Exam Cheat Sheet · Quick Reference
Arkansas Insulation - Residential Exam
Arkansas · PSI Services Contractor
Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
30
Passing score
70%
Exam time
75 min
Administered by
PSI Services Contractor
Format
Reference materials allowed
Arkansas State Portion 30 questions
General Knowledge and Theory
8 Q · 27%
Spray-On Application
3 Q · 10%
Batt / Roll Insulation
5 Q · 17%
Blown or Loose- Fill Insulation
3 Q · 10%
Rigid-Board and Reflective Insulation
2 Q · 7%
Vapor Retarders
4 Q · 13%
OSHA Safety
5 Q · 17%
Key Distinctions
Open-cell SPF (spray polyurethane foam)vsClosed-cell SPF
Open-cell semirigid water-blown polyurethane foam gives R-3.81 per inch and expands up to 120 times its liquid volume, while closed-cell SPF gives 6 to 7 per inch and expands at an average ratio of about 30:1 (or more), because open-cell cells are filled with air rather than a blowing agent.
Insulation Handbook (2001), Chapter 10 - Foamed-in-Place Insulation, Open-cell SPF sectionExtruded polystyrene (XPS)vsExpanded polystyrene (EPS)
XPS holds a consistent R-value of 5.0 per inch regardless of density and has greater compressive strength suiting it for below-grade foundation wall use, whereas EPS R-value varies with density (PIR varies with facer type; cellular glass is stable but lower).
Insulation Handbook (2001), Chapter 11 - Rigid Board InsulationCellulose loose-fillvsFiberglass and rock wool loose-fill
Cellulose absorbs 5 to 20 percent of its weight in moisture (listed as a disadvantage), while fiberglass and rock wool absorb less than 1 percent of their weight.
Insulation Handbook (2001), Chapter 7 - Loose-Fill Insulation, Cellulose sectionPerlite loose-fillvsBlown loose-fill insulation
Perlite is bagged and must be poured into place (widely poured into concrete block cavities in masonry construction) and is not suitable for blow-in installation methods.
Insulation Handbook (2001), Chapter 7 - Loose-Fill InsulationHigh-density R-30C 'superbatt'vsStandard R-30 fiberglass batt
The high-density R-30 batt with a 'C' suffix is 8¼ to 8½ inches thick so it fits nominal 2×10 framing while keeping the required 1-inch ventilation airspace, versus 9½ to 10 inches for a standard R-30 fiberglass batt.
Insulation Handbook (2001), Chapter 8 - Blanket Insulation: Batts and RollsAir leakagevsVapor diffusion
More than 90 percent of the moisture entering a perimeter structural cavity comes from air leakage, with the other 10 percent or less occurring as vapor diffusion.
Insulation Handbook (2001), Chapter 4 - Vapor and Air RetardersLow-density fiberglass battsvsHigh-density fiberglass batts
Low-density batts for 2×4 walls are usually rated R-11 (R-19 for 2×6 walls), while high-density batts for 2×4 walls are rated R-15.
Carpentry and Building Construction, Section 31.1 — Fiberglass Insulation R-ValueCellulose loose-fill R-valuevsFiberglass and rock wool loose-fill R-value
Cellulose loose-fill is approximately R-3.5 per inch, fiberglass loose-fill approximately R-2.5 per inch, and rock wool approximately R-3.2 per inch.
Carpentry and Building Construction, Section 31.1 — Loose-Fill Insulation Materials and R-ValueFirst number on a performance-rated panel stamp (e.g., 32 in '32/16')vsSecond number (e.g., 16)
The number before the slash is the maximum spacing of supports in inches for roof sheathing use; the number after the slash is the maximum spacing for subflooring use.
Carpentry and Building Construction, Section 19.5, Pages 562-563Collar ties for structural purposes onlyvsCollar ties that support a ceiling
Structural-only collar ties go at every fourth rafter pair when rafters are 16" OC and every third rafter pair at 24" OC; collar ties at every rafter pair are required only when they will support a ceiling.
Carpentry and Building Construction, Section 19.3, Page 542Wall sheathing minimum ⅜" (studs 16" OC)vsWall sheathing minimum ⅝" (siding nailed between studs)
Walls with studs 16" OC need sheathing at least ⅜" thick (½" is more common), but when finish siding requires nailing between studs, as with wood shingles, the sheathing should be at least ⅝" thick.
Carpentry and Building Construction, Section 16.1, Page 435Plywood sheet siding applied directly to studs (mild climates)vsStandard sheathing
When plywood sheet siding serves as both siding and sheathing with no separate sheathing, the plywood must be thicker and of a higher grade to maintain wall strength.
