Alabama Home Builder Skill Exam

Key Concepts

• Construction drawings describe the size, shape, location, and specifications of the elements of a structure; they may be called working drawings, prints, blueprints, or plans (Modern Masonry 9th ed., Section 5.1).
• Plan view is a top view ("bird's-eye view"). It shows width, length, and location of objects. It is not possible to see the height of objects in a plan view (Carpentry and Building Construction, Section 2.3).
• Floor plans are drawn as if the house were sliced horizontally at a level that would include all door and window openings; this imaginary slicing is the cutting plane. They show room arrangement/size, wall thickness, materials, and door/window types, sizes, and locations (Section 2.3).
• Site plan / plot plan shows the building lot with boundaries, contours, existing roads, utilities, trees, nearby buildings, and the driveway. The…

Key Concepts

OSHA soil classification (29 CFR 1926, Subpart P, Appendix A) - Type A: cohesive soil with unconfined compressive strength of 1.5 tsf (144 kPa) or greater; cemented soils such as caliche and hardpan are Type A [App. A(b)]. - Type B: cohesive soil greater than 0.5 tsf (48 kPa) but less than 1.5 tsf (144 kPa); includes angular gravel, silt, silt loam, sandy loam, and dry rock that is not stable [App. A(b), Type B(v)]. - Type C: cohesive soil 0.5 tsf (48 kPa) or less; includes gravel, sand, and loamy sand [Type C(ii)]; submerged soil or soil from which water is freely seeping; submerged rock that is not stable. - No soil is Type A if it is fissured, previously disturbed, or subject to vibration from heavy traffic, pile driving or similar effects [App. A(b)]. Soil…

Key Concepts

Hydration and ingredients - Hydration is the chemical reaction that occurs when water combines with cement; it generates heat and causes concrete to harden. Concrete does not dry out — it hardens chemically and hardens just as well under water (Carpentry and Building Construction, Ch. 8 — Hydration, p. 218). - Material is not concrete unless all four ingredients are present: cement, water, fine aggregate, coarse aggregate. Missing coarse aggregate, the result is mortar or grout (Ch. 8 — Concrete Ingredients). - A small amount of gypsum — no more than 5 percent — is added to the clinker before grinding (Ch. 8 — Portland Cement). - As more water is added, both compressive and tensile strength decrease (Ch. 8, p. 220). - Concrete gains most of its strength in the 28-day period after placement, and continues…

Key Concepts

Wall thickness (IRC Code Notes) - Rough, random, or coursed rubble stone walls: 16" (406 mm) minimum thickness — Modern Masonry 9th ed., p. 180 (Stone chapter, Code Note: Rubble Stone Wall Thickness). - Loadbearing masonry over one story: 8" minimum nominal thickness. A nominal 6" wall is permitted for a single-story home or garage if wall height does not exceed 9' and gable height does not exceed 15' — p. 248 (Code Note: Minimal Nominal Wall Thickness). - Combined units: where walls or structural members are made of different kinds or grades of units, materials, or mortars, maximum stress shall not exceed the allowable stress for the weakest unit, material, or mortar — Ch. 8, Code Note: Combined Units. - Corbel projection: maximum projection of one unit shall not exceed one-half the height of the unit…

Key Concepts

Floor framing - A wood post supporting a girder must be solid and not less than a 4×4 (often a 6×6); its ends must be flat and securely fastened — Carpentry and Building Construction, Section 15.1, p. 396. - A wood girder framed into a masonry or concrete wall pocket requires ½-inch clearance at the tops, sides, and ends to prevent moisture absorption — Ch. 15, Built-Up Girder discussion, pp. 399–401. - Sill plate anchor bolts: maximum 6 feet on center, with a bolt within 12 inches of each end of every plate — p. 402. - Holes in solid-wood floor joists must be at least 2 inches from the top and bottom edges — p. 410. - A cantilevered extension (e.g., bay window) should normally not exceed 2 feet; the joists on each side of the…

Key Concepts

Roof slope classification — Flat: below 2½ in 12; low slope: 2½ in 12 to 4 in 12; high slope: 4 in 12 or greater (Carpentry & Building Construction, Section 22.1). One square = the roofing needed to cover 100 sq. ft. of roof surface (Section 22.1).

