Arkansas Drywall - Residential Exam

Key Concepts

Installation standards. Suspended acoustical ceiling systems shall be installed in accordance with ASTM C635 and ASTM C636 (IBC 2015, Section 808.1.1.1). C635 governs the structural quality of the grid; C636 governs proper installation. Metal suspension systems for acoustical and lay-in panel ceilings shall comply with ASTM C635 and Section 13.5.6 of ASCE 7 for installation in high seismic areas (IBC 2015, Section 2506.2.1). Acoustical materials complying with Section 803 shall be installed per the manufacturer's recommendations (808.1.1). Acoustical ceiling systems that are part of fire-resistance-rated construction shall be installed in the same manner used in the assembly tested and comply with Chapter 7 (808.1.1.2).

Hanger wire. The step-by-step suspended ceiling procedure specifies hanger wire of 18 ga. for residential work and 12 ga. for commercial work, attached to lag screws or screw eyes set in the joists (Gypsum Construction Handbook 7th ed., Ch. 9 — Step-By-Step Installation).

Acoustical ratings (GCH Ch. 9 — Acoustical Ratings; Ch. 10 — Fire and Sound Tests): - NRC measures sound absorption; NRC .50 or higher offers significant sound absorption, and panels engineered for increased acoustical performance are rated .70 or above. - CAC applies to acoustical ceilings, is tested per ASTM E1414 for horizontally adjacent spaces; a CAC of 35 or higher offers significant sound attenuation, with "high-CAC" panels up to 40. - STC rates a partition's ability to attenuate sound passing through it; IIC rates a floor-ceiling assembly's effectiveness in retarding impact sound, tested per ASTM E492 and rated per ASTM E989.

Key Concepts

Gypsum panel thicknesses and framing limits - 1/2″ and 5/8″ panels are designed for framing centers up to 24″; 3/8″ panels are designed for framing centers up to 16″. 1/4″ panels are not recommended for single-layer application on open framing. (Gypsum Construction Handbook 7th ed., Page 3 — Gypsum Panel Limitations) - 5/8″ thickness is recommended for the finest single-layer construction, giving increased resistance to fire and to transmission of sound; 3/8″ is recommended for repair and remodeling over existing surfaces. (Ch. 2 Framing, Maximum Frame Spacing—Drywall Construction table, footnote (1)) - Overlaid unsupported insulation must not exceed 1.3 psf for 1/2″ panels on 24″ o.c. framing. The 2.2 psf limit applies to 1/2″ panels on 16″ o.c. framing (or sag-resistant 1/2″ on 24″ o.c.) and to 5/8″ panels on 24″ o.c. 3/8″ panels must not be overlaid with unsupported insulation at all. (Page 4 — Gypsum Panel Limitations) - Water-based texture over single-layer panels: maximum frame spacing 16″ o.c. for 1/2″ panels applied perpendicular to framing; parallel application not recommended. Exception: USG Sheetrock Brand Ultralight panels allow 24″ o.c. (Ch. 2, Spray-Textured Ceilings)

Framing - Wood supports for lath, gypsum board or gypsum panel products, and wood stripping or furring, shall be not less than 2 inches nominal thickness in the least dimension; exception, furring strips over solid backing not less than 1″ × 2″ nominal. (2015 IBC, Section 2504.1.1) - Minimum lateral load for interior partitions is 5 psf. (Ch. 10 — Structural Criteria) - Framing members more than 1/4″ out of alignment with adjacent members make it difficult to bring panels into firm contact. (Page 375 — Problem 8) - Runners to concrete/masonry: stub…

Arkansas Drywall — Residential Exam | 4 questions (13% of exam)

Key Concepts

Finishing-level definitions (GA-214-07 basis). Five industry levels were adopted jointly by AWCI, CISCA, GA, DWFC and PDCA, and ASTM recognized the specification by including levels of gypsum board finishing in ASTM C840. The number of layers of compound and the degree of finishing increase at each level. (Gypsum Construction Handbook, Finishing Drywall Systems — Finishing-Level Definitions)

