Ask five roofers how to install a metal roof and you will get six answers. The fundamentals rarely change, yet the details make or break performance. A ridge that looks straight from the ground can walk by an inch over 40 feet. A fastener driven a quarter turn too tight can dimple a panel and invite a leak a year later. After two decades working with residential metal roofing and commercial metal roofing, here is a practical, field-tested walkthrough of new metal roof installation that covers the process from evaluation to final inspection, plus the decisions that matter along the way.
Where a metal roof makes sense
Not every building should get metal. It does its best work on roofs with clean planes, sufficient pitch, and long-term owners who value durability. On a 4:12 or greater slope, standing seam shines. Corrugated profiles handle 3:12 and, with careful detailing and underlayment choices, even 2:12, though most metal roofing contractors become picky at lower slopes to avoid capillary surprises. Large commercial roofs with low pitch often move toward mechanically seamed standing seam with continuous clips and a high-temp underlayment. Small bungalows do just fine with snap-lock panels, provided the eaves and valleys are flashed correctly.
Owners frequently ask about noise. In practice, a metal roof over a proper deck, synthetic underlayment, and attic insulation is not louder than shingles in a rainstorm. The tin-roof-on-purlins sound comes from open framing, not from the metal itself. Another common concern is lightning. Metal does not attract strikes, but it is non-combustible, which improves the roof’s performance if the building is struck.
The pre-install assessment that saves headaches
Good metal roofing services begin with a roof inspection that goes deeper than surface measurements. For existing homes, I look at three things before I write a proposal: structure, ventilation, and water paths.
Structure comes first. A metal roof weighs about 1 to 1.5 pounds per square foot for most steel panels, lighter than shingles by a wide margin. Weight rarely poses a problem, but we check decking for rot, dips along rafters, and deflection near ridge beams and hips. I run a string line across long spans. Any noticeable sag guides the layout and may require shimming or deck repairs.
Ventilation matters because metal installs are tight. If the attic traps moisture, condensation will find the coldest surfaces. I check soffit intakes, baffles, and exhaust strategy. Many homes need a continuous ridge vent combined with open soffits. Skip that, and even a perfect panel install will battle attic moisture that mimics a roof leak.
Finally, I map water. Where does snow drift, where does ice form, how does water cross valleys in heavy wind? Chimney saddles, dead valleys, and intersecting additions are typical leak zones. A thoughtful chimney cricket, wider valley metal, or a diverter at just the right spot makes years of difference.
Choosing materials with intent
You can install metal well only when the chosen system fits the building, climate, and budget. The three main decisions are profile, metal, and coatings.
Standing seam offers clean lines and hidden fasteners. For most residential metal roofing, snap-lock with 1 to 1.75 inch seams performs beautifully on moderate slopes with runs under 40 feet. Mechanically seamed systems lock tighter and tolerate lower slopes or long runs, which suits commercial metal roofing and coastal wind zones.
Exposed fastener panels, often called AG or R panels, cost less and install faster. They work for barns, shops, and some homes, but they require disciplined fastener layout and periodic maintenance since fasteners remain exposed to UV and thermal movement. If you go this route, expect to budget for metal roofing repair service every 10 to 15 years to replace gaskets or back out and re-seat fasteners.
As for the metal itself, 26 and 24 gauge galvanized or Galvalume steel covers most projects. Thicker 24 gauge resists oil canning and denting better, especially on wide, flat pans. In coastal or chemical environments, aluminum or even zinc may earn their cost by resisting corrosion, provided the installer respects their different expansion rates and fastener choices. Copper is gorgeous and long-lived, but it demands experience and a client comfortable with patina and premium pricing.
Coatings matter more than marketing suggests. PVDF finishes such as Kynar 500 provide better color retention than SMP in strong sun. On a south-facing facade in the Rockies or the Gulf Coast, that difference shows after a decade. For dark colors in hot climates, cool roof pigments can reduce surface temperatures by 30 to 50 degrees on sunny days, which lowers attic heat gain and helps HVAC efficiency.
Tear-off or roof-over: calling it right
A new metal roof installation often prompts the question: can we install over existing shingles? The answer rests on code, manufacturer guidelines, and the condition of the old roof. Many jurisdictions allow one recover layer over a single layer of shingles, as long as the deck is sound and flashings can be replaced properly. Roofing over saves disposal cost and keeps the home drier if weather rolls in mid-project.
