STANDING SEAM
METAL ROOFING
The complete guide to standing seam metal roofing — from new construction to installing over existing shingles. Custom-length panels fabricated on-site mean zero horizontal seams, zero leak points, and a 50+ year roof that outlasts everything else on your home.
WHY STANDING SEAM ROOFING?
Standing seam is the gold standard of metal roofing. Unlike exposed fastener systems, standing seam panels interlock with concealed clips — no screws penetrating the roof surface means no potential leak points. When panels are fabricated on-site to the exact length of your roof, there are zero horizontal seams from ridge to eave.
50+ YEAR LIFESPAN
Standing seam metal roofs routinely last 50 to 60 years — two to three times longer than asphalt shingles. Many manufacturers offer 40-year paint warranties and lifetime substrate warranties.
ENERGY EFFICIENT
Metal roofs reflect solar radiant heat, reducing cooling costs by 20 to 40 percent. When installed with Above Sheathing Ventilation (ASV), the air gap further reduces heat transfer into the attic.
100% RECYCLABLE
At end of life, metal roofing is 100 percent recyclable. Most metal roofing contains 25 to 95 percent recycled content. Compare this to asphalt shingles, which contribute 11 million tons to landfills annually in North America.
INSURANCE DISCOUNTS
Many insurance companies offer premium discounts of 10 to 35 percent for homes with metal roofs due to superior resistance to wind (rated to 140+ mph), hail, and fire (Class A non-combustible).
LONG-TERM VALUE
While the upfront cost is higher than shingles, the total cost of ownership over 50 years is significantly lower. No re-roofing every 15 to 20 years, no maintenance, no moss treatments, no granule loss.
ALL-CLIMATE PERFORMANCE
Performs in all BC climates — from coastal rain to interior snow loads to northern cold. Snow slides off the smooth surface, ice dams are virtually eliminated, and the panels handle thermal cycling without cracking.
STANDARD INSTALLATION
For new construction or full tear-off re-roofs, standing seam panels are installed over clean roof decking with underlayment. This is the ideal scenario for maximum performance and longevity.
PREPARE THE DECK
Ensure the roof decking (plywood or OSB) is in good condition, properly fastened, and free of rot or damage. Repair or replace any compromised sections. The deck must be flat and smooth — standing seam panels will telegraph any irregularities in the substrate.
INSTALL UNDERLAYMENT
Roll out synthetic underlayment (such as Sharkskin or equivalent) over the entire roof deck. Overlap seams by 6 inches minimum and tape all seams. Start at the eave and work upward so each course overlaps the one below. In cold climates, install ice and water shield membrane along the eaves extending at least 24 inches past the exterior wall line.
INSTALL EAVE DRIP EDGE AND STARTER
Install a metal drip edge along the eave, extending over the fascia board. This directs water into the gutter and prevents wind-driven rain from getting under the panels. Install the eave starter strip or cleat that will receive the bottom edge of the first panel.
ATTACH CLIPS TO DECK
Fasten standing seam clips to the roof deck at 24-inch intervals along each panel line. Clips should be aligned in straight rows from eave to ridge. Use stainless steel or galvanized screws rated for the expected wind uplift loads. The clips allow panels to expand and contract with temperature changes while remaining securely fastened.
INSTALL FIRST PANEL
Starting at one end of the roof (typically the gable end opposite the prevailing wind direction), engage the first panel into the eave starter and snap it onto the clips. Ensure the panel is square to the eave — this first panel sets the alignment for the entire roof. Use a chalk line or laser level to verify.
CONTINUE PANELS ACROSS ROOF
Each subsequent panel interlocks with the previous one via the standing seam. Snap or mechanically seam each panel depending on the system type. Snap-lock panels simply press together; mechanical seam panels require a hand seamer or electric seaming machine to fold the seam closed. Continue across the roof, checking alignment every few panels.
INSTALL RIDGE CAP AND TRIM
Once all field panels are installed, install the ridge cap along the peak. The ridge cap covers the top ends of the panels and provides a weather-tight seal. Install hip caps, valley flashing, gable trim, and any wall flashing where the roof meets vertical surfaces. All trim should be color-matched to the panels.
SEAL PENETRATIONS
Install flashing boots around all roof penetrations (plumbing vents, exhaust fans, chimneys). Use manufacturer-approved sealant at all trim-to-panel junctions and penetration flashings. Inspect the entire roof from the ground and from on top, checking for any gaps, misaligned panels, or unsealed connections.
METAL OVER EXISTING SHINGLES
In many cases, standing seam metal roofing can be installed directly over existing asphalt shingles without a tear-off. This "recover" method saves significant cost, reduces landfill waste, and provides an additional insulation benefit through the built-in air gap.
HOW IT WORKS
Specialized recover clips are designed to sit on top of the existing shingle surface. These clips have multiple fastener holes that align with the shingle tab pattern, ensuring secure attachment through the shingles into the roof deck below. The clips create a 3/4-inch integrated air space between the old shingles and the new metal panels.
