Tennessee BC-A Residential Contractor

Key Concepts

Load path and drainage. Construction must provide a complete load path transferring loads from point of origin through load-resisting elements to the foundation (IRC R301.1). Lots must be graded to drain surface water away from foundation walls, with the grade falling not fewer than 6 inches within the first 10 feet (IRC R401.3).

Soil classification and bearing. For compaction, soils fall into granular (sands, gravels — best compacted by vibration) and cohesive (silts, clays — best compacted by impact force or sustained pressure) (Contractor's Guide, p. 44). On fill sites, both the quality of the fill and the degree of compaction must be determined before foundation work starts (p. 44). Presumptive load-bearing values, IRC Table R401.4.1: crystalline bedrock 12,000 psf; sedimentary/foliated rock 4,000 psf; sandy gravel and/or gravel (GW, GP) 3,000 psf; sand, silty sand, clayey sand, silty/clayey gravel (SW, SP, SM, SC, GM, GC) 2,000 psf; clay, sandy clay, silty clay, clayey silt, silt, sandy silt (CL, ML, MH, CH) 1,500 psf. Note b: where the building official determines in-place soils…

Key Concepts

Air entrainment (heavily tested). The most important benefit of air entrainment is improved resistance to damage from freezing-and-thawing cycles and deicing chemicals; the microscopic entrained voids relieve internal pressure from water expansion and ice formation (Contractor's Guide, p. 11). All concrete exposed to freezing weather while in service should be air entrained (Contractor's Guide, p. 181). Codes may require air-entrained concrete where concrete is exposed to moderate or severe weathering — sidewalks, exposed basement walls, garage slabs (Carpentry, p. 226). IRC minimum total air content for freezing/thawing exposure is 5% (Modern Masonry, p. 385); IRC Table R402.2, Note d sets the range at not less than 5% nor more than 7%. For scaling resistance, roughly 5 to 8 percent (Contractor's Guide, pp. 192, 199); Table 2.2 gives 4-1/2% to 7-1/2% by aggregate size (6% for 3/4 in.), field tolerance ±1-1/2%. Interior floors receiving a hard-trowel finish: total air not over 3% (Contractor's Guide, pp. 16, 21).

Tennessee BC-A Residential Contractor · 7 questions (7% of exam)

Key Concepts

Foundation heights and anchorage - Concrete and masonry foundation walls shall extend above finished grade not less than 4 inches where masonry veneer is used and not less than 6 inches elsewhere (IRC R404.1.6; also cited as R404.1.1.6, Modern Masonry p. 313). - Wood sill plates shall be anchored with minimum 1/2-inch-diameter anchor bolts spaced not greater than 6 feet on center, extending not less than 7 inches into concrete or grouted cells of concrete masonry units. Not fewer than two bolts per plate section, with one bolt not more than 12 inches or less than seven bolt diameters from each end (IRC R403.1.6). The 15-inch embedment belongs to cold-formed steel connections (R603.3.1), not wood sill plates. - Masonry used in foundation systems requires a minimum specified compressive strength of 1,500 psi (IRC R402.4). - Masonry foundation walls enclosing basement space require not less than 3/8-inch Portland cement parging applied to the exterior, then dampproofed (bituminous coating; 3 lb/sq yd acrylic modified…

Key Concepts

Framing systems - Balloon frame: studs run continuously from the sill plate to the top plate of the second floor; second-floor joists bear on 1×4 ribbons ("ribands") cut into the inside edges of the studs (Carpentry & Building Construction, Sec. 14.1, pp. 370–371). - Platform frame: studs are only long enough to form one story; each level is built separately (pp. 370–372). - Dead load = total weight of the building including the structural frame and anything permanently attached (wall coverings). Live load = weight not permanently attached (furniture, people), determined by building use (Sec. 14.1, p. 383). - Shear wall: resists severe forces that tend to separate sheathing from framing / lateral (sideways) forces. Sheathing must be nailed to all studs, blocking, and sills 3" OC with 8d common or galvanized box nails (Sec. 16.1, p. 437; p. 378).