Asphalt shingles — Standard application methods apply to 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 (Ch. 4). On 2 through 3 in 12, use the 4-inch pattern; the first shingle of each course is trimmed in a multiple of 4 inches, beginning again with a full-width shingle at the 10th course. Never use a pattern less than 4 inches (Ch. 4). A UL "wind-resistant" label requires withstanding winds up to **63…

Key Concepts

Drywall types - Drywall is a noncombustible gypsum core covered with paper — smooth face paper on the front, rough liner paper on the back. Face paper wraps the long edges but not the short ends (Carpentry and Building Construction, Ch. 32, Understanding Drywall / Standard Drywall). - Sheets are commonly 4' wide × 8' long, also available in 9', 10', 12', and 14' lengths. Most common thickness is 1/2" (Ch. 32, Standard Drywall). - Long edges are tapered so joints between panels can be filled with compound and smoothed flush. Square-cut-edge sheets are used as a substrate for paneling (Ch. 32, Standard Drywall). - Type-X fire-code drywall is 5/8" thick and contains glass fibers that prevent crumbling in extreme heat. It is required on the outer surface of walls separating an attached garage from the house,…

Alabama Home Builder Skill Exam — 5 questions (6%)

Key Concepts

Water-resistive barriers / building paper - No. 15 asphaltic felt ("15 lb. paper") is the minimum weight required by code beneath siding. No. 30 is available but heavier than the minimum. (Carpentry and Building Construction, Ch. 23 — Preventing Moisture Problems) - Building paper is applied smoothly to sheathing with staples. Succeeding (horizontal) layers lap at least 2 inches; where vertical joints are necessary, lap at least 6 inches. (Ch. 23 — Building Paper) - Housewrap must not be used beneath stucco — the stucco can bond to the housewrap so that it loses its effectiveness as a weather-resistive barrier. Building paper and wrinkle wrap (used to create a drainage plane) are acceptable behind stucco. (Ch. 23 — Housewrap / Preventing Moisture Problems) - A drainage plane is…

Key Concepts

Fuel Gas Piping — Testing & Pressure

• Test pressure: "not less than 1½ times the proposed maximum working pressure, but not less than 3 psig (20 kPa gauge), irrespective of design pressure." Where the test pressure exceeds 125 psig, it shall not exceed a value producing hoop stress greater than 50 percent of specified minimum yield strength. (IRC 2015, G2417.4.1)
• Test duration: "not less than 10 minutes." (G2417.4.2)
• Test medium: air, nitrogen, carbon dioxide or an inert gas. Oxygen shall not be used. (G2417.2)
• Leak detection: approved gas detector, noncorrosive leak detection fluid, or other approved methods. (G2417.5.1)
• Maximum design operating pressure inside buildings: "shall not exceed 5 pounds per square inch gauge (psig)" except where the piping system is welded, located in a ventilated chase or otherwise enclosed against accidental…

Key Concepts

Excavation inspections and classification - A competent person must make daily inspections for evidence of situations that could result in possible cave-ins, indications of failure of protective systems, hazardous atmospheres, or other hazardous conditions — prior to the start of work, as needed throughout the shift, and after every rainstorm or other hazard-increasing occurrence (§1926.651(k)(1)). - Type C soil: cohesive soil with unconfined compressive strength of 0.5 tsf (48 kPa) or less. Type A requires 1.5 tsf or greater; Type B is greater than 0.5 tsf but less than 1.5 tsf (Subpart P, Appendix A). - Drying test: "If the sample develops cracks as it dries, significant fissures are indicated." If a dried sample breaks easily and clumps do not pulverize easily, the material is cohesive with fissures; if they pulverize easily into very small fragments, it…