Florida reroof: the plywood deck looks OK after tear-off.

Florida (FBC 8th Ed. / 2023 FBC-R) requires specific deck prep before dry-in. Do not skip these steps.

1. Re-nail the Deck (FBC-R §R905.2.1 / FBC-B §1507.2.1): 8d ring-shank nails @ 6" o.c. on all panel edges and 12" o.c. in the field (intermediate supports). This applies to all existing decks (plywood/OSB) in the High-Velocity Hurricane Zone (HVHZ: Miami-Dade/Broward) and Statewide for asphalt shingles per FBC-R §R905.2.1. Pro tip:* Use a palm nailer or gun. Missed nails = failed inspection.

1. Inspect & Replace Damaged Sheathing (FBC-R §R905.1 / §R803): Replace any panel with delamination, rot, swelling, or deflection > 1/8". Gaps between panels > 1/8" must be filled or panel replaced (FBC-R §R803.2.2). Minimum 15/32" (1/2" nom.)* thickness for 24" truss spacing (FBC-R Table R503.2.1.1(1)).

1. Tape Seams (HVHZ Only - FBC-B §1518.2 / FBC-R §R905.2.8.2): Miami-Dade & Broward ONLY: Apply 4" min. self-adhering polymer-modified bitumen tape over all plywood/OSB joints before* underlayment. This is your secondary water barrier (SWB).

1. Clean & Dry (FBC-R §R905.1): Sweep debris. Deck must be dry* (moisture < 19% per NRCA) before underlayment. No puddles, dust, or protruding nails.

1. Drip Edge (FBC-R §R905.2.8.1): Install metal drip edge* at eaves (under underlayment) and rakes (over underlayment). Overlap 2". Fasten 12" o.c.

Inspection Sequence: You must call for "Sheathing/Deck Nailing" inspection (or "Tin Tag" in some jurisdictions) before covering with underlayment. Building official verifies nail pattern, panel condition, and seam tape (HVHZ).

Licensed Pro Required? Deck replacement (structural) requires a licensed Roofing or General/Building Contractor in FL (F.S. 489.105). Simple re-nailing/prep can be done by the roofing crew.

Before drying in a Florida reroof after tear-off, even if the plywood deck looks OK, you must perform these critical steps per Florida Building Code (FBC) 2023, Section 1507 and ASCE 7-16 (wind load requirements), and manufacturer specifications:

1. Inspect for Damage: Walk the entire deck. Look for: - Soft spots, delamination, or rot (probe with screwdriver — if it sinks >1/8”, replace). - Water stains, mold, or fungal growth (indicates hidden moisture). - Loose or corroded fasteners (nails/screws pulling through or rusted). - Gaps >1/8” between sheets (must be shimmed or fastened). FBC 1507.1.1 requires the deck to be “structurally sound, clean, dry, and free of projections.”

1. Clean the Deck: Remove all debris, nails, old felt, and contaminants. Sweep or vacuum. FBC 1507.1.1: Deck must be free of dirt, oil, and loose material.

1. Check Fastening: Ensure plywood is fastened to rafters/trusses per FBC Table 2304.10.1 (minimum 6d nails @ 6” o.c. on edges, 12” o.c. in field — or equivalent screws). Re-fasten any loose sheets. Use corrosion-resistant fasteners (hot-dipped galvanized or stainless steel in coastal zones).

1. Moisture Content: Deck must be dry — moisture content ≤19% (use a pin-type meter). FBC 1507.1.1: “Deck shall be dry before application of roof covering.” If damp, allow 24–48 hrs of ventilation (open soffit/ridge vents) or use fans. Do not install underlayment over wet deck — traps moisture, causes rot and mold.

1. Repair/Replace Damaged Areas: Cut out and replace any compromised plywood with same thickness (typically 15/32” or 1/2” CDX), staggered joints, and blocked edges per FBC.

1. Apply Underlayment: Only after deck is clean, dry, and securely fastened — install approved underlayment (e.g., #30 felt or synthetic per FBC 1507.2) before shingles/tile.

If you find rot, structural deflection, or inadequate fastening — stop and consult a licensed contractor or engineer. In Florida’s high-wind, high-humidity climate, skipping deck prep risks catastrophic failure. Always follow shingle/tile manufacturer’s deck prep requirements — they may exceed code. ≤300 words.