Exam Cheat Sheet · Quick Reference

Arkansas Insulation - Commercial 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

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 SPFvsClosed-cell SPF

Open-cell semirigid water-blown polyurethane foam is R-3.81 per inch and expands up to 120 times its liquid volume, while closed-cell SPF is R-6 to R-7 per inch and expands at an average ratio of about 30:1 (or more), because open-cell cells hold air rather than a blowing agent.

Insulation Handbook (2001), Chapter 10 - Foamed-in-Place Insulation, Open-cell SPF section

Extruded polystyrene (XPS)vsExpanded polystyrene (EPS)

XPS holds a consistent R-value of 5.0 per inch regardless of density and has greater compressive strength suited for below-grade foundation walls, while EPS R-value varies with density (PIR varies with facer type; cellular glass is stable but lower).

Insulation Handbook (2001), Chapter 11 - Rigid Board Insulation

Cellulose loose-fillvsFiberglass / rock wool loose-fill

Cellulose absorbs 5 to 20 percent of its weight in moisture (a listed disadvantage), whereas fiberglass and rock wool absorb less than 1 percent of their weight.

Insulation Handbook (2001), Chapter 7 - Loose-Fill Insulation, Cellulose section

Air leakagevsVapor diffusion

More than 90 percent of moisture entering a perimeter structural cavity comes from air leakage, with the other 10 percent or less from vapor diffusion.

Insulation Handbook (2001), Chapter 4 - Vapor and Air Retarders

Perlite loose-fillvsBlown loose-fill materials

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 Insulation

High-density R-30C superbattvsStandard R-30 fiberglass batt

The 'C' suffix cathedral-ceiling superbatt 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 batt.

Insulation Handbook (2001), Chapter 8 - Blanket Insulation: Batts and Rolls

Low-density fiberglass battsvsHigh-density fiberglass batts

For 2×4 walls low-density batts are usually rated R-11 and high-density batts R-15; low-density batts for 2×6 walls are rated R-19.

Carpentry and Building Construction, Section 31.1 — Fiberglass Insulation R-Value

Cellulose vs fiberglass vs rock wool loose-fill R-valuevs—

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-Value

Collar ties that support a ceilingvsCollar ties used only structurally

Collar ties at every rafter pair are required only when they support a ceiling; when used only structurally they attach to every fourth rafter pair at 16" OC spacing and every third rafter pair at 24" OC spacing.

Carpentry and Building Construction, Section 19.3, Page 542

First number on a '32/16' panel stampvsSecond number on the stamp

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 562-563

Wall sheathing at 16" OC studsvsSheathing where finish siding is nailed between studs

Walls with studs 16" OC need sheathing at least ⅜" thick (½" is more common), but where 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 435

Written emergency action planvsOral emergency action plan

Under §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)

Class B fire extinguishervsClass A / C / D extinguishers

Class B covers grease, oil and chemical fires; Class A covers wood, paper, cloth and plastic; Class C covers electrical equipment; Class D covers combustible metals (combination ratings such as A:B or A:B:C also serve Class B fires).

Carpentry and Building Construction, Construction Safety & Health, Page 81

Closed cornice (no rafter overhang)vsCornice with rafter overhang

A closed cornice is seldom used on newer houses because the absence of overhang eliminates the usual soffit-vent location, making adequate attic ventilation difficult.

Carpentry and Building Construction, Section 19.4, Page 552

Key Terms

Competent person (OSHA) OSHA 1926 CFR 29, §1926.32(f), Page 31

Per §1926.32(f), one capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them.

First aid kit inspection OSHA 1926 CFR 29, §1926.50(d)(2)

Per §1926.50(d)(2), kit contents shall be checked by the employer before being sent out on each job and at least weekly on each job so expended items are replaced.

First-aid coverage at remote sites OSHA 1926 CFR 29, §1926.50(c)

Per §1926.50(c), where no infirmary, clinic, hospital or physician is reasonably accessible in time and distance, a person with 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.

Personal protective equipment responsibility OSHA 1926 CFR 29, §1926.28, Page 31

Per §1926.28(a), the employer is responsible for requiring the wearing of appropriate PPE in all operations where there is exposure to hazardous conditions or where the part indicates its need to reduce hazards.

Hazardous waste containers OSHA 1926 CFR 29, §1926.25(c)

Per §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.

Common drinking cup OSHA 1926 CFR 29, §1926.51(a)(4), Page 34

Per §1926.51(a)(4), the common drinking cup is prohibited on construction job sites.

