How to Install 3-Foot Metal Roofing Panels
Learn to square, align, seal, and screw down 36-inch exposed fastener metal roofing panels with proper overlap and torque for a leak-proof finish.
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🧰 Required Tools & Equipment
- ✓ Cordless drill with depth-sensing clutch
- ✓ 1/4-inch or 5/16-inch magnetic hex driver bit
- ✓ Aviation tin snips
- ✓ Chalk line
- ✓ Tape measure
- ✓ Fall arrest harness and roof anchor
📦 Materials & Supplies
- ✓ 36-inch coverage ribbed metal roof panels
- ✓ Self-drilling metal roof screws with EPDM washers
- ✓ Butyl lap sealant tape (3/8-inch or 1/2-inch)
- ✓ Inside and outside profiled foam closure strips
- ✓ Eave drip edge and rake trim flashing
⚠️ Safety Checkpoints & Warnings
- • Inspect and secure safety harness and lanyard to a certified roof ridge anchor before starting.
- • Wear ANSI cut-resistant level 4+ gloves when lifting, carrying, or cutting sheet metal panels.
- • Do not walk or work on metal panels during rain, morning dew, frost, or high wind conditions.
📋 Step-by-Step Guide (6 Steps)
Install Eave Drip Edge and Inside Closures
Fasten metal eave drip edge flashing along the fascia with roofing nails spaced every 12 inches. Apply a continuous strip of butyl sealant tape on top of the drip edge flange. Press inside foam closure strips firmly into the butyl tape along the entire eave line so the contours match the panel ribs.
- • Metal drip edge lies flat and straight along the entire eave line.
- • Foam closure strip is stuck parallel to the roof edge on top of tacky butyl tape.
- • Installing the closure strips backward or mismatched to the panel rib profile.
- • Omitting butyl tape underneath the foam closure, allowing water to wick under.
Snap a Square Reference Line
Measure across the roof eave from the gable rake edge the width of your first panel (typically 36 inches) and mark the spot. Measure the same distance at the roof ridge and mark it. Snap a chalk line between the two marks to create a true 90-degree guide relative to the eave.
- • A crisp, straight chalk line runs vertically from the ridge to the eave.
- • Line is perpendicular to the eave edge verified with a 3-4-5 triangle check.
- • Assuming the roof rake edge is perfectly square and aligning the first panel strictly to the edge.
Place and Align the First Panel
Carry the first metal panel onto the roof, keeping the overlap edge facing away from the prevailing wind. Align the side of the panel directly along the chalk line with a 1.5-inch overhang past the eave drip edge. Temporarily drive one screw at the top center purlin to hold the panel in position.
- • Panel side edge aligns parallel with the snapped chalk line.
- • Bottom panel edge overhangs the eave uniformly by 1.5 inches.
- • Letting the panel slide downward past the desired overhang while reaching for screws.
- • Placing the underlap edge toward the gable instead of the overlap edge.
Drive Fasteners into the First Panel
Drive self-drilling screws into the flat pans immediately next to the major ribs over each support purlin. Hold the drill perpendicular (90 degrees) to the metal surface. Drive screws until the EPDM rubber washer slightly compresses and expands flush with the metal washer edge without cupping or bulging.
- • Black rubber washer is visible as a thin, neat ring flush with the steel washer edge.
- • Screw heads sit perfectly flat and perpendicular against the metal sheet.
- • Over-driving screws, which mushrooms the rubber washer out and creates water-pooling depressions.
- • Under-driving screws, leaving the rubber washer loose and uncompressed.
Apply Lap Sealant and Set Adjacent Panel
Run a continuous bead of butyl tape sealant along the top of the exposed underlap rib of the installed panel. Lift the second panel and position its overlapping rib over the taped underlap, nesting the ribs tightly together. Check that the eave overhang aligns flush with the first panel before securing.
- • Butyl tape is sandwiched completely between the overlapping rib and the underlap rib.
- • The bottom eave edges of both panels form a continuous straight line.
- • Stretching the butyl tape too thin while applying it, leading to voids in the seal.
- • Allowing dirt or sawdust onto the tape before the overlapping panel is dropped.
Fasten Sidelaps and Repeat Sequence Across Roof
Install stitch screws (shorter 3/4-inch lap screws) through the crest of the overlapping rib seam every 12 to 16 inches on center to lock the seam. Fasten the rest of the panel field into the purlins matching the first panel pattern. Repeat the lay-seal-fasten sequence across the roof, verifying squareness every 3 panels.
- • Overlapping rib seams are tight with no bowing or gaps between stitch screws.
- • Uniform grid of screws visible across all installed panels across purlin lines.
- • Skipping periodic squareness checks, resulting in creeping panel alignment across the roof deck.
- • Driving stitch screws off-center, causing them to miss the underlap rib beneath.
Credit: inspired by an original tutorial by ASC Building Products-Metal Roofing & Siding — watch the original on YouTube.
Don’t have everything?
- No Cordless drill with depth-sensing clutch? Standard variable-speed drill with torque collar set to low clutch rating
- No Aviation tin snips? Electric metal cutting shears or nibbler attachment