Carpentry and Building Construction, Section 16.1, Page 435Closed cornicevsCornice with rafter overhang
A closed cornice occurs where there is no rafter overhang and is seldom used on newer houses because it is difficult to provide adequate attic ventilation (no overhang for soffit vents).
Carpentry and Building Construction, Section 19.4, Page 552Wall rated STC 50 (intact)vsSame wall with a 1-square-inch hole
A hole as small as 1 square inch can reduce an STC 50 wall's performance to approximately STC 30, showing how flanking paths compromise acoustical performance.
Carpentry and Building Construction, Section 31.2 — Flanking PathsEmployers with 10 or fewer employees (emergency action plan)vsLarger employers
Per §1926.35(e)(3), employers with 10 or fewer employees may communicate the plan orally and need not maintain a written plan.
OSHA 1926 CFR 29, §1926.35(e)(3)Key Terms
Building envelope Carpentry and Building Construction, Section 31.1 — Where to Insulate
The continuous layer of insulation separating heated and/or cooled spaces from unheated spaces exposed to outdoor temperatures; everything inside is conditioned and everything outside is exposed to outdoor temperatures.
Knee wall (one-and-a-half-story house) Carpentry and Building Construction, Section 31.1 — Where to Insulate (Walls)
A half-height second-floor/attic wall that must be treated just as if it were an exterior wall for insulation, since it separates heated from unheated space.
Vapor retarder perm value Carpentry and Building Construction, Section 31.1 — Vapor Retarders
A measure of resistance to vapor transmission where a value of 0.50 perm is adequate, though it is good practice to use barriers with values less than 0.25 perm (0.75 perm is worse than the adequate threshold).
Enveloping Carpentry and Building Construction, Section 31.1 — Vapor Retarders (Enveloping)
Stapling wide rolls of plastic film over studs, plates, and window and door headers after insulating to cover the entire exposed wall; used over insulation lacking its own vapor retarder, such as unfaced batts, and considered one of the best systems for blocking vapor movement.
Vapor retarder direction in floors over unheated crawl spaces Carpentry and Building Construction, Section 31.1 — Where to Insulate (Floor Systems)
The vapor retarder in batt insulation is installed facing toward the subflooring above (the warm side) to keep moisture from the heated space out of the insulation.
Sound Transmission Class (STC) Carpentry and Building Construction, Section 31.2 — How Sound Travels
A numerical rating of a material's or assembly's ability to reduce airborne sound transmission; the higher the STC number, the better the sound barrier.
Flanking path Carpentry and Building Construction, Section 31.2 — Flanking Paths
An opening or bypass in an acoustical assembly—such as a 1-square-inch hole—that severely degrades the assembly's rated sound performance.
Radiant-heat barrier (draped installation) Carpentry and Building Construction, Section 31.1 — Radiant-Heat Barriers
A barrier draped loosely over rafters before roof sheathing is applied so it droops to leave at least 1 inch of air space to the underside of the sheathing, improving effectiveness and creating an air channel for soffit-to-ridge airflow.
Tradeoff worksheet approach (IECC) Insulation Handbook (2001), Chapter 6 - Building Codes, Standards, and Regulations
A compliance method where, as total glazing area increases, window thermal performance must improve (lower U-value) or opaque-area insulation must be increased (higher R-value) to satisfy the overall U-value requirement.
Competent person (OSHA §1926.32(f)) OSHA 1926 CFR 29, §1926.32(f), Page 31
One capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous, or dangerous, and who has authorization to take prompt corrective measures to eliminate them.
Material Safety Data Sheet (MSDS) Carpentry and Building Construction, Construction Safety & Health, Book Page 92
A manufacturer-supplied document shipped with products that explains hazards, physical data such as melting or flash point, toxicity levels, first-aid recommendations, storage and disposal, protective equipment, and spill/leak response; every worker must have access to MSDS on the job site.
First aid availability (OSHA §1926.50(c)) OSHA 1926 CFR 29, §1926.50(c)
Where no infirmary, clinic, hospital, or physician is reasonably accessible in time and distance, a person holding a valid first-aid certificate from the U.S. Bureau of Mines, the American Red Cross, or equivalent verifiable training must be available at the worksite to render first aid.
Hazardous waste containers (OSHA §1926.25(c)) OSHA 1926 CFR 29, §1926.25(c)
Containers used for garbage and other oily, flammable, or hazardous wastes such as caustics, acids, and harmful dusts shall be equipped with covers.