Material Safety Data Sheet (MSDS) Carpentry and Building Construction, Construction Safety & Health, Book Page 92

A manufacturer-supplied document shipped with products that lists 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.

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.

Knee walls Carpentry and Building Construction, Section 31.1 — Where to Insulate (Walls)

Half-height attic walls on the second floor of a one-and-a-half-story house that are treated just as if they were exterior walls for insulation because they separate heated from unheated space.

Sound Transmission Class (STC) Carpentry and Building Construction, Section 31.2 — How Sound Travels

A numerical rating of the ability of a material or combination of materials 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

A bypass opening that defeats acoustical performance—a hole as small as 1 square inch in a wall rated STC 50 can reduce that wall's performance to STC 30.

Enveloping Carpentry and Building Construction, Section 31.1 — Vapor Retarders (Enveloping)

The vapor-retarder technique of stapling wide rolls of plastic film over studs, plates and window and door headers to cover the entire exposed wall after insulating; used over insulation lacking its own retarder (such as unfaced batts) and considered one of the best systems for blocking vapor movement.

Vapor retarder perm value Carpentry and Building Construction, Section 31.1 — Vapor Retarders

A value of 0.50 perm is adequate, but it is good practice to use barriers with values less than 0.25 perm; lower perm means higher resistance to vapor transmission.

Floor-system vapor retarder orientation Carpentry and Building Construction, Section 31.1 — Where to Insulate (Floor Systems)

In batt insulation over an unheated crawl space, the vapor retarder faces toward the subflooring above (the warm side) to keep moisture from the heated space out of the insulation.

Radiant-heat barrier air space Carpentry and Building Construction, Section 31.1 — Radiant-Heat Barriers

When draped loosely over rafters before roof sheathing is applied, the barrier should droop to leave at least 1 inch of air space between the barrier and the underside of the sheathing, creating an air channel for soffit and ridge vent airflow.

IECC tradeoff worksheet approach Insulation Handbook (2001), Chapter 6 - Building Codes, Standards, and Regulations

A compliance method in which increasing total glazing area requires improving window thermal performance (lowering U-value) or increasing insulation in the opaque portion (raising R-value) to satisfy the overall U-value requirement.

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 where a full-length precut stud would fall, 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 earthquake or high-wind areas, sheathing is nailed to all studs, blocking and sills 3 inches on center with 8d common or galvanized box nails to resist forces separating 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 the passage of flames through wall cavities and strengthen walls; codes may require it in walls over 10 feet high, since in standard-height walls the top and bottom plates suffice.

Ridge board Carpentry and Building Construction, Section 19.1, Page 530

Nominal 2" lumber slightly wider than the rafter stock (for example, a 2×10 ridge with 2×8 rafters) so the angled rafter end cuts bear fully on it.

Skirtboard Carpentry and Building Construction, Page 723

A finish trim piece running along the wall on the closed side of a stairway, covering the joint where tread and riser ends meet the wall for decoration and protection.

Purlin braces Carpentry and Building Construction, Section 19.3, Page 544

Braces supporting a purlin system, spaced not more than 4' OC, at least 2×4 stock, connected to bearing walls at no less than a 45° angle, no longer than 8', and never connected to non-bearing walls.

Formulas to Know

U-value from R-value of an assemblyU = 1/R; example: R-20 assembly → U = 1/20 = 0.05 (lower U-value = better insulating value)

Cumulative R-value of insulation thicknessTotal R = (R-value per inch) × (inches); example: 2 in. of R-5 per inch = R-10

Crawl-space ventilation net area

1 sq ft of net venting per 150 sq ft of crawl-space area; example: 1,200 ÷ 150 = 8 sq ft (crawl space had a vapor retarder over the soil)

Roof sheathing panel count

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 sheets

Rafter lumber by board-feet table (rafters, ridge board, collar ties, hip and valley rafters)

(roof surface area ÷ 100) × table board-feet per 100 sq ft; worked example: 2×6 rafters at 16" OC = 102 bf/100 sq ft, 2,100 ÷ 100 = 21, 21 × 102 = 2,142 board feet

Squaring wall layout (3-4-5 rule)

Measure 3 ft along one leg and 4 ft along the other; the diagonal must be exactly 5 ft for a 90° corner — a reading such as 5 ft 1 in. means adjust one layout line until it measures 5 ft before marking remaining walls

Minimum toilet facilities on a jobsitePer §1926.51(c)(1) Table D-1: 20 or fewer employees → minimum of 1 facility

Anchor 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 plate

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