This air space — called Above Sheathing Ventilation (ASV) — is not just dead air. It creates a convective loop that actively vents heat away from the roof deck. Studies have shown that ASV reduces heat transfer through the roof assembly by up to 30 percent, resulting in measurably lower cooling costs.
The existing shingles remain in place as an additional moisture barrier and insulation layer. The new metal roof handles all weather protection duties while the old shingles quietly decompose in place over decades — never reaching a landfill.
RECOVER REQUIREMENTS
COST SAVINGS: RECOVER VS TEAR-OFF
| COST ITEM | TEAR-OFF + NEW METAL | RECOVER (METAL OVER SHINGLES) | SAVINGS |
|---|---|---|---|
| Tear-off labor | $1.50-2.50/sq ft | $0 | $1.50-2.50/sq ft |
| Dumpster and disposal | $500-1,500 | $0 | $500-1,500 |
| New underlayment | $0.50-1.00/sq ft | Not required | $0.50-1.00/sq ft |
| Deck repairs | Often needed | Rarely needed | Variable |
| Total per 2,000 sq ft roof | $3,000-7,000 extra | $0 extra | $3,000-7,000 |
TECHNICAL SPECIFICATIONS
| PARAMETER | SPECIFICATION |
|---|---|
| Panel Width | 12" standing seam profile |
| Panel Material | Galvalume steel (premium residential & commercial) |
| Seam Height | 1" to 1.75" |
| Seam Type | Snap-lock or mechanical seam |
| Panel Length | Custom — fabricated on-site to exact roof measurement |
| Substrate | Galvalume AZ55 (aluminum-zinc alloy coated steel) |
| Yield Strength | 50 ksi minimum |
| Paint System | SMP or PVDF (Kynar 500) — 40-year warranty |
| Clip Spacing | 24" on center typical |
| Minimum Slope (snap-lock) | 3:12 |
| Minimum Slope (mechanical seam) | 1/2:12 |
| Minimum Slope (recover) | 2:12 |
| Wind Rating | UL 580 Class 90 (140+ mph) |
| Fire Rating | Class A (non-combustible) |
| Hail Rating | Class 4 (highest) |
| Weight | 1.0 to 1.5 lbs per square foot |
| Thermal Movement | Approximately 1/8" per 10' per 100°F change |
| Colors Available | 20+ standard colors in SMP and PVDF |
TOOLS & MATERIALS
TOOLS NEEDED
- Drill/impact driver with hex bits
- Tin snips (left, right, and straight cut)
- Nibbler tool (for clean panel cuts)
- Hand seamer or electric seaming machine (for mechanical seam)
- Wuko bender (for trim and flashing bends)
- Portable metal brake (for custom trim fabrication)
- Tape measure (25-foot minimum)
- Chalk line and string line
- Pop rivet gun
- Caulking gun and sealant
- Roofing harness and fall protection equipment
- Ladder and/or scaffolding
- Safety glasses and cut-resistant gloves
MATERIALS LIST
- 12" standing seam panels (custom length to roof measurement)
- Synthetic underlayment (for new construction / tear-off)
- Ice and water shield membrane (for eaves in cold climates)
- Standing seam clips (fixed and floating)
- Eave drip edge and starter strip
- Ridge cap
- Gable trim
- Valley flashing (for intersecting roof planes)
- Wall flashing (where roof meets vertical surfaces)
- Pipe boot flashings (for plumbing vents)
- Color-matched sealant
- Stainless steel or galvanized screws
- Touch-up paint
SAFETY AND IMPORTANT NOTES
- Fall protection is mandatory. Working on roofs is inherently dangerous. Always use a properly rated roofing harness, anchor points, and fall arrest system. Never work on a wet or icy roof. If you are not comfortable working at height, hire a professional.
- Never use abrasive cut-off wheels on panels. The heat destroys the Galvalume coating and the sparks embed in the paint finish, causing premature rust. Use tin snips, a nibbler, or a circular saw with a fine-toothed metal blade.
- Allow for thermal expansion. Metal panels expand approximately 1/8 inch per 10 feet per 100 degrees Fahrenheit of temperature change. Use a combination of fixed and floating clips to allow panels to move. Never over-tighten fasteners.
- Check local building codes. Permits may be required for roofing work. Some jurisdictions limit the number of roof layers (typically 2 maximum). Verify requirements with your local building authority before starting.
- Consider snow guards in heavy snow areas. Metal roofs shed snow very efficiently — sometimes too efficiently. In areas with heavy snowfall, install snow guards or snow rails to prevent sudden snow avalanches that can damage gutters, landscaping, or injure people below.
FREQUENTLY ASKED QUESTIONS
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We fabricate 12-inch standing seam panels on-site to the exact length of your roof. No horizontal seams, no leak points, no factory limitations. No job too big or small.