That said, I recommend tear-off when shingles are brittle, when the deck shows soft spots, or when the roof has complex penetrations. Valleys and sidewall flashing are hard to do right over old material. A tear-off exposes the deck, lets us fasten panels directly to wood, and clears the way for a continuous underlayment and clean flashings. On high-value residential metal roofing, that clarity is worth the extra day.
Preparing the site and the deck
A tidy jobsite keeps the project on schedule and neighbors calm. We protect landscaping with breathable mesh sheets, not plastic tarps that scorch lawns in summer. Dump trailers or bins sit off the driveway if possible, and we roll magnet sweepers at the end of each day. Inside the house, I warn clients about vibration and dust, especially if the attic houses a nursery or a home office.
Once the old roof is off, the deck gets a careful scan. I replace any soft or delaminated sheathing, then fasten loose panels with ring-shank nails or screws set flush. For houses from the 60s or earlier, plank decks are common. Gaps between boards demand a quality synthetic underlayment to bridge and stiffen the surface. If the roof is going to see temperatures above 200 degrees under dark metal, I prefer a high-temperature, self-adhered membrane for valleys, eaves, and around penetrations before rolling the main underlayment.
Underlayment, ice protection, and ventilation details
Underlayment is not just a placeholder before metal goes on. It is a secondary water barrier and a thermal buffer that reduces panel abrasion and noise. We run a peel-and-stick membrane from the eave up at least 24 inches inside the warm wall for ice dam protection in cold climates. Valleys, dead valleys, and lower-slope transitions get peel-and-stick as well. Over the rest, a synthetic underlayment rated for high temperatures keeps its grip and thickness under metal.
Ventilation ties into underlayment choices. If the attic already breathes well through soffits and a ridge vent, the roof deck stays dry. If not, we either correct the attic ventilation or, in some cases, install a vented nail base or counter-batten system to create an above-sheathing ventilation channel under the panels. That approach cools the roof surface and dries out incidental moisture, but it adds height at eaves and gables, which affects trim details. It is a judgment call with real trade-offs.
Flashings at eaves, rakes, valleys, and walls
Flashings are the grammar of a metal roof. Get the syntax right, and the system reads cleanly from eave to ridge with no stops where water can stumble.
Eave trim sets the line. I install a drip edge with a hem that hooks the panel’s bottom lock, backed by underlayment that laps over the metal. On snow country projects, an eave starter with a small kick helps toss meltwater away from fascia and limits staining.
Valleys carry volume. I like open valleys with W-style or ribbed valley metal. The extra center rib breaks surface tension and keeps water from skipping across to the opposite side in heavy flows. Closed valleys with panel-to-panel interlocks look sleek, but they demand perfect panel alignment and are less forgiving if debris nests along the seam.
Sidewalls and headwalls are classic leak sources. Under-siding sidewall flashing, combined with a surface Z-flashing under the panel rib, gives two planes of defense. At headwalls, a tight counterflashing tucked behind siding or stucco and sealed to the wall’s weather barrier prevents backflow. Chimneys need a cricket when they are wider than about 24 inches, or when snow and debris can stack upwind. A well-made cricket sheds water before it thinks about pooling.
Panel layout and handling
Metal panels magnify small layout errors. I start with a control line snapped square to the eave that splits the roof face into equal panel runs so that narrow slivers don’t land at a hip or against a wall. If the ridge is out of parallel with the eave by half an inch over 30 feet, we split that difference over the panel field so the eye never catches a creeping rib.
Oil canning, the subtle waviness in flat pans, is a reality with metal. Heavier gauge, narrower pans, striations, or bead stiffeners help. So does careful handling. Panels should ride on padded saw horses, not gravel. We carry them by the edges, upright, and avoid twisting. On hot days, we stage panels in the shade or install early because warm metal moves differently, and fastening can lock in tension.
For standing seam, clip choice matters. Fixed clips suit shorter runs and stable environments. Floating clips with slotted holes or sliding mechanisms allow expansion on long runs or wide temperature swings. Steel moves roughly 1/8 inch per 20 feet for a 100 degree temperature change. That does not sound like much until the panels bind against a ridge and pucker the pans.
Cutting, seaming, and fastening with care
Every metal roof lives or dies on the quality of its cuts and seams. I avoid abrasive wheels on coated panels because they char the finish and throw hot metal dust that rusts. Instead, we use double-cut shears, nibblers, or a track shear. For field notching and hem bends, a well-sharpened pair of snips and a bending tool keep edges clean.