• Level 0 — Unfinished. No taping, finishing or corner beads required; used in temporary construction or where final decoration has not been determined.
• Level 1 — All joints and interior angles shall have tape embedded in joint compound. Tape and fastener heads need not be covered with joint compound. Surface shall be free of excess joint compound. Tool marks and ridges are acceptable. Frequently used in plenums, attics, concealed assemblies and service corridors.
• Level 2 — Tape embedded and immediately wiped, leaving a thin coating over all joints and interior angles. Fastener heads and accessories covered with a coat of joint compound. Surface free of excess compound. Tool marks and ridges are acceptable. Specified for garages, warehouse storage and similar areas.
• Level 3 — Typically used where heavy-texture finishes or commercial-grade (heavy-duty) wall coverings will be applied. Fastener heads and accessories receive two separate coats; from Level 3 up, joint compounds must be smooth and free of tool marks and ridges. (Finishing Drywall Systems, Ch. 5 — Finishing-Level Definitions, Levels 1–3)
• Level 4 — Fastener heads and accessories shall be covered with three separate coats of joint compound. (Finishing-Level Definitions, Level 4)
• Level 5 — Highest quality. A **thin skim coat of joint…

Arkansas Drywall – Residential Exam | 3 questions (10%)

Key Concepts

Veneer plaster — coats and thickness - Veneer plaster "shall be applied in one coat not to exceed 3/16 inch (4.76 mm) thickness, provided the total thickness is in accordance with Table R702.1(1)" (IRC R702.2.1). - Interior plaster shall be not less than three coats over metal lath or wire fabric lath and not less than two coats over other permitted bases, with an exception for "gypsum veneer plaster and cement plaster specifically designed and approved for one-coat applications" (IBC 2511.1). - Veneer plaster is installed per ASTM C843; gypsum veneer base per ASTM C844 (IBC Tables 2511.1.1 and 2508.1).

Veneer plaster job environment (Gypsum Construction Handbook, Ch. 6) - Maintain building temperature "at least 55°F with a relative humidity between 20% and 50%." - "Keep air circulation at a minimum level prior to, during and following application until finish is dry." - Setting-type joint treatment (USG Sheetrock Brand Joint Tape with Durabond setting-type or Easy Sand lightweight setting-type compound) on all joints and internal angles is required where: conditions fall in the "rapid-drying" area of the graph; metal framing is specified; or wood framing at 24″ o.c. with a single-layer gypsum base veneer system (5/8″ base with one-coat veneer finish, 1/2″ or 5/8″ base with two-coat veneer finish). - Rocklath Firecode plaster base "should be used with gypsum plaster only" and "is not suitable for veneer plasters and finishes" (Ch. 7).

Key Concepts

Medical services and first aid — 29 CFR 1926.50

• First aid kit contents: Contents shall be placed in a weatherproof container with individual sealed packages for each type of item, and shall be checked by the employer before being sent out on each job and at least weekly on each job to ensure that expended items are replaced (§1926.50(d)(2)).
• First aid supplies shall be easily accessible when required (§1926.50(d)(1)).
• No accessible medical facility: In the absence of an infirmary, clinic, hospital, or physician that is reasonably accessible in terms of time and distance to the worksite, a person who has a valid certificate in first-aid training from the U.S. Bureau of Mines, the American Red Cross, or equivalent training that can be verified by documentary evidence, shall be available at the worksite to render first aid (§1926.50(c)).
• The employer shall insure the availability of medical personnel for advice and consultation on occupational health (§1926.50(a)), and provisions shall be made prior to commencement of the project for prompt medical attention in case of serious injury (§1926.50(b)).
• Proper equipment for prompt transportation of the injured person, or a communication system for contacting necessary ambulance service, shall be provided (§1926.50(e)). Where 911 emergency dispatch services are not available, telephone numbers of physicians, hospitals, or ambulances shall be conspicuously posted (§1926.50(f)(1)).
• First aid services and provisions for medical care shall be made available by the employer for every employee covered by these regulations (§1926.23).

Emergency action plans — 29 CFR 1926.35