AR General Contractor cheat sheet

The Arkansas Contractors Licensing Board (ACLB) licenses commercial contractors; a license is required to bid or contract for commercial construction projects of $20,000 or more.

License classifications set a maximum single-project dollar limit; contracting for work above the licensed classification is a violation subject to board discipline.

Contract types allocate risk: lump sum (contractor bears quantity and cost risk), unit price (owner bears quantity risk), cost-plus and GMP (owner bears most cost risk).

Federal Miller Act requires performance and payment bonds on federal construction contracts exceeding $150,000, protecting the government and unpaid subcontractors and suppliers.

Arkansas workers' compensation coverage is required for employers with three or more employees.

Change orders should be written, priced, and signed before the work is performed; unsigned field directives create disputes over scope and payment.

A licensed business entity holds its contractor license through a qualifying party who passes the required exam and meets experience requirements.

Mechanic's lien rights are purely statutory: required notices and filing deadlines must be met exactly or the lien right is lost.

Total float = Late Start − Early Start = Late Finish − Early Finish; an activity with zero total float lies on the critical path.

The critical path is the longest continuous chain of dependent activities through the network; it determines the shortest possible project duration.

Crashing shortens duration by adding resources and cost; fast-tracking shortens duration by overlapping activities and increases coordination and rework risk.

Earned value: CV = EV − AC and SV = EV − PV; positive values are favorable, negative values are unfavorable.

CPI = EV ÷ AC (under 1.0 means over budget); SPI = EV ÷ PV (under 1.0 means behind schedule).

Three-point (PERT) estimate = (Optimistic + 4 × Most Likely + Pessimistic) ÷ 6.

A designer's review of a shop drawing does not relieve the contractor of responsibility for complying with the contract documents.

Substantial completion is the point at which work is usable for its intended purpose; it typically starts warranties, ends liquidated damages, and triggers retainage release.

In finish-to-start logic, a successor activity cannot begin until its predecessor is complete.

At a scale of 1/4 inch = 1 foot, one inch on the drawing equals 4 feet; multiply a scaled measurement by 48 to convert to inches of actual size.

Board feet = (thickness in inches × width in inches × length in feet) ÷ 12.

Concrete volume in cubic yards = (length ft × width ft × depth ft) ÷ 27.

Order quantity = net quantity × (1 + waste factor); waste covers cutting, breakage, and overrun.

An 8 × 8 × 16 inch concrete masonry unit lays up at 1.125 blocks per square foot of wall face with 3/8 inch joints.

Modular brick with 3/8 inch mortar joints yields approximately 6.75 bricks per square foot of wall face.

A slope of 1/4 inch per foot equals about 2 percent grade (0.25 ÷ 12 × 100).

Plans are top-down views, sections are vertical cuts through the building, and elevations are flat exterior or interior wall views.

Labor hours = quantity × unit labor rate; duration in days = labor hours ÷ (crew size × hours worked per day).

Concrete is specified and tested for compressive strength at 28 days; 7-day breaks typically reach about 75 percent of design strength.

Lower water-cement ratio increases strength and durability but reduces workability; typical structural mixes fall near 0.40 to 0.50.

Air entrainment of roughly 4 to 7 percent provides freeze-thaw durability in exterior concrete.

Field compaction is commonly specified as a percentage (often 95 percent) of maximum dry density from a Standard Proctor test, placed in 8 to 12 inch lifts.

Structural steel wide-flange shapes are commonly ASTM A992; high-strength structural bolts are A325 or A490.

Type X gypsum board has a specially formulated core that earns a fire-resistance rating when installed in a tested assembly.

Vapor retarders are placed on the warm side of the insulation in cold climates to prevent condensation within the assembly.

Nominal lumber dimensions differ from actual: a 2 × 4 measures 1-1/2 inches by 3-1/2 inches.

Reinforcing steel must maintain specified concrete cover to protect against corrosion and provide fire resistance.

OSHA construction fall protection is required at 6 feet, on scaffolds at 10 feet, and for general industry at 4 feet.

Excavations 5 feet deep or more require a protective system (sloping, shoring, or shielding) unless a competent person determines there is no cave-in hazard.

A competent person must inspect excavations daily and after rain or other hazard-increasing events before workers enter.

Spoil piles and equipment must be kept at least 2 feet back from the excavation edge to limit surcharge loading.

Trenches 4 feet or deeper require a ladder, stair, or ramp within 25 feet of lateral travel for every worker.

Scaffolds need a stable base with a height-to-base ratio no greater than 4:1, top rails 38 to 45 inches high, and fall protection above 10 feet.

Crane and equipment operations near power lines require at least 20 feet clearance for lines up to 350 kV under 29 CFR 1926.1408.

Construction disturbing 1 acre or more requires NPDES stormwater coverage and a Stormwater Pollution Prevention Plan with best management practices.

OSHA requires reporting a work-related fatality within 8 hours and an in-patient hospitalization, amputation, or loss of an eye within 24 hours.