Before You Start

Skill Level: Expert (Professional STRONGLY recommended)

Time Required: 3-5 days for average home (1,500 sq ft roof)

Cost: $15,000-20,000 in materials + equipment rental (DIY) vs. $25,000-35,000 (professional installation)

Required Specialized Equipment

Panel Fabrication:

• Portable panel bender/roll former ($5,000-15,000 to purchase, $500-1,000/week to rent)
• Metal brake (for trim fabrication)
• Panel cutter or metal shears

Installation Tools:

• Manual or electric seamer (for joining panels)
• Cordless drill with hex head bits
• Rivet gun (for trim attachment)
• Hemming tool
• Chalk line
• Tape measure (50-100 ft)
• Tin snips (straight, left, right)
• Pop rivet tool

Safety Equipment:

• Fall protection harness and rope (MANDATORY)
• Cut-resistant gloves (metal edges are razor-sharp)
• Safety glasses
• Soft-soled shoes (metal is slippery)
• Knee pads

Materials Needed

• 24-gauge steel coil (Kynar 500 or SMP finish)
• Synthetic underlayment (high-temp rated for metal)
• Ice & water shield (for eaves and valleys)
• Eave trim (drip edge)
• Rake trim (gable trim)
• Ridge cap (ventilated or non-ventilated)
• Valley trim (if applicable)
• Clips (for panel attachment - concealed fastener system)
• Screws (stainless steel, painted to match)
• Butyl tape sealant
• Closure strips (for ridge and eave)

Step 1: Prepare Roof Deck

Deck Requirements:

• Minimum 7/16" OSB or 1/2" plywood
• Smooth, clean, dry surface
• No protruding nails or screws
• Structurally sound (no soft spots or rot)

Process:

1. Remove old roofing: Metal can be installed over shingles in some cases, but tear-off is recommended
2. Inspect deck: Replace any damaged sections
3. Ensure proper slope: Minimum 3:12 pitch for standing seam (2:12 with special seam sealant)

Step 2: Install Underlayment

Why This Matters:

Metal roofs can reach 150°F+ in summer. Use high-temp synthetic underlayment rated for metal roofing.

Installation:

1. Apply ice & water shield at eaves: 36-72 inches (code minimum 36", we recommend 72" in Hope/Harrison)
2. Install synthetic underlayment: Horizontal courses, 6-inch overlap
3. Use high-temp rated product: Standard underlayment can melt under metal in summer
4. Smooth and flat: Wrinkles will telegraph through metal

Step 3: Install Eave Trim (Drip Edge)

Critical: Eave trim must be installed BEFORE panels.

Installation:

1. Measure and cut: Custom-fabricate to match panel profile
2. Install with clips or screws: Every 12-18 inches
3. Overlap 2 inches: Where pieces meet
4. Seal laps: With butyl tape
5. Ensure proper overhang: 1-2 inches past fascia into gutter

Step 4: Install Rake Trim (Gable Trim)

Installation:

1. Custom-fabricate: To match panel profile and provide weather seal
2. Install before panels: Panels will slide under rake trim
3. Fasten securely: Screws every 12 inches
4. Seal with butyl tape: Where trim meets deck

Step 5: Install Valley Trim (If Applicable)

Open Valley Method (Recommended for Metal):

1. Fabricate valley trim: 24-36 inches wide, matching metal gauge
2. Center in valley: Equal width on each side
3. Fasten edges only: Allow for thermal expansion
4. Overlap upslope: 12 inches where pieces meet
5. Seal laps: With butyl tape

Step 6: Establish Panel Layout

Critical Planning:

Panel layout determines aesthetics and performance. Poor planning results in narrow panels at rakes (looks bad).

Process:

1. Measure roof width: From rake to rake
2. Determine panel coverage: Typically 12-16 inches per panel
3. Calculate number of panels: Roof width ÷ panel coverage
4. Adjust for symmetry: Ensure panels at both rakes are similar width (minimum 6 inches)
5. Mark panel locations: Snap chalk lines for clip placement

Step 7: Fabricate Panels

Panel Length:

• Measure from eave to ridge (plus overhang)
• Add 2-3 inches for eave overhang
• Panels can be fabricated up to 40+ feet long (eliminates horizontal seams)

Fabrication:

1. Load coil into panel bender: Follow manufacturer instructions
2. Set panel width: Typically 12-16 inches
3. Feed coil through machine: Machine forms standing seam profile
4. Cut to length: At eave end (ridge end cut after installation)
5. Handle carefully: Panels dent easily, edges are sharp

Step 8: Install Clips

Why This Matters:

Clips allow panels to expand/contract with temperature changes while staying secured. This is what makes standing seam superior to exposed-fastener systems.