Snap-lock standing seam looks simple, but the hem folds at eaves, the rib notches at hips, and the clip spacing all influence how the panels sit. I space clips closer near edges and high-wind zones. Fastener choice follows the substrate: screws that bite firmly into decking with a corrosion-resistant coating, sized so the threads grab mostly wood, not air. Over-driving a screw dimples the panel. Under-driving lifts the gasket off the metal and invites capillary water. The right torque falls into your hand with practice, and every installer should test on scrap before committing to the roof.
Exposed fastener panels require even more discipline. Rows must run straight, and screws should land on high ribs where the gaskets shed water best, unless the panel design calls for fastening in the flats per manufacturer requirements. I date the first handful of screws on the packaging and keep a record for future metal roofing repair. Ten years later, when a client calls about a drip, that small note points us to the right replacement gaskets and gives a sense of expected aging.
Penetrations, skylights, and tricky intersections
Any hole through a metal roof deserves a careful detail. Round penetrations, such as vent pipes, can be sealed with high-temperature silicone boot flashings that match the panel ribs. The boot sits on a base with flexible aluminum that forms to the panel profile. If the pipe lands on a rib, a field-built curb or relocation is better than forcing a boot to bridge the rib.
Skylights need curb-mounted units that sit above the panel plane, with cricket diverters on the upslope side. A low-profile skylight that worked under shingles often sits too low for metal and creates a snow trap. I advise clients either to upgrade to a taller curb or to remove and deck over skylights that have reached the end of their service life. It costs less and looks better than band-aiding a chronic leak point.
Dormers add charm and complexity. Where roofs meet walls and valleys converge, we slow down and dry-fit the metal flashings. On one Victorian we renovated, a bull-nosed dormer cheek met a 16-inch panel in a way that defied factory flashings. We templated in cardboard, transferred the pattern to coated coil stock, and fabricated a three-bend counterflashing that disappeared under the cedar shingles. It took an afternoon but saved years of callbacks.
Ridge caps, hips, and snow management
At the top, ridge details finish the system and breathe the attic. Many standing seam systems use a vented Z closure with mesh that keeps out insects and driven snow, while allowing airflow under the ridge cap. The Z sets back from the panel rib to create a clean line and minimize exposed fasteners. In hurricane regions, mechanical attachment and sealant beads at specific points become mandatory, and it is worth reading both code and the panel’s technical manual before starting.
Hips take patience. Each panel gets cut and hemmed to meet the hip line, then tucked under a hip cap with foam or metal closures. An extra hour of layout here prevents creeping reveals that the eye catches from the street. On steep roofs, we install safety anchors at ridge points before the cap goes on. Those anchors double as tie-off points for future metal roofing repair.
Snow retention turns a pretty roof into a safe one in snow country. Smooth metal sheds quickly, and a sudden slide can tear off gutters or damage an entry. I prefer continuous snow rails attached to the panel ribs or clips, not the flats, and designed to match the roof color. Placement follows load calculations rather than guesswork. On commercial entries, a second rail above the first often protects high-traffic doors. The decision belongs in the initial proposal, not as an afterthought.
Sealing and finishing touches
Sealants should be a secondary defense, not the primary one. Wherever possible, we rely on hems, laps, and mechanical interlocks to move water downhill. When sealant is appropriate, it must be compatible with the panel coating and rated for the temperatures it will see. Butyl tape at panel laps and closures, high-temp silicone at penetrations, and polyurethane-based sealants where movement is minimal all have roles. I remind crews that a pretty bead of the wrong sealant fails faster than a hidden bead of the right one.
Colors and trim matter to owners. I like to match eave and gable trim to the panel color for a long, continuous look, and choose a contrasting color for gutters if the architecture benefits from definition. Downspouts and splash blocks should be in the plan. On commercial metal roofing, scuppers and conductor heads may be required, and it pays to mock these with the owner to get heights, shapes, and overflow paths right.
Inspection, walkthrough, and documentation
When the last cap is on, we do a water path test. I do not soak the whole roof with a hose, but I trace critical areas like valleys, skylight curbs, and sidewalls, watching for micro-channels where water might creep. Inside the attic, a quick check for daylight at penetrations or around ridge vents catches small gaps before they are a problem.
