Arkansas Residential Builder Exam

General Carpentry

Key Concepts

Span tables - A span table is "a list of distances that a particular structural product can span between structural supports, such as walls or columns." Each I-joist manufacturer provides its own span tables and installation details — use the table for the specific product. (Carpentry and Building Construction, Sec. 13.2, p. 355) - Steps to read a floor-joist span table: (1) determine the live load category (e.g., 40 psf); (2) locate the species or group column; (3) refer to the grade column; (4) follow the row right to the required span; (5) follow that column upward to the on-center spacing; (6) read the lumber dimensions in the row above. (Sec. 14.1, p. 383) - "DFL" on plans and in span tables means Douglas fir-larch. (IRC, Table R502.3.1(2))

Layout - First floor joist: mark 15¼" from the outside edge of the sill plate to the edge of the first joist, then mark every 16". "Double-check to be sure that a joist is centered every 4'," so sheathing panel edges always fall on a joist centerline. (Sec. 15.2, p. 405) - Lapped joists over a girder: offset the opposite plate layout by 1½" so joists…

Key Concepts

Concrete materials and cement types - Concrete is made by mixing cement, coarse aggregate, fine aggregate, and water; the chemical reaction that hardens it is hydration (Carpentry and Building Construction, Section 8.1, p. 218). - Type IV (Low-Heat) Portland cement is used when the heat generated by hydration must be kept low and slower developing strength is not objectionable — designed for massive structures such as dams (Modern Masonry 9th ed., Ch. 18, p. 383). - Ready-mix is ordered by bags of cement per cubic yard. Five-bag mix is the minimum amount required for most work; six-bag mix is commonly specified where high strength is needed or where steel reinforcement is used (Carpentry, Section 8.2, p. 226). - The IRC specifies concrete exposed to a freezing and thawing environment be air entrained with a minimum total air content of 5% (Modern Masonry, Ch. 18, Section 18.1.4, IRC Code Note).

Estimating and Plan Reading

Key Concepts

Types of cost estimates. Three types of estimates are the pre-design estimate, the quantity takeoff, and the unit-cost estimate (Carpentry and Building Construction, Section 2.4, Pages 61–62 and Chapter 2 objectives).

• Pre-design estimate — made before the exact features of the house are known. The builder multiplies the square footage of the house by the approximate construction costs per square foot in that community. Also called a preliminary, ballpark, or conceptual estimate. Architects may use it to figure a design fee; insurance companies use it to establish approximate replacement costs.
• Quantity takeoff — a cost estimate in which every piece of material required to build the house is counted and priced. Also called a complete construction cost estimate or quantity survey. A complete set of building plans is necessary to prepare one, and the estimator must also review the project specifications carefully. It is time consuming but can later be used for ordering materials.
• Unit-cost estimate — the house is divided into components; this is faster than the quantity takeoff method. **The unit for walls is typically lineal feet (LF); the unit for floors and roofs is square…

Key Concepts

Brick materials and manufacture - Green bricks are bricks that have not been fired. Brick contains from 5% to 30% moisture as it comes from the molding or extruding machines; most of this moisture must be evaporated before firing (Modern Masonry, p. 115). - Grade SW building brick is highly resistant to frost action and is used where bricks are exposed to freezing weather — e.g., foundation courses or retaining walls. Grade MW is for exposure to below-freezing temperatures where the brick is not likely to be permeated with water (e.g., face of a wall aboveground). Grade NW is designed for backup on interior masonry (Modern Masonry, p. 116). FBX/FBS/FBA are facing brick types, not building brick grades. - Solid masonry unit: "one whose cross-sectional area in every plane parallel to the bearing surface is 75% or more of its gross cross-sectional area measured in the same plane." Cored bricks still count as solid if holes are less than 25% of the area. A hollow masonry unit has less than 75% solid material (Modern Masonry, p. 123).

Key Concepts

Rafter and ridge members - A ridge board is usually nominal 2" lumber slightly wider than the rafter stock so angled rafter cuts bear fully on it — 2×8 rafters use a 2×10 ridge board (Carpentry and Building Construction, Sec. 19.1, p. 530). IRC: ridge board not less than 1-inch nominal thickness and not less in depth than the cut end of the rafter; rafters framed not more than 1½ inches offset from each other or directly opposite with a gusset plate (IRC 2015 R802.3). - At valleys and hips there shall be a valley or hip rafter not less than 2-inch nominal thickness and not less in depth than the cut end of the rafter; hip and valley rafters shall be supported at the ridge by a brace to a bearing partition or designed to carry the load (R802.3). - Hip and valley rafters are the same thickness as common rafters but should be 2 inches wider in nominal dimension (2×6 commons → 2×8 hips) to give full bearing for intersecting jack rafters (Ch. 18, p. 504). - Shortening allowance: hip framed against the ridge board with a single side cut = one-half the 45° thickness…

Key Concepts

Site layout and reference lines - The plot plan shows the building's location on the lot; marking it on the land is site layout (Carpentry and Building Construction, Ch. 9 — Basic Site Layout). - A building planned parallel to an existing street or marked property line can use that line as a reference line, making it possible to stake out the site without a surveying instrument (Carpentry, Ch. 9 — Measuring From a Reference Line). - Theodolite: a transit that reads horizontal and vertical angles electronically, needs no vernier scale, and displays measurements on an LCD screen; used when extremely accurate measurements are required (Carpentry, Ch. 9 — Types of Instruments). A level's telescope is fixed in a horizontal plane and turns only side to side. A laser level has no telescope and projects a beam along a horizontal plane; its drawback is that the light can be hard to see in bright daylight. - Leveling a transit head: center the bubble over the first set of opposing leveling screws, rotate the telescope 90° so it is over the second set, repeat, then recheck both positions until the bubble is within one graduation on either side…

OSHA Safety

Key Concepts

Employee emergency action plans (§1926.35). The plan "shall be in writing (except as provided in the last sentence of paragraph (e)(3))" (§1926.35(a)). Under §1926.35(e)(3), "For those employers with 10 or fewer employees the plan may be communicated orally to employees and the employer need not maintain a written plan." Required elements include emergency escape procedures and route assignments, procedures for employees operating critical plant operations, procedures to account for all employees after evacuation, rescue and medical duties, preferred means of reporting fires and other emergencies, and names or job titles of contacts (§1926.35(b)). The employer must establish an employee alarm system complying with §1926.159 (§1926.35(c)(1)).

Safety training and education (§1926.21(b)). The employer "shall instruct each employee in the recognition and avoidance of unsafe conditions" (b)(2). Employees "required to handle or use poisons, caustics, and other harmful substances shall be instructed regarding the safe handling and use, and be made aware of the potential hazards, personal hygiene, and personal protective measures required" (b)(3). Employees handling flammable liquids, gases, or toxic materials must be instructed in safe handling and made aware of requirements in subparts D, F, and other applicable subparts (b)(5).