Installation:

1. Follow chalk lines: Clips align with panel seams
2. Spacing: 12-24 inches on center (check manufacturer specs)
3. Fasten to deck: With screws (not nails)
4. Ensure proper alignment: Clips must be straight for panels to install correctly

Step 9: Install First Panel

Critical First Panel:

If the first panel isn't straight, every subsequent panel will be crooked.

Installation:

1. Position at rake: Align with rake trim
2. Check for square: Measure from eave to multiple points along panel
3. Engage clips: Slide panel female leg over clips
4. Fasten at eave: Screw through panel flange at eave (only location with exposed fasteners)
5. Verify alignment: Before installing second panel

Step 10: Install Subsequent Panels

Process:

1. Position next panel: Align male leg with previous panel's female leg
2. Engage clips: Slide panel over clips
3. Seam panels together: Use manual or electric seamer to fold seam
4. Work carefully: Seaming is permanent - mistakes are expensive
5. Check alignment: Every 2-3 panels

Step 11: Seam Panels

Seaming Process:

1. Start at eave: Work upward toward ridge
2. Use seamer tool: Manual or electric (electric is faster, manual gives more control)
3. Make multiple passes: Typically 2-3 passes to fully close seam
4. Maintain consistent pressure: Uneven seaming causes leaks
5. Inspect seam: Should be tight, uniform, no gaps

Step 12: Install Ridge Cap

Options:

• Ventilated Ridge Cap: Allows attic ventilation (recommended)
• Non-Ventilated Ridge Cap: Solid cap (use if ventilation handled elsewhere)

Installation:

1. Trim panels at ridge: Leave 1-2 inch gap for ventilation
2. Install closure strips: Foam or rubber strips that match panel profile
3. Position ridge cap: Center over ridge
4. Fasten through cap: Screws with rubber washers every 12 inches
5. Overlap end caps: 2 inches where pieces meet
6. Seal end caps: With butyl tape or sealant

Step 13: Flash Penetrations

Plumbing Vents:

1. Use metal pipe boot: Matches roof material
2. Cut panel around pipe: Tight fit (within 1/4 inch)
3. Install boot: Slide over pipe, fasten flange
4. Seal with butyl tape: Around pipe and under flange

Chimneys:

1. Install base flashing: At chimney base
2. Install step flashing: One piece per panel rib
3. Install counter flashing: Embedded in mortar, overlaps step flashing
4. Seal all laps: With butyl tape

Step 14: Install Trim and Accessories

Final Touches:

• End wall flashing: Where roof meets vertical wall
• Headwall flashing: Where roof meets wall at upper end
• Sidewall flashing: Along roof-to-wall transitions
• Gable trim: Covers panel edges at rakes

Critical Installation Details

Thermal Expansion:

Metal expands/contracts significantly with temperature. A 40-foot panel can expand/contract 1/2 inch or more. Clips allow this movement. NEVER fasten panels rigidly except at eave.

Fastener Selection:

• Use stainless steel screws (painted to match roof)
• Screws must have rubber EPDM washers
• Never use nails (they back out with thermal cycling)

Sealant:

• Use butyl tape (not silicone or polyurethane)
• Butyl remains flexible and adheres to metal
• Apply generously at all laps and penetrations

Common Mistakes to Avoid

1. Over-Fastening

Fastening panels rigidly prevents thermal expansion and causes "oil-canning" (wavy appearance).

2. Improper Seaming

Incomplete or uneven seaming causes leaks. Seams must be tight and uniform.

3. Walking on Panels

Walking on panel flats causes dents. Walk on seams or use walk boards.

4. Inadequate Slope

Installing on roofs flatter than 3:12 without special seam sealant causes leaks.

5. Mixing Metals

Using incompatible metals (e.g., steel screws on aluminum panels) causes galvanic corrosion.

The Bottom Line

Standing seam metal roofing is a premium product that requires professional installation. The specialized equipment, technical knowledge, and experience required make this a poor DIY project for most homeowners.

At RJ Roofing Bros, we have the equipment, training, and experience to install standing seam metal roofing correctly. We're certified installers for Westform and other manufacturers. The warranty protection and quality assurance are worth the professional installation cost.

Want a metal roof done right? Call (604) 997-1292 for a free quote.