Then comes the magnet sweep. The best crews run magnets twice, once at midday and again when the light rakes across the driveway and reveals what the first pass missed. We wipe down visible panels with soft cloths to remove footprints and drilling swarf that will rust. I photograph key details for the client file: valley layout, chimney cricket, ridge vent assembly, and serial numbers for any skylights or accessories. That package helps with warranty registration and later service calls.
What changes on commercial projects
Commercial roofs bring scale and different pressures. Long panel runs demand expansion planning, often with fixed points at midspan and sliding clips toward both ridge and eave. More penetrations for HVAC, exhaust, and parapets require curbs and walk pads to protect the roof during maintenance. On low-slope retrofits, I often specify mechanically seamed panels with sealant in the seams and a continuous ice-and-water shield underneath. The installation speed drops, but the system holds up to pooling water driven by wind.
Safety expands as well. On a warehouse we re-roofed, we scheduled daily tie-off checks and placed controlled access zones below active areas so forklifts did not pass under roof edges. These steps slow productivity slightly but protect teams and avoid OSHA headaches. Local metal roofing services with a track record in your jurisdiction already know these routines and keep work moving.
Working with a metal roofing company: what to ask
Homeowners and facility managers do not need to be roof experts, but a few questions reveal a lot about a contractor’s competence.
- Which panel systems do you install most often, and why do they suit my roof? How will you handle ventilation, especially soffit intake and ridge exhaust, and what changes might be needed in my attic? Can you show details for my roof’s problem areas, such as the chimney, valley junctions, or low-slope sections? What is your plan for snow retention or gutter compatibility, and how will you protect landscaping and protect against fastener debris? What maintenance should I expect over 5, 10, and 20 years, and how do you handle metal roofing repair or storm damage?
A seasoned metal roofing company answers these without hedging, brings manufacturer literature to back up claims, and offers photos of similar jobs. They also put names to crew leaders and explain their schedule, not just a vague timeframe. If a proposal glosses over flashings or ventilation, you are likely looking at a shingle mindset applied to metal, which leads to callbacks.
Cost, timelines, and what drives both
Owners often expect metal to cost two to three times shingles. That range holds in many markets but shifts with panel choice, gauge, geometry, and access. Exposed fastener systems can land close to architectural shingles, while premium standing seam in 24 gauge with custom flashings, snow rails, and high-temp underlayment prices higher. Complex roofs with dormers and valleys cost more per square than big rectangles with wide eaves.
Timelines vary. A straightforward 2,500 square foot ranch with a single ridge and two valleys might take a three-person crew four to six days including tear-off, underlayment, panels, and trim. Add two skylights and a chimney cricket, and you add a day. Weather always plays a role. Metal can go on in light rain if the underlayment is down and safe footing is possible, but tear-off in bad weather is a poor gamble. Good metal roofing contractors will stage the job to keep your house dry at every step.
Common mistakes and how to avoid them
Experience has taught our crews to watch for certain pitfalls.
- Starving expansion. Locking panels at both ridge and eave with fixed clips or screws in slotted holes can buckle pans as temperatures swing. Plan a fixed point and let the rest move. Underestimating water at transitions. A pretty sidewall flashing without a kick-out at the bottom can send water behind the siding. Always include a kick-out where a roof meets a vertical wall that drains to a gutter. Ignoring small dips. A quarter inch deck dip telegraphs through a flat pan and looks like oil canning. Shimming with roofing felt or tapered strips before panel installation evens the plane. Perforating the wrong spot. Fastening into panel flats in systems designed for rib fastening invites leaks. Follow the panel’s fastening pattern exactly. Overtrusting sealant. Sealant ages faster than metal. If a leak depends on a single bead of sealant, redesign the detail.
These issues are easier to prevent than to repair. When you call for metal roofing repair years later, the best fixes mirror the best original practices: mechanical laps, correct flashings, and updated accessories where technology has improved.
When replacement beats repair
Metal can last 40 to 70 years depending on environment and maintenance. But not every problem warrants a new system. A well-placed patch on a punctured panel, a boot replacement at a cracked vent, or a re-secured ridge cap may extend life by a decade. Metal roof repair makes sense when the coating is sound and corrosion is superficial. Metal roof replacement becomes the smart choice when fastener back-out is widespread on exposed systems, when panels https://rowanltwc937.bearsfanteamshop.com/new-metal-roof-installation-step-by-step-overview show red rust through the coating, or when a roof was installed without proper ventilation and exhibits systemic condensation damage. A local metal roofing services provider who inspects rather than guesses can quantify the damage and outline both paths with costs.
