System Overview
Metal roofing has evolved from simple agricultural buildings to premium residential and commercial applications. Modern metal roofing systems offer exceptional durability (40-70 years), energy efficiency, and fire resistance. They are increasingly popular for both new construction and re-roofing projects.
As an estimator, understanding the distinctions between standing seam, exposed fastener panels, and specialty metal systems is critical. Material costs, labor rates, and installation complexity vary dramatically between system types. Metal roofing requires specialized crews, precise measurements, and attention to thermal movement details.
Pro Tip: Metal roofing requires expansion/contraction details for thermal movement. Panels can expand/contract up to 1 inch per 100 feet with temperature changes. Missing these details leads to oil-canning, fastener pullout, and warranty issues.
Metal Roof Types
Standing Seam Metal Roofing
The premium metal roofing system. Vertical panels with concealed fasteners and raised seams create a clean, modern appearance. Clips allow thermal movement while maintaining watertight integrity. Most common for commercial and high-end residential projects.
12 inch, 16 inch, 18 inch coverage
1 inch, 1.5 inch, 2 inch, 3 inch
Galvalume, aluminum, copper, zinc
24 ga (residential), 22 ga (commercial)
$2.50-6.00/SF (panel only)
3.0-5.0 hours/square
- • Clean appearance - no exposed fasteners
- • Concealed clips allow thermal movement
- • Superior wind and weather resistance
- • Longest lifespan (50-70 years)
- • Can accommodate solar panel attachments
Exposed Fastener Metal Panels (R-Panel, PBR)
Economical metal roofing where panels are screwed directly to purlins or decking. Fasteners with neoprene washers penetrate the panel face. Popular for agricultural, industrial, and budget-conscious projects.
R-Panel (36 inch), PBR (26 inch), 7.2 panel
3/4 inch to 1.25 inch
Galvanized, Galvalume, painted steel
26 ga, 29 ga (most common)
$0.80-2.00/SF (panel only)
2.0-3.5 hours/square
- • Fastener maintenance required (washers deteriorate)
- • Thermal movement can cause fastener loosening
- • Less aesthetic appeal than standing seam
- • Lower cost makes it popular for barns, shops, sheds
- • 30-40 year lifespan typical
Corrugated Metal Panels
Classic wavy profile with repeating rounded or angular ribs. Economical and quick to install. Common for agricultural buildings, sheds, and industrial applications.
26 inch, 36 inch coverage
2.67 inch (standard)
$0.75-1.80/SF
1.8-3.0 hours/square
Metal Shingles & Tiles
Stamped metal panels designed to replicate traditional roofing materials like slate, wood shake, or clay tile. Premium residential product combining metal durability with traditional aesthetics.
Slate profile, shake profile, tile profile
Steel, aluminum, copper, zinc
$3.00-8.00/SF
4.0-6.0 hours/square
Note: Metal shingles require extensive trim work, custom fabrication, and skilled labor. Labor costs often exceed material costs.
Materials & Components
A complete metal roof system includes far more than just panels. Underlayment, fasteners, trim, closures, and flashings are critical to performance and waterproofing.
1. Underlayment
Required under all metal roofing to prevent condensation damage and provide secondary water barrier. Critical for noise reduction and thermal performance.
$30-50 per square, slip-resistant
$50-80 per square, dark metal roofs
Critical: Dark metal roofs can reach 180°F. Standard felt will deteriorate. Use high-temperature synthetic underlayment rated for 250°F+.
2. Fasteners & Clips
Fastener type and quantity vary dramatically between exposed fastener and concealed clip systems.
3. Trim & Flashing
Custom-fabricated or pre-formed metal trim pieces for edges, transitions, and penetrations. Often represents 20-30% of material cost.
Note: Trim must match panel material (steel trim on steel panels, aluminum on aluminum). Mixing metals causes galvanic corrosion.
4. Closure Strips & Foam Fillers
Profile-matched foam strips seal gaps at eaves and ridges to prevent insect, bird, and weather infiltration.
5. Sealants & Butyl Tape
Critical for watertight seams, end laps, and penetration sealing. Metal roofing lives or dies by proper sealant application.
6. Ventilation Components
Metal roofs require proper attic ventilation. Ridge vents, gable vents, or continuous soffit intake must be included.
Estimation Considerations
Panel Run Length
Standing seam panels can be manufactured in continuous lengths up to 40-50 feet. Longer runs reduce seams but increase handling difficulty and waste.
Roof Pitch Impact
Steeper roofs require safety equipment, slower installation, and potentially shorter panel lengths for safe handling.
Deck Type
Solid decking (plywood/OSB) vs. open framing with purlins dramatically affects installation approach and cost.
Complexity & Trim
Dormers, valleys, multiple roof planes, and skylights significantly increase trim fabrication and labor time.
Material Takeoff Details
Step-by-Step Takeoff Process
Metal roofing follows roof plane, so pitch multiplier is essential. Measure horizontal footprint and apply multiplier.
