How the two differ in kind
Asphalt shingles dominate for reasons that are all about the install: any roofing crew knows them, they forgive imperfect substrates and complex roof shapes, every hip and valley is a solved detail, and a repair is a bundle and an afternoon. Their cost is time: an organic-mat shingle roof is a consumable with a service life, sensitive to heat cycling and to the granule loss that starts the day it is laid.
A metal roof is a different investment shape. The material runs eave to ridge in single panels, so there are radically fewer joints — and joints are where roofs fail. Done properly it sheds snow, shrugs off UV, and lasts multiples of a shingle roof. The 'done properly' is the catch: fewer joints means each one matters more, expansion must be designed for (panels move with temperature and the fastening system must let them), and the crew that details a valley in standing seam well is scarcer than the shingle crew.
Roof geometry votes too. A simple long gable is metal's home ground — full-length panels, minimal cutting. A cut-up roof full of dormers and hips erodes metal's advantage cut by cut, while shingles barely notice complexity.
The factors that actually differ
Show
| Metal panels | Asphalt shingles | |
|---|---|---|
| Joints and failure points | Panels run full length; side laps engineered — few joints, each one critical. | Thousands of overlaps that are collectively forgiving and individually trivial. |
| Roof shape sensitivity | Loves simple planes; every hip, dormer and penetration is a fabricated detail. | Indifferent to complexity; cutting shingles around anything is routine. |
| Thermal movement | Real and designed-for: clip systems exist because panels grow and shrink daily. | Absorbed invisibly by thousands of small units. |
| Weather character | Sheds snow in slabs (plan for guards over doors); loud rain is a myth over a deck, real over open framing. | Holds snow; loses granules to hail; heat ages it measurably. |
| Repair | A damaged panel is a panel swap — order the profile, match the colour lot. | A bundle from the yard and an hour; matching decade-old colour is the only trick. |
| Crew availability | Specialist detailing; the quote spread between crews is wide. | Universal; competitive quoting keeps labour honest. |
| Thermal movement | Expands and contracts noticeably along its length, which is why panels are fixed with clips that allow movement rather than being pinned. A pinned long panel distorts or tears at its fixings. | Individually small units, each free to move relative to its neighbours. Thermal movement is absorbed by the assembly and is a non-issue. |
| Foot traffic afterwards | Dents, and denting is permanent. Anyone servicing an aerial, a flue or a solar array needs to know where the purlins are. | Tolerates careful traffic on a warm day; brittle and easily broken when cold. |
| Noise in rain | Depends entirely on what is under it. Fixed to battens over a ventilated void it is loud; over a deck with underlay and insulation it is not remarkable — the reputation comes from the first arrangement. | Quiet, because the covering is bedded on a continuous deck. |
| Snow behaviour | Sheds in slabs, which is a hazard below eaves over a door or a path and the reason snow guards exist. It also means less accumulated load. | Holds snow, which loads the structure and, in the wrong conditions, feeds ice dams at the eaves. |
Which one, and when
Choose metal panels when…
- You intend to own this roof's whole life, and the maths of one roof versus two favours it.
- Simple roof planes that let panels run full length.
- Snow country, where shedding beats holding.
Choose asphalt shingles when…
- A complex, cut-up roof where metal's detailing cost compounds.
- The budget decides, or the ownership horizon is short.
- You want any competent local crew able to repair it in an afternoon, forever.
Now run your own numbers
This page holds no prices on purpose — a national average is wrong for almost every real project. Quantify both options with your dimensions and your local quotes.
Frequently asked questions
- Can metal go over old shingles?
- Often yes, over battens that create a vent gap and a fastening plane — it saves the strip-off cost and landfill. The conditions: the structure must take the (modest) extra weight, local code must allow the layer count, and the old roof must be flat enough not to telegraph. A spongy deck disqualifies the shortcut; metal over rot is rot with a lid.
- Is a metal roof loud in rain?
- Over a solid deck with underlayment — which is how houses are roofed — the difference from shingles is small; the drum effect people remember comes from barns with panels on open purlins. Over a bedroom it is a non-issue; over a bare carport it is real.
- Which is better for solar panels later?
- Standing seam, decisively: clamp-on mounts grip the seams with zero roof penetrations. On shingles every mount is a flashed hole, and the panels will outlive the shingles beneath them — which means lifting the array to reroof. If solar is in the plan, that alone can settle this comparison.
- Is a metal roof really noisy in rain?
- Only in one of the two ways it is commonly built, and the difference is what is underneath rather than the metal. A sheet fixed to battens over an open ventilated void has a large drum surface with air behind it, and that is loud. The same sheet laid over a solid deck with underlay and insulation beneath it is not remarkable, because the deck damps the panel and the insulation absorbs what gets through. Most modern residential metal roofing is the second arrangement, and most of the reputation comes from the first — agricultural and outbuilding roofs, where nobody was insulating anything. If noise matters, the question to ask is about the build-up under the metal, not about the metal.
- Will a metal roof make the house hotter?
- The opposite, generally, and by more than people expect. A reflective metal surface re-emits a large share of the solar energy that lands on it rather than conducting it into the roof space, so attic temperatures under metal run substantially cooler than under dark asphalt on a sunny day. The effect is largest with a light or reflective coating and smallest with a dark one, and it matters most in a cooling-dominated climate. Where the roof space is insulated at ceiling level and ventilated, the benefit to the rooms below is modest but real; where the insulation is at the roof line, it is larger.
- Can I put metal over existing shingles?
- Often, and it is one of the reasons metal is chosen for a re-roof — but three questions come first. Weight: adding a covering to an existing one adds load, and metal is light enough that this is rarely the constraint. Moisture: anything trapped between the layers cannot dry, so a wet or deteriorated underlay beneath is a problem being covered rather than solved. And flatness: metal panels telegraph what is under them, so an uneven shingle surface shows through, which is why a batten or furring system over the old covering is common. Local codes also limit the number of coverings permitted before a full strip, and that limit applies regardless of what the new one is.
- What actually fails on each?
- On metal, the fixings and the details rather than the sheet. Exposed fasteners with washers are the weak point of the cheaper systems — the washers perish and the holes weep, typically at a age well short of the panel's own life — which is why standing seam with concealed clips is the specification for a long life. Corrosion at cut edges and at contact with incompatible metals is the other one. On shingles, the material itself ages: the binder oxidises, the granules that protect it wash off, and the shingle becomes brittle and curls. Both are then defeated by the same thing at the same place, which is the detailing at valleys, penetrations and abutments, where the covering is not what keeps water out.