WV General Contractor cheat sheet

Critical path is the longest duration path through a network; any delay on it delays project completion by the same amount.

Total float = late start minus early start (equivalently late finish minus early finish); zero float indicates a critical-path activity.

Retainage in West Virginia public improvement contracts is commonly 5% of each progress payment until substantial completion.

Liquidated damages must be a reasonable forecast of anticipated harm at contract formation to be enforceable rather than a penalty.

A change order requires written authorization; work performed without one may be treated as uncompensated extra work.

Mechanic's lien rights in West Virginia generally require a notice of lien to the owner within 100 days of last furnishing labor or materials.

Schedule performance index (SPI) = earned value divided by planned value; SPI below 1.0 means work is behind schedule.

Cost performance index (CPI) = earned value divided by actual cost; CPI below 1.0 means cost overrun.

Substantial completion starts warranty periods and typically reduces retainage; final completion releases remaining retainage.

Unit price = total cost divided by quantity; extended cost = unit price times quantity.

Overhead and profit are applied as percentages to the direct cost subtotal; order of markup application changes the final bid.

Contingency is an allowance for known unknowns and is separate from overhead and profit in the estimate.

Quantity takeoff for concrete: volume = length x width x thickness; add 5-10% waste for formed and flatwork placements.

Masonry unit count = wall area divided by unit face area including mortar joint; add waste factor for cuts and breakage.

Labor cost = productivity rate (labor hours per unit) times quantity times fully burdened hourly wage.

Bid bond typically covers 5-10% of the bid amount; performance and payment bonds typically cover 100% of the contract price.

Balanced bidding avoids front-loading; unbalanced bids that rely on quantity errors may be rejected as nonresponsive.

Escalation for material price volatility is handled by a stated allowance or a price-adjustment clause, not by inflating unit prices.

Concrete compressive strength is specified at 28 days; typical structural mixes range from 2,500 to 5,000 psi.

Water-cement ratio controls concrete strength and durability; lower ratio yields higher strength and lower permeability.

Standard concrete cure requires maintained moisture and temperature; cold weather below 40 F requires protection per ACI 306.

Nominal 2x4 lumber is actually 1-1/2 in by 3-1/2 in; nominal 2x10 is 1-1/2 in by 9-1/4 in.

Rebar lap splice length depends on bar size, concrete strength, and development length; typical laps are 30-40 bar diameters.

Type X gypsum board provides a one-hour fire rating in rated assemblies; Type C offers improved core for specific rated designs.

Footing size is governed by soil bearing capacity: area required = total load divided by allowable soil bearing pressure.

Moisture barrier placement: vapor retarder goes on the warm side of insulation in cold climates; housewrap goes outside sheathing under siding.

Asphalt shingle underlayment is required; ice dam protection membrane is required at eaves in cold climates per code.

OSHA fall protection is required for general industry at 4 ft and for construction at 6 ft above a lower level.

Excavations 5 ft or deeper require a protective system unless the excavation is entirely in stable rock.

Excavations 4 ft or deeper require a means of egress (ladder, ramp, or stairway) within 25 ft of lateral travel.

Competent person must inspect excavations daily and after rain or other hazard-increasing events before employees enter.

Scaffolds require guardrails at 10 ft and full planking; scaffold platforms must be fully planked and not more than 14 in from the work face.

West Virginia contractor licensing: a general contractor license is required for projects of $2,500 or more in labor and materials combined.

West Virginia requires workers' compensation coverage for employees; a valid certificate must be maintained for licensure.

Hazard communication requires safety data sheets (SDS) for each hazardous chemical on site and employee training.

Silica exposure: Table 1 of OSHA 1926.1153 specifies engineering controls and respiratory protection for common construction tasks.