Determine panel coverage width and calculate number of panels needed. Add waste for cuts and errors.
Metal roofing requires extensive trim. Measure eaves, rakes, ridges, hips, valleys, walls, and transitions separately.
Standing seam uses concealed clips. Exposed fastener panels use screws with washers.
Underlayment covers entire roof area. Add closure strips, butyl tape, and sealant.
Each roof penetration requires a boot, flashing, or custom detail. Count and price individually.
Critical: Metal panels are ordered by coverage width, not actual width. A 16 inch coverage panel might be 18 inches actual width with 2 inches of overlap. Always verify coverage vs. actual dimensions with manufacturer.
Labor Estimation Guidance
Metal roofing labor rates are heavily influenced by system type, roof complexity, and crew experience. Standing seam requires specialized training and equipment. Budget for learning curve on first few projects.
Baseline Productivity Rates
| Task | Hours/Square | Crew Size | Notes |
|---|---|---|---|
| Tearoff (if required) | 1.0-2.0 | 3-4 | Metal over existing roof common |
| Underlayment install | 0.3-0.5 | 2 | Required for warranty |
| Standing seam panels | 3.0-5.0 | 2-3 | Includes clip installation |
| Exposed fastener panels | 2.0-3.5 | 2-3 | Faster than standing seam |
| Corrugated panels | 1.8-3.0 | 2-3 | Fastest panel type |
| Metal shingles/tiles | 4.0-6.0 | 2 | Most labor intensive |
| Trim fabrication & install | Variable | 1-2 | $3-8 per LF installed |
| Ridge cap install | - | 2 | 0.3-0.5 hrs per LF |
Factors That Speed Up Work:
- • Long, uninterrupted panel runs
- • Simple gable or shed roof
- • Pre-cut panels to exact length
- • Experienced metal roofing crew
- • Good weather (dry, low wind)
- • Easy material access
- • Low to moderate pitch (3/12-6/12)
Factors That Slow Down Work:
- • Multiple roof planes and levels
- • Extensive valleys and dormers
- • Custom trim fabrication on-site
- • Steep pitch (8/12+) requires safety gear
- • Windy conditions (cannot install)
- • Numerous penetrations
- • Inexperienced crew with metal
Example Labor Calculation
Common Estimating Mistakes
1. Forgetting Trim and Accessories
Panels are only 60-70% of total material cost. Trim, fasteners, underlayment, and accessories add significant cost. Missing these items destroys profitability.
Fix: Create detailed trim takeoff for eaves, rakes, ridges, valleys, walls. Budget $2-4/SF for standing seam trim, $1-2/SF for exposed fastener trim.
2. Underestimating Labor for Trim Work
Custom trim fabrication and installation is time-consuming. Valley flashing, wall flashings, and complex transitions can take longer than panel installation.
Fix: Budget trim labor separately from panel labor. Complex roofs: trim labor equals or exceeds panel installation labor.
3. Wrong Panel Coverage Width
Confusing actual panel width with coverage width leads to ordering 10-15% too few panels. A 16 inch coverage panel is 18+ inches actual width.
Fix: Always use coverage width for calculations. Verify with manufacturer cut sheets. For 16 inch coverage: divide roof width by 1.33 ft (16 inch = 1.33 ft).
4. Not Including High-Temp Underlayment
Dark metal roofs reach 180°F in summer. Standard felt underlayment deteriorates rapidly, voiding warranties and causing odor problems.
Fix: Always spec high-temperature synthetic underlayment (250°F rated) for metal roofing, especially dark colors. Add $20-30/square to material cost.
5. Missing Closure Strips and Sealants
Foam closures at eaves and ridges are essential to keep out pests, wind-driven rain, and snow. Butyl tape at end laps is required for waterproofing.
Fix: Include eave closure (entire perimeter), ridge closure (all peaks), butyl tape (all panel end laps), and sealant tubes (1 per 4 squares minimum).
6. Ignoring Thermal Movement Details
Metal expands and contracts significantly. Fixed fasteners or improperly installed clips lead to oil-canning, fastener pullout, and leaks.
Fix: For standing seam, use floating clips that allow movement. For exposed fastener, use oversize holes and do not overtighten screws. Never lock down thermal movement.
Key Takeaways
- ✓Standing seam is premium system with concealed fasteners - higher cost but superior performance
- ✓Trim and accessories represent 30-40% of material cost - never overlook in estimates
- ✓Use coverage width, not actual panel width, for calculating panel quantity
- ✓High-temperature underlayment is required for dark metal roofs and warranty compliance
- ✓Labor varies dramatically by system type - standing seam is 50-100% more labor than exposed fastener
Get the Complete Metal Roofing Estimating Template
Excel-based template with panel calculators for all metal roof types, trim takeoff worksheets, coverage width converters, clip/fastener calculators, and detailed labor breakdowns for standing seam, exposed fastener, and corrugated systems.
Template Includes:
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