General Building Construction Trade Knowledge and Workmanship Standards
Structure and envelope
Arizona has no single statewide building code; local jurisdictions adopt and amend the IBC/IRC, so the authority having jurisdiction controls details. Foundations must address expansive clay soils: uniform moisture, positive drainage away from the slab, and a vapor retarder under slab-on-grade. Concrete turns on water-cement ratio, slump, curing, and joint layout - sawed control joints run roughly one-quarter of slab depth and are spaced about 24–36 times slab thickness. Reinforcement needs specified cover, and post-tension slabs must never be cut or drilled without locating tendons.
Trades
Masonry: CMU walls need grout, reinforcement, flashing, and weep holes at the cavity base. Framing: a nominal 2×4 is actually 1½" × 3½"; shear walls depend on the nailing schedule and hold-downs shown on the plans. Roofing: underlayment and flashing at valleys, penetrations, and edges fail before the field does; tile roofs need battens and adequate slope. Stucco: three coats over lath with a weep screed and control joints. Wet-area waterproofing and MEP rough-in inspections gate the following trades.
Traps
- Quoting nominal dimensions as actual dimensions.
- Assuming one city's code amendment applies statewide.
- Forgetting that roof slope drives both material selection and surface area quantities.
- Ignoring expansion and control joints, then calling the resulting cracks a defect.
Worked example: a roof rises 4 inches per 12 inches of run. For a 30-foot-wide building, half-span is 15 feet, so rise = 15 × 4/12 = 5 feet. Slope factor = √(12² + 4²) ÷ 12 = 12.65 ÷ 12 = 1.054, so 15 feet of horizontal run needs 15.8 feet of sloped surface.