Edge metal is the cheapest part of a roof and the first part to cost you. It holds the membrane at the perimeter, and the perimeter is where wind starts peeling. The City of Coeur d'Alene sets a 115 mph design wind speed, and the November 2015 windstorm that cut power to about 238,000 customers in the region is the reminder that the edge is tested. A few feet of loose coping can turn into a torn corner and an open roof.
We price edge metal by the linear foot, with the attachment spelled out. Gutters and downspouts get their own lines. The owner sees what each piece costs and what it does.
The Call: Replace Short, Fasten Long
The best edge work replaces what is bent or corroded and re-attaches everything else to a stronger pattern. A new cap on a weak cleat fails in the next storm. A new cleat, set to the right spacing and fastened into solid backing, holds. When we walk a roof, we pull a few fasteners at random along the edge to see what they are in, and the result sets the scope.
The call has three options. Re-secure and reseal where the metal is sound. Replace sections where it is bent, cracked or rusted. Replace the whole run with a heavier profile where the existing metal is thin, fasteners are pulling out or the original design is below current wind requirements. We price each option, and the owner picks.
Testing a few fasteners tells us more than any drawing. If screws turn freely in the backing, the substrate is soft or the fasteners are the wrong length, and a heavier cap would pull out just the same. If the backing is wet or rotted, that is its own line, and it gets fixed first. We record each test location on the roof plan, so a GC or an owner can see the sample behind the scope.
What It Costs: Linear Feet and Lead Time
Edge metal is priced by the linear foot, plus corners, transitions and end caps, each of which is a separate fabricated piece. Gutters follow the same logic, with hangers, outlets, downspouts and straps priced as items. Materials matter. Prefinished steel, aluminum and stainless carry different prices and different lifespans, and thick gauge costs more but resists denting from ice and ladders.
Lead time is where schedules slip. Custom-bent profiles take days to weeks to fabricate, and colors may be special order. A GC who orders edge metal at the start of a reroof avoids a gap at the end. On a repair job, we bend the common profiles ahead of the visit so a failed section can be replaced in one trip. The money saved is the cost of a second mobilization and a second round of temporary protection.
What the Code Sheet Says: Wind, Snow and Ice Barrier
The City of Coeur d'Alene design criteria list a 115 mph design wind speed, a 60 psf ground snow load and a 24 inch frost line, rate weathering as severe and require ice barrier underlayment. Idaho enforces the 2018 International Building Code statewide, and edge metal on a commercial roof is tested and specified for wind uplift under that framework. We match the attachment to the roof, not to a catalog.
The snow load has its own effect on the edge. A slide from a metal roof can shear off a gutter and bend a drip edge. Drift pockets pile weight along a parapet and push meltwater to the coping joints. Ice barrier, where it is called for, protects the first few feet of roof from refreezing meltwater that runs back under the edge. Get the edge detail right and the ice barrier does its job. Get it wrong and water goes behind it. The detail is simple to state: the membrane laps over the edge, the metal covers the lap and the fastener pattern holds it down. Shortcuts show up in the first thaw as a wet stain below the parapet.
Where It Fails First: Joints, Cleats and Corners
Failure starts at the joints. A coping splice opens and lets water into the wall. A cleat pulls out of old substrate and the cap lifts. A corner miter cracks. Sealant dries out after a few seasons and the gap behind it fills with water, which freezes and widens it. Gutters fail at the hangers, which pull away under ice load, and at the outlets, which clog.
We check every joint, every transition and every corner on the perimeter, and we test fasteners by hand. The parapet cap on a tilt-up at Riverbend Commerce Park has long runs with expansion joints, and the corners are where the wind concentrates. An institutional building with several wings has more roof-to-wall transitions, and each is a flashing detail. When a failure has already caused damage, flashing failure repair deals with the water that got in.
Alternates: Gutters, Snow Guards and Heat Cable
A gutter on a snow-heavy building is a decision, not a default. Gutters carry water away from entries and walls, but a snow slide can tear them off. The alternates are separate lines: a heavy-gauge gutter with closer hangers, snow guards on the slope above, heat cable at the outlet, and a downspout extension to keep water off the walk. The owner picks the mix.
On sloped metal roofs, snow guards hold the pack so it melts in small amounts. On low-slope roofs, a scupper through the parapet is often better than a gutter, and we address it with the roof drain scope. In places that get more snow, such as Wallace at about 76 inches a year or Mullan at over 100, we assume the heavier case. Post Falls averages 59 inches, and its buildings need the same attention at a smaller scale.
Closeout: Photos and a Fastener Schedule
At closeout, we give the owner photos of every run before and after, the fastener type and spacing used, the product data for the metal and sealant and a note on what to check each season. The record is short and useful. It shows what the edge was built to resist, and it gives the next crew something to compare against. Where a roof has been recovered, the edge often needs raising to match the new height, which is an extra line the GC should carry at the start.
Edge metal is part of every preventive maintenance walk, and it comes up again after any storm damage event. A roof with a clean edge record gives the owner something to show an insurer or a buyer.
Commercial Roofing Questions
Should I replace or re-secure loose coping?
Re-secure if the metal is sound and the backing is solid. Replace if it is bent, corroded or the fasteners are pulling out.
What lead time should I plan for?
Custom profiles can take days to weeks. Order at the start of a reroof so the metal arrives before the membrane is done. If the metal comes late, the crew finishes the field and leaves the edge open, and an open edge in a Coeur d'Alene fall is a gamble with the first wind. Ordering early is free; waiting costs temporary closures and a second visit.
Do I need gutters?
Not always. They help where water must be kept off an entry. On snow-heavy roofs, they need heavy hangers and often snow guards.
How tight should edge fasteners be spaced?
Closer at corners and the first section of each run. We follow the manufacturer's data and the wind requirement for the roof.
Does sealant alone fix a loose edge?
No. Sealant closes a gap. It does not hold the metal. Fastening does.