Key Concepts

Slope categories and minimum slopes - Three code slope categories: flat is below 2½-in-12; low slope is between 2¼-in-12 and 4-in-12; high slope is 4-in-12 or greater. Most shingled roofs are high-slope (Carpentry, Sec. 22.1). - Strip shingles are installed on roofs of 4-in-12 or greater; for lower slopes consult the manufacturer's literature (Carpentry, Secs. 22.1, 22.2). - Asphalt shingles: minimum 2:12; slopes from 2:12 up to 4:12 require double underlayment (IRC R905.2.2). Clay and concrete tile: 2½:12 (IRC R905.3.2). Standing-seam metal: ¼:12 (IRC R905.10.2, Item 3). - Reroofing need not meet the ¼:12 minimum design slope where the roof provides positive drainage (IRC R908.1, Exception 1).

Underlayment - Single coverage: No. 15 felt from the eave line upward, 2" minimum top lap at horizontal joints, 4" side lap at end joints (Carpentry, Sec. 22.2). Double coverage: 19" head laps, 17" exposures (Sec. 22.2). - 2:12–4:12 asphalt: two layers — 19" starter strip at eaves, then 36"-wide sheets lapping 19"; end laps 4", offset 6 feet (IRC Table R905.1.1(2)). - Where wind…

Key Concepts

Plan reading and drawing types - A plan view is a top or "bird's-eye" view; you can see width, length and location, but not height (Carpentry and Building Construction, Section 2.3, Page 49–50). In engineering plans, a profile view shows a horizontal cut-away along the alignment, revealing elevations, grades and depths (Pipe and Excavation Contracting, Page 105). - Schedules are charts in the plan set that provide rough-opening sizes for windows and doors (Carpentry and Building Construction, Section 16.2, Page 440). A room-finish schedule lists materials and finishes for floors, walls and ceilings in each room (Section 2.3, Page 57). - Window callouts give width first, height second, followed by lites and style; "24½" x 24", 2 lites D.H." = a double-hung unit with two panes, glass 24½" wide by 24" high (Section 20.2, Page 585). - HDR = Header (HDW = Hardware) (Ready Reference Appendix, Page 1024). DFL = Douglas fir-larch (IRC, Table R502.3.1(2)). - At ¼" = 1'-0", each quarter inch on the drawing equals one foot of building (IRC,…

Key Concepts

Drywall panels, fire-rated assemblies and estimating - UL Design U305 (1-hr wood): wood 2×4 studs at 16″ o.c., 5/8″ Firecode core panels each side, 1-7/8″ cement-coated nails 7″ o.c.; insulation is optional (Ch. 10 — One-Hour Rating, UL Design U305). - UL Design U419 (1-hr steel): studs 362S125-18 minimum at 24″ o.c., 5/8″ Firecode core each side, Type S screws 8″ o.c.; insulation optional (Ch. 10 — One-Hour Rating, UL Design U419). - Two-hour steel (U411, U412 or U419): panels vertical or horizontal with joints of the face layer staggered over joints of the base layer (Ch. 10 — Two-Hour Rating). - Fire test Note 5: in fire-rated non-load-bearing partitions, steel studs should not be attached to floor and ceiling runners (Ch. 10 — Fire and Sound Tests, Notes). - IIC rates a floor-ceiling assembly's effectiveness in retarding impact sound — tested per ASTM E492, rated per ASTM E989 (Ch. 10 — Fire and Sound Tests). - Interior non-load-bearing partitions are typically designed for 5 psf lateral load (Ch. 10 — Structural…

Key Concepts

Fall protection (Subpart M) - Fall protection is required at 6 feet or more above a lower level on walking/working surfaces with unprotected sides or edges — §1926.501(b)(1) — and for residential construction at 6 feet or more — §1926.501(b)(13). - Guardrail top rails: 42 inches ± 3 inches above the walking/working level — §1926.502(b)(1) (i.e., 39–45 inches). Top rails must withstand 200 pounds applied within 2 inches of the top edge in any outward or downward direction — §1926.502(b)(3); 150 pounds applies to midrails — §1926.502(b)(5). - Personal fall arrest: no free fall more than 6 feet, nor contact with any lower level — §1926.502(d)(16)(iii). Anchorages must support 5,000 pounds per employee attached, or be designed under a qualified person's supervision with a safety factor of at least two — §1926.502(d)(15). - Hole covers in roadways/vehicular aisles: at least twice the maximum axle load of the largest vehicle expected to cross — §1926.502(i)(1). - Safety nets required when workplaces are more than 25 feet above ground/water where ladders, scaffolds, catch platforms,…