AL General Contractor cheat sheet

Retainage is commonly 5–10% withheld from each progress payment and released per contract terms at substantial completion or final acceptance.

Critical path method (CPM): the critical path is the longest continuous path through the schedule network and has total float equal to zero.

A change order is a written modification to contract scope, price, or time; it should be signed by owner and contractor before changed work proceeds.

Bid bonds are typically 5–10% of the bid amount; performance and payment bonds are typically 100% of the contract amount.

Lien deadlines are set by state statute and run from last furnishing of labor or materials or from recording a notice; a missed deadline extinguishes the lien right.

The schedule of values allocates the contract sum by work item, and progress payments are calculated as percent complete against those line items.

Cost variance = budgeted cost − actual cost; a negative variance indicates a cost overrun.

Workers' compensation insurance covers employee on-the-job injury; commercial general liability excludes employee bodily injury.

Liquidated damages are a fixed per-day amount stated in the contract; actual damages are proven losses and are not fixed in advance.

OSHA requires a protective system for trenches 5 ft (1.5 m) or deeper; a ladder, ramp, or stairs is required for egress at 4 ft depth.

Maximum allowable excavation slopes: Type A soil 0.75H:1V, Type B soil 1H:1V, Type C soil 1.5H:1V.

Spoil piles and heavy equipment must be kept at least 2 ft back from the trench edge.

Exterior footings must bear below the local frost depth to prevent frost heave.

Backfill is commonly compacted to 95% of maximum dry density as determined by ASTM D698 Standard Proctor.

Allowable soil bearing capacity is reported in psf by the geotechnical engineer and governs footing size.

Dewatering must lower groundwater below the excavation bottom before excavation and maintain it during work.

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

Benching, sloping, shoring, and shielding are the four OSHA protective system options for excavations.

Concrete design strength f'c is the 28-day compressive strength used as the basis for structural design and acceptance.

A lower water-cement ratio increases compressive strength and reduces permeability; typical structural ranges are about 0.40–0.50.

The slump test (ASTM C143) measures concrete consistency and workability and is performed at the point of discharge.

Moist curing maintains moisture and temperature; 7 days is typical and longer periods are used for high-early-strength or severe exposure.

Formwork for soffits is removed only after concrete reaches the strength assumed in the shoring design; side forms may be removed earlier.

Specified rebar cover varies with exposure: 3 in for concrete cast against earth and 2 in for surfaces exposed to weather, unless the code requires otherwise.

Mortar types in descending strength are M, S, N, O, and K; Type N is common for above-grade moderate-load masonry.

CMU cores are filled with grout, consolidated with a vibrator, and verified by masonry prism tests when required.

Cold-weather concrete must be protected from freezing until it reaches about 500 psi.

ASTM A992 is the common wide-flange structural steel grade with a minimum yield strength Fy = 50 ksi.

A325 and A490 are high-strength structural bolts used in pretensioned or slip-critical connections.

Shear studs welded through metal deck transfer horizontal shear between steel beams and the concrete slab, producing composite action.

Structural welding is governed by AWS D1.1; inspection includes visual examination and nondestructive testing such as ultrasonic or radiographic.

Steel joists and metal deck require temporary bracing until permanent bracing and deck attachment are complete.

Rough carpentry lumber must be grade-stamped and have moisture content suitable for its use, commonly kiln-dried (KD) framing.

Sprayed fireproofing on structural steel provides the fire-resistance rating specified for the building assembly.

Erection tolerances and responsibilities for structural steel follow the AISC Code of Standard Practice.

Joist hangers and metal connectors must be installed in accordance with the manufacturer's published instructions and approved submittals.

A vapor retarder is placed on the warm side of insulation to limit vapor diffusion and prevent condensation within the assembly.

Low-slope roofs have a slope less than 3:12; steep-slope roofs exceed 3:12.

Base flashing and counterflashing overlap at roof-to-wall junctions to shed water; counterflashing is anchored into a reglet or wall.

Below-grade waterproofing membrane is applied to the positive (water) side of the wall.

Insulation thermal resistance is stated as R-value; higher R-value means greater resistance to heat flow.

A typical low-slope roof assembly from bottom up is deck, vapor barrier, insulation, cover board, membrane, and flashing.

Positive drainage requires slope to drains or scuppers, commonly 1/4 in per ft on low-slope roofs.

A weather-resistant barrier is installed behind cladding and lapped shingle fashion so upper layers shed over lower layers.

A fire door rating is determined by the fire-resistance rating of the wall opening it protects, such as 20, 45, 60, or 90 minutes.

Egress doors require a minimum clear width of 32 in, with 36 in typical for the door leaf.

Tempered safety glazing is required in hazardous locations including doors, sidelights, and glazing close to the floor.

Gypsum board finish levels range from 1 to 5; Level 5 adds a skim coat for glossy paint or critical lighting.

NFRC ratings for windows include U-factor (heat loss) and SHGC (solar heat gain).

Panic hardware is required on egress doors serving high occupant loads and must release with a single motion.

Interior egress doors may not exceed 5 lb opening force under ADA, excluding fire-rated doors.

Storefront systems are non-load-bearing exterior framing, while curtain walls are designed to accommodate building movement and are often unitized.

Clash detection in a BIM model identifies conflicts among structural, mechanical, electrical, and plumbing systems before fabrication.

Sleeves and openings must be coordinated with structural drawings; cutting reinforcing steel requires structural engineer approval.

Sanitary drain pipe slope is commonly 1/4 in per ft for pipe 2 in and smaller, with lesser slopes permitted for larger pipe.

Duct hanger spacing and support methods follow SMACNA standards and the project specifications.

Plumbing systems are pressure-tested before concealment to verify joints are leak-free at the specified test pressure.

Fire sprinkler head spacing, coverage, and clearance below deflectors must comply with NFPA 13 and the approved shop drawings.

Conduit fill, box sizing, and conductor ampacity are governed by NFPA 70 (National Electrical Code).

Commissioning verifies that installed systems perform in accordance with the design intent and owner's project requirements.

OSHA requires fall protection for construction workers exposed to falls of 6 ft or more, and 10 ft on scaffolds.

Guardrail top rails must be 42 in above the walking surface, plus or minus 3 in, with a midrail.

The IBC occupancy classification is based on building use and determines egress, fire separation, and construction type requirements.

Plan scale expresses drawing dimension to actual dimension, such as 1/4 in = 1 ft, and is used to measure distances.

Section markers on plans identify the drawing sheet and detail where a cut section is shown.

Elevation callouts show the height of a feature relative to a stated datum, commonly mean sea level or project zero.

GFCI protection is required for temporary receptacles on construction sites per OSHA and the NEC.

Fire extinguishers must be spaced according to hazard class and rated travel distance, and be mounted and accessible.

Door and window schedules list type marks, sizes, hardware sets, fire ratings, and glazing requirements for each opening.