglass material instead of paper and is approved for shower stalls and tub/shower surrounds; green board is no longer permitted there except on ceiling surfaces. (Ch. 32, Moisture-Resistant Drywall) - Panel edges along the length are tapered so joints can be filled with compound and smoothed flush. (Ch. 32, Standard Drywall)

Fasteners and fastening - Type-S screws are for steel framing (narrow threads); Type-W screws are for wood framing (wide threads). Neither requires a pilot hole. Only screws may be used on steel framing. (Ch. 32, Drywall Fasteners; Steel Framing) - Screws attaching gypsum board to wood framing shall be Type W or Type S and shall penetrate the wood not less than 5/8 inch (15.9 mm).…

Key Concepts

Fall protection - Employees 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). The Safety text (Section 4.2.6) states OSHA requires protection "when working at levels 6' and above for most types of construction activities," and that falls cause roughly 400 of nearly 1,000 annual construction deaths (about 40%). - Guardrail top edge height: 42 inches (1.1 m) plus or minus 3 inches (8 cm) above the walking/working level — §1926.502(b)(1) (i.e., a 39–45 inch range). - 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 figure applies to midrails and intermediate members — §1926.502(b)(5). - Subpart M does not cover scaffold fall protection (that is Subpart L) — §1926.500(a)(2)(i). Scaffold fall protection is required at 10 ft.…