Carpentry, Roofing, and Finishes
Carpentry, Roofing, and Finishes tests the assemblies that close the building: wood framing under FBC Chapter 23 and the NDS, roof coverings under Chapter 15, and interior and exterior finishes under Chapters 25 and 14. Florida emphasis falls on fastening, roof slope, and water management at the roof plane.
Wood framing
- Lumber must carry a grade mark; notching and boring limits are prescriptive and enforced in the field.
- Trusses are installed per the sealed truss design drawing, including temporary and permanent bracing - bracing shown on the drawing is not optional.
- Connections follow the FBC tables and the design: hurricane ties, straps, and anchor bolts form the load path.
Roofing
- Minimum slope governs the covering: asphalt shingles generally require 2:12, with double underlayment between 2:12 and 4:12; low-slope membranes are permitted down to 1/4:12; tile and metal follow the product approval and manufacturer instructions.
- Underlayment, drip edge, valley treatment, and fastening pattern must match the approved product; in the wind-borne debris region, re-roofs typically require a secondary water barrier.
- Roof coverings must be installed in the sequence that laps water shedding downward: underlayment over drip edge at the eave, and flashing integrated in the correct order.
Finishes
- Gypsum board: screw spacing, fire-rated assemblies with listed materials, and finish level agreed in the specification.
- Exterior stucco in Florida is typically a three-coat portland cement plaster over lath with a weep screed and drainage plane.
Worked example
A gable roof spans 24 feet with a 6:12 pitch and an 18-inch horizontal overhang. Run to ridge = 12 feet; rise = 12 x 6/12 = 6 feet; rafter length = the square root of (144 + 36) = 13.42 feet. Adding the overhang: run becomes 13.5 feet, rise becomes 6.75 feet, rafter length = the square root of (182.25 + 45.56) = 15.09 feet. Ordering 13.42 feet, ignoring the overhang, leaves the fascia short and the eave open.
Traps that cost marks
- Confusing slope ratios with percent (a 6:12 roof is 50 percent, not 6 percent).
- Installing shingles below 2:12 without an approved low-slope system.
- Omitting the secondary water barrier on a re-roof where required.
- Leaving truss temporary bracing in place as permanent bracing, or removing it too early.
- Specifying lightweight gypsum board in a rated assembly that requires a listed type.