Commercial metal roofing in Denver: standing seam, panels and retrofits

Structural vs architectural metal panels

"Metal roof" covers several very different systems. The first question on any metal project is which kind you have, because it decides what the roof can do, what slope it needs and how it should be repaired.

Getting this wrong is expensive. An architectural panel installed on a slope too low for it will leak at the seams no matter how much sealant goes on, and a structural roof repaired with exposed screws through the seams can bind panels that are designed to move.

Fastener and sealant failures

Metal panels themselves rarely wear out first. The small parts that hold them together and seal them do. Denver's climate makes that worse: strong UV at altitude breaks down rubber and sealants, and big daily temperature swings make panels expand and contract against every fastener.

• Backed-out screws. Thermal movement works exposed fasteners loose over time. A loose screw lets the washer lift and water follows the threads into the building.
• Failed washers. The rubber washers under exposed screws dry out and crack in the sun. Overdriven screws crush them; underdriven screws never sealed in the first place.
• Dried-out lap sealant. Side laps and end laps on exposed-fastener panels depend on sealant tape or caulk that hardens with age, letting wind-driven rain and snowmelt in.
• Closures and trim. Ridge, eave and wall closures that are missing or deteriorated let in water, snow and birds. Loose trim also catches chinook winds.
• Penetrations. Pipe boots, curbs and rooftop equipment supports are frequent leak points, especially where they cross a panel seam or sit in the path of sliding snow.
• Corrosion. Rust starts at cut edges, scratches and fastener holes, and wherever dissimilar metals touch or water from copper runs onto steel or aluminum.

On standing seam roofs, the clips matter too. Panels are meant to slide on their clips as they expand. Clips that were fixed when they should float, or panels pinned by later repairs, can tear at fastener points or buckle. We check that before recommending sealant as the answer.

Hail on metal roofs, and the cosmetic-damage question

Hail season along the Front Range runs from mid-April to mid-August, and metal roofs show it. Hail dents panels, flattens ribs and can crack the coatings on painted metal. Large hail can damage seams, fasteners and trim enough to cause leaks. Smaller hail often leaves a roof covered in dents that are visible from the ground but don't let any water in.

That distinction matters for your insurance. Many commercial property policies include a cosmetic damage exclusion or endorsement for metal roofing, which limits coverage to damage that affects the roof's function, such as its ability to keep water out, rather than its appearance. Policies vary widely, so read yours with your agent or broker, ideally at renewal and before the next storm.

After a hailstorm, we document the roof in a way that's useful whatever your policy says:

• Dent size and density, photographed with a scale on each roof section
• Damage to seams, clips, fasteners, closures, trim and flashings
• Cracked or chipped paint finishes, which can lead to corrosion
• Collateral damage to gutters, vents and rooftop units
• The storm date, and any active leaks traced to their source

For associations and portfolios, we can document every building and meet the adjuster on the roof. We follow Colorado's roofing contract rules: we provide a written contract, and we never pay, waive or rebate a deductible. More on the process is in our association claims guide and after-a-hailstorm checklist.

Snow retention and snow guards

Metal is slick. On a sunny Denver morning after a storm, a full roof of snow can release at once and slide off in a single sheet. That's a hazard to people at entrances and walkways, to parked cars, to gas meters and to lower roofs, and it can tear off gutters, vent pipes and trim on the way down.

Snow retention holds the snow in place so it melts off gradually. A good system is designed, not just installed:

• Type. Individual pad-style guards or continuous bar and fence systems, chosen for the panel, the slope and the amount of snow the roof sees.
• Attachment. On standing seam, clamps grip the seams without puncturing the panels, which preserves watertightness and many manufacturer warranties. Exposed-fastener panels need attachments designed for that profile.
• Layout. The number of rows and their spacing depend on the design roof snow load for your jurisdiction, the roof slope, the panel length and what's below the eave.
• Priorities. We focus first on entrances, walkways, drive aisles, parking and anything fragile at the eave.

Retained snow puts more load on the roof structure and can lead to ice at the eaves, so retention isn't always the right answer everywhere on a roof. We'll explain where it belongs and where it doesn't.

Repair, restoration and retrofit options

Most aging metal roofs don't need to be torn off. The structure and panels are often sound long after the fasteners and sealants are spent, which gives you options:

1. Targeted repairs

   Replace backed-out or failed fasteners with oversized replacements, reseal laps and trim, rebuild penetration flashings and replace damaged panels.

2. Restoration coating

   For exposed-fastener roofs: clean, treat rust, replace or seal fasteners, reinforce seams, then apply an elastomeric coating system. Coatings renew the surface and add reflectivity, and some systems can carry a manufacturer warranty.

3. Spray foam recover

   On low-slope metal buildings, spray foam fills the panel profile, seals every fastener and seam, and adds insulation, finished with a protective coating.

4. Retrofit framing and new panels

   A new standing seam roof installed over the old one on new sub-framing. It can change the slope, add insulation and avoid tearing the old roof off over occupants.

5. Replacement

   Full removal when panels are badly corroded, the structure needs work, or the building's use has changed enough that a different system makes more sense.

Metal on multifamily and mixed-use buildings

On apartments, condos, townhome communities and mixed-use buildings, metal often shows up as a feature rather than the main roof: standing seam mansards and towers, entry canopies, bay roofs, balcony covers, carports and accent roofs that tie into a low-slope roof behind them. Those transitions between metal and membrane are a common source of leaks, and they need a contractor comfortable with both.

Association and mixed-use work brings its own considerations:

• Appearance. Panel profile, color and finish often need board or architectural committee approval, and matching existing panels on a partial replacement takes care.
• Snow over people. Entries, sidewalks, parking and patios sit right under metal eaves. Snow retention is usually a priority.
• Occupied buildings. Residents and tenants stay in place. We give notice before noisy work, keep walkways protected and clean up daily.
• Planning. We can phase work across buildings to match reserves and give boards the condition notes they need for reserve planning.

Our HOA and multifamily page covers how we work with boards and community managers. As a general contractor first, we're also used to working as the roofing subcontractor on mixed-use projects for general contractors.

Maintaining a metal roof

Metal roofs need less attention than most systems, but not none. A twice-a-year visit through our S.M.a.R.T. program, plus a check after severe weather, should cover fastener and sealant condition, closures and trim, penetration flashings, gutters and downspouts, snow guards and any new corrosion. Each visit ends with a written report with photos.

Metal roofing FAQs