Personal protective equipment responsibility (OSHA §1926.28(a)) OSHA 1926 CFR 29, §1926.28, Page 31
The employer is responsible for requiring the wearing of appropriate personal protective equipment in all operations where there is exposure to hazardous conditions or where the part indicates the need for such equipment.
Common drinking cup (OSHA §1926.51(a)(4)) OSHA 1926 CFR 29, §1926.51(a)(4), Page 34
The common drinking cup is prohibited on construction job sites.
Schedules (building plans) Carpentry and Building Construction, Section 16.2, Page 440
Charts included in building plans that provide rough-opening sizes and organize window and door types and dimensions for layout and estimating.
Cripple studs Carpentry and Building Construction, Section 16.1 (Book Page 434)
Studs installed above headers and below rough sills, located where a full-length precut stud would fall if there were no opening, providing a nailing surface for sheathing outside and wall covering inside, and maintaining the same 16" or 24" on-center layout as full-length studs.
Shear wall nailing Carpentry and Building Construction, Section 16.1 (Book Page 437)
In areas where earthquakes or high winds are a common hazard, sheathing is nailed to all studs, blocking, and sills at 3 inches on center using 8d common or galvanized box nails to resist forces that separate sheathing from framing.
Fireblocking Carpentry and Building Construction, Section 16.4 Special Framing Details, Page 461
Short lengths of 2× framing lumber installed crosswise between studs to slow passage of flames through wall cavities and strengthen walls; codes may require it in walls over 10 feet high, while in standard-height walls the top and bottom plates are considered sufficient.
Skirtboard Carpentry and Building Construction, Page 723
A finish trim board running along the wall on the closed side of a stairway, covering the joint where tread and riser ends meet the wall, serving decorative and protective functions.
Class B fire extinguisher Carpentry and Building Construction, Construction Safety & Health, Page 81
Rated for fires involving grease, oil, and chemicals (Class A is wood, paper, cloth, plastic; Class C is electrical equipment; Class D is combustible metals), and combination ratings such as A:B or A:B:C also apply.
Purlin braces Carpentry and Building Construction, Section 19.3, Page 544
Members supporting a purlin system that must be spaced not more than 4' OC, be at least 2×4 stock, connect to bearing walls at no less than a 45° angle, be no longer than 8', and not connect to non-bearing walls.
Roof opening headers and trimmers Carpentry and Building Construction, Section 19.3, Page 547
Single or double headers are set at right angles to the rafters to define a chimney or skylight opening, with rafters set into the headers as joists are around a floor opening.
Formulas to Know
U-value from total R-value of an assembly
U = 1/R; example: R-20 assembly → U = 1/20 = 0.05 (lower U-value = better insulating value)Cumulative R-value of insulation thickness
Total R = (R per inch) × (inches); example: insulation at R-5 per inch × 2 inches = R-10Minimum crawl-space net ventilation area
1 sq ft of venting per 150 sq ft of crawl-space area; example: 1,200 ÷ 150 = 8 sq ft net ventilationRoof sheathing panel count with waste allowance
Panels = roof area ÷ 32 sq ft per panel, then add 5% for trim and waste; worked example: 72.19 × 0.05 = 3.6; 72.19 + 3.6 = 75.79 → 76 sheetsBoard feet for rafters, ridge board, and collar ties (board-feet table method)
(roof surface area ÷ 100) × board feet per 100 sq ft from table; for 2×6 rafters at 16" OC the table value is 102 bf per 100 sq ft — example: 2,100 ÷ 100 = 21; 21 × 102 = 2,142 board feet (includes common rafters, hip and valley rafters, ridge boards, and collar ties)Squaring wall layout (3-4-5 rule)
Measure 3 ft along one chalk line and 4 ft along the other; the diagonal must be exactly 5 ft for a 90° corner — if it reads otherwise (e.g., 5 ft 1 in.), adjust one layout line until the diagonal is exactly 5 ft before locating remaining wallsRidge board size relative to rafters
Use nominal 2" lumber slightly wider than the rafter stock so angled rafter end cuts bear fully; example: 2×8 rafters → 2×10 ridge boardMinimum toilet facilities (OSHA Table D-1)
20 or fewer employees → minimum 1 toilet facilityAnchor bolt placement at bottom plate ends (slab foundation)
An anchor bolt must fall within 12 inches (maximum) of the end of each section of bottom plateFirst aid kit inspection frequency (OSHA §1926.50(d)(2))
Check contents before being sent out on each job and at least weekly on each job to replace expended items