A through-fastened “classic panel” roof can keep water out for 30 years or more—but only if it sits on a flawless substrate. Crews begin by tearing off all shingles, felt, nails, and ridge vents so bare decking is in plain view. They sweep and vacuum dust, then walk every sheet with a flat bar and moisture meter. Soft plywood squares get cut back to solid joists and patched with new panels glued and ring-shank-nailed 6″ on center, preventing future screw lines from sinking into mush. Inside the attic, carpenters look for cracked rafters and loose collar ties, shoring up any sagging members so the new roof won’t telegraph dips that collect ponded water. While they’re under the deck, they check exhaust-fan ducts and soffit pathways, because a classic panel roof sheds heat quickly at night; without balanced ventilation, that rapid cooling can condense moisture on the underside of the metal. Only when the wood is dry, square, and fully vented does the project advance to waterproofing layers.

Classic panels (often 36″ coverage with full ¾″ ribs or 1¼″ corrugations) arrive pre-cut in even-inch lengths from the roll former. Before lifting any sheets, installers chalk bright reference lines 2″ in from the rake to keep panel ribs laser-straight across the slope; a crooked first sheet means a crooked roof. They fasten ribbed starter strips or “J-channel” at the eave so panel bottoms sit inside a drip path instead of flapping in the wind. Panels are then hoisted to roof jacks, stacked face-to-face with protective spacers to avoid paint scuffing, and oriented so factory cut ends align at ridges—field-cut edges always point down-slope where they’ll be tucked into trim. Staging the entire slope before screw-guns fire speeds coverage once fastening begins, reducing the time underlayment is exposed to UV or surprise afternoon showers.

Classic metal relies on exposed fasteners, and those screws either make or break long-term performance. Crews drive #10 self-tapping screws with oversized EPDM washers at every rib crest (high seam) so water drains away instead of puddling around the washer. Spacing follows engineering charts—usually 18″ on center in the field and 12″ near eaves, ridges, and gable ends where uplift pulls hardest. Guns are fitted with depth-sensing clutches: under-driven screws leave gaps, over-driven ones cut the washer. A trained installer learns to feel the sweet spot where the washer compresses into a slight “doughnut” but metal ribs stay un-dimpled. Where panels lap side-to-side, a factory-applied bead of butyl sealant squishes into a watertight strip when screws cinch down. Crews work upslope, overlapping panels at least one full rib so every seam faces away from prevailing winds that whip across the Cumberland Plateau.

Before calling the roof complete, the foreman walks every course with a calibrated nut-driver, checking that screws sit snug and washers show proper compression. He eyes each overlap for a full bead of butyl squeeze-out, wipes stray sealant, and touches up hairline scratches with factory paint pens to block rust starters. Next comes cleanup: magnetic rollers sweep lawns, patios, and driveway seams, snagging stray screws and metal shards. Off-cuts are stacked for recycling, underlayment cores hauled away, and gutters flushed of drill tailings so nothing rust-stains the new panels. Finally, homeowners receive a maintenance folder—panel profile, coil lot numbers, screw count, and the exact Sherwin-Williams or Valspar color code—plus a torque-chart showing how to re-tighten fasteners after 10–12 years if needed. With the site spotless and documentation in hand, the property owner is left with a classic exposed-fastener metal roof ready to face decades of Tennessee storms, heat waves, and winter ice without a hitch.