Warranty, maintenance, and the long view
There are two warranties to understand: the paint finish warranty and the workmanship warranty. A PVDF paint warranty might promise 30 to 40 years against excessive fade or chalk, under specific conditions and colors. Workmanship warranties from a contractor typically run 2 to 10 years. Manufacturer weathertight warranties exist on certain commercial systems when the installer is certified and the details pass inspection. Read these documents carefully. They spell out maintenance expectations, such as cleaning debris from valleys and avoiding roof traffic without proper walk pads.
Maintenance is not heavy, but it is real. Once a year, walk the ground after a storm and scan the roof for disturbed caps or debris piles. Clean gutters and valley leaves. After trades access the roof for satellite installs, HVAC work, or chimney service, check their path. I have seen more leaks from well-meaning technicians with lag screws and silicone than from any weather event. Establish a rule: if someone must anchor anything to the roof, they call the roofing contractor first.
Final thoughts from the field
A new metal roof installation is a craft, not a kit. The success of the system comes from a chain of correct decisions, each one small enough to overlook. Choose a profile and metal that suit the building. Prepare the deck and ventilation so the roof can breathe. Lay out panels with patience, respect expansion, and let flashings do the water work. And partner with a metal roofing company that answers clearly and builds what it sells.
When done well, metal pays you back in a hundred quiet ways. Summer heat radiates less into the attic. Heavy rain runs cleanly without the drumbeat people fear. Winter snow slides when you want it to, and stays when you do not, thanks to rails set with intention. Twenty years from now, a light wash and a once-over of fasteners are your repair list. That, more than any brochure, is the promise of a proper metal roof.
Metal Roofing – Frequently Asked Questions
What is the biggest problem with metal roofs?
The most common problems with metal roofs include potential denting from hail or heavy impact, noise during rain without proper insulation, and higher upfront costs compared to asphalt shingles. However, when properly installed, metal roofs are highly durable and resistant to many common roofing issues.
Is it cheaper to do a metal roof or shingles?
Asphalt shingles are usually cheaper upfront, while metal roofs cost more to install. However, metal roofing lasts much longer (40–70 years) and requires less maintenance, making it more cost-effective in the long run compared to shingles, which typically last 15–25 years.
How much does a 2000 sq ft metal roof cost?
The cost of a 2000 sq ft metal roof can range from $10,000 to $34,000 depending on the type of metal (steel, aluminum, copper), the style (standing seam, corrugated), labor, and local pricing. On average, homeowners spend about $15,000–$25,000 for a 2000 sq ft metal roof installation.
How much is 1000 sq ft of metal roofing?
A 1000 sq ft metal roof typically costs between $5,000 and $17,000 installed, depending on materials and labor. Basic corrugated steel panels are more affordable, while standing seam and specialty metals like copper or zinc can significantly increase the price.
Do metal roofs leak more than shingles?
When installed correctly, metal roofs are less likely to leak than shingles. Their large panels and fewer seams create a stronger barrier against water. Most leaks in metal roofing occur due to poor installation, incorrect fasteners, or lack of maintenance around penetrations like chimneys and skylights.
How many years will a metal roof last?
A properly installed and maintained metal roof can last 40–70 years, and premium metals like copper or zinc can last over 100 years. This far outperforms asphalt shingles, which typically need replacement every 15–25 years.
Does a metal roof lower your insurance?
Yes, many insurance companies offer discounts for metal roofs because they are more resistant to fire, wind, and hail damage. The amount of savings depends on the insurer and location, but discounts of 5%–20% are common for homes with metal roofing.
Can you put metal roofing directly on shingles?
In many cases, yes — metal roofing can be installed directly over asphalt shingles if local codes allow. This saves on tear-off costs and reduces waste. However, it requires a solid decking and underlayment to prevent moisture issues and to ensure proper installation.
What color metal roof is best?
The best color depends on climate, style, and energy efficiency needs. Light colors like white, beige, or light gray reflect sunlight and reduce cooling costs, making them ideal for hot climates. Dark colors like black, dark gray, or brown enhance curb appeal but may absorb more heat. Ultimately, the best choice balances aesthetics with performance for your region.