OK General Contractor flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Critical path

The longest sequence of dependent activities through a project network; its length sets the minimum project duration, and any delay on it delays the project unless float is recovered.

Earned value CPI

Cost Performance Index equals earned value divided by actual cost. A value below 1.0 indicates the project is spending more than the work performed is worth.

Retainage

A percentage withheld from each progress payment until final completion. Oklahoma public contracts commonly cap it at 5 percent; private contracts often use 5 to 10 percent.

Scale conversion

On a drawing scaled one-quarter inch equals one foot, one inch on paper represents four feet in reality. Multiply measured paper length by the scale denominator.

Board foot

A lumber volume unit equal to a board one inch thick, twelve inches wide, and twelve inches long. Formula: thickness times width times length divided by twelve.

Rebar weight No. 5

A number 5 deformed bar weighs about 1.043 pounds per linear foot. Bar weight per foot approximates the bar number squared divided by 2.67.

Soil swell

The percentage volume increase when bank soil is excavated and loosened. Bank volume multiplied by one plus swell gives loose volume for hauling calculations.

Proctor compaction

A laboratory test establishing maximum dry density and optimum moisture content for a soil. Field compaction is specified as a percentage of that maximum dry density.

Trench protective systems

OSHA requires a protective system for excavations five feet or deeper unless in stable rock. Sloping, shoring, shielding, or benching are acceptable methods.

Water-cement ratio

The ratio of water to cementitious material by weight. Lower ratios increase strength and reduce permeability; typical structural concrete uses 0.40 to 0.50.

Concrete curing

Maintaining moisture and temperature so cement hydrates. Moist curing for about seven days is typical; cold weather requires protection near or below 40 degrees Fahrenheit.

Masonry mortar types

Type M is highest strength, Type S is moderate-high, Type N is general purpose above grade, and Type O is low strength for interior non-load-bearing use.

High-strength bolts

A325 and A490 bolts used in structural steel connections. Slip-critical joints require specified tension achieved by turn-of-nut or calibrated wrench methods.

Nominal versus dressed lumber

Nominal size is the name, such as 2x4. Dressed actual size is smaller, about 1-1/2 by 3-1/2 inches, and actual dimensions govern design calculations.

Joist hanger fasteners

Connectors must use the manufacturer's specified fasteners. Substituting different nails or screws voids the published load capacity and may fail inspection.

R-value and U-factor

R-value measures thermal resistance; U-factor is its reciprocal. Lower U-factor means better insulating performance for windows and assemblies.

Flashing sequence

At openings, install the sill pan first, then jamb flashing, then head flashing. Upper layers must lap over lower layers so water sheds outward.

SHGC

Solar Heat Gain Coefficient measures the fraction of solar radiation admitted through a window. Lower values reduce cooling loads in hot climates such as Oklahoma.

Sanitary drain slope

Drain lines typically slope one-quarter inch per foot for two-inch and smaller pipe and one-eighth inch per foot for three-inch and larger pipe.

Electrical working clearance

Clear space in front of electrical equipment, generally 36 inches and greater for higher voltages. The space must remain clear and cannot be used for storage.

Firestop penetration

A listed system restoring the fire rating of a wall or floor where pipe, conduit, or duct passes through. Fire dampers are required where ducts penetrate rated assemblies.

Fall protection threshold

OSHA requires fall protection at six feet or more in construction. Guardrails, safety nets, or personal fall arrest systems are acceptable controls.

Fall arrest forces

Personal fall arrest must limit arresting force to 1,800 pounds and free fall to six feet or less. Anchors must support 5,000 pounds per worker.

Hazard Communication

Requires labeled containers, accessible safety data sheets, a written program, and employee training for workers exposed to hazardous chemicals on site.

Oklahoma CIB

The Construction Industries Board licenses trade contractors and administers construction codes. Local jurisdictions may adopt and enforce their own amendments.

Oklahoma lien filing

A lien statement is filed with the county clerk within the statutory period, generally 90 days after last furnishing labor or materials for most claimants.

Conditional lien waiver

A waiver that becomes effective only when payment is received. An unconditional waiver is effective upon signing, so never sign one before funds clear.

Public works lien remedy

Mechanics' liens do not attach to public property. Claimants instead pursue payment bonds, following the statutory notice and claim procedures for public contracts.

Roof slope factor

A multiplier converting plan area to sloped area. A 4:12 pitch has a factor near 1.054; steeper pitches increase the factor and material quantities.

Expansive clay soils

Fine-grained soils with high plasticity index that swell when wet and shrink when dry. Common in Oklahoma; mitigated by over-excavation, moisture control, or deep foundations.

Air barrier continuity

A sealed, continuous layer controlling infiltration. Air leakage transports far more moisture and heat than vapor diffusion, so continuity at joints matters most.

Lockout tagout

A procedure controlling hazardous energy during servicing. Only authorized employees apply locks and tags, and energy must be verified as isolated before work begins.