For most houses on a subdivision street around Knoxville, architectural shingles are the better buy. For a steep cabin, an old farmhouse, or a home you plan to stay in for a very long time, metal starts to earn its price. That's our opinion, and the rest of this post is how we get there, using the numbers we could actually find.
How much more does metal cost?
The Metal Roofing Alliance, the trade group for the metal roofing industry, says a metal roof costs roughly two to three times what an asphalt shingle roof costs (Metal Roofing Alliance). Around Knoxville, most asphalt shingle replacements on homes run $15,000 to $30,000, so you can do the rough math on your own house.
Where your price lands inside that range depends on the kind of metal, the panel thickness, how steep and cut up the roof is, and how much decking needs fixing underneath. A simple ranch with two big slopes and a cabin with dormers and a wraparound porch can be priced very differently even at the same square footage.
Does metal pay for itself over the life of the roof?
Be careful with the numbers here. The same trade group says to count on a metal roof lasting 30 to 50+ years, and puts the average asphalt roof at 12 to 20 years. Keep in mind who's talking. A metal trade group has every reason to put shingles at the short end, and a shingle maker would tell the story differently.
Still, you can use their own figures to find the break-even point. If metal costs twice as much, it has to last twice as long to cost the same per year. Here's how that works out against the 12 to 20 years they give for asphalt:
| Metal's price compared to shingles | How long metal has to last to break even |
|---|---|
| Two times as much | 24 to 40 years |
| Three times as much | 36 to 60 years |
Against a 30 to 50+ year life, metal at twice the price comes out ahead per year. At three times the price, it's close, and it only wins if you stay long enough to collect.
That's the real question for most people. If you sell before the shingles would have worn out, you paid the higher price and the next owner gets most of the life. The trade group also says metal can typically save 10 to 40 percent on energy costs. That range is wide enough that we wouldn't count on it when you're doing your own math.
Is a metal roof loud in the rain?
On a house, usually not. The Metal Roofing Alliance says there's little difference between metal and other materials in the noise from rain or hail. That matches how a house roof is built. The panels sit on solid decking and underlayment, with an attic and insulation between the roof and your bedroom, and each of those layers soaks up sound.
The loud metal roofs people remember are on barns and porches. There, the panels are screwed straight to open framing, and nothing sits between the metal and your ears.
What happens when hail hits metal?
It can dent. A big enough stone leaves dimples in the panels, and thinner, softer metal dents more easily than heavier panels. A dent usually doesn't leak. It's a looks problem.
Shingles fail differently in hail. The stone knocks granules off and can crack the shingle underneath, and that shortens its life even when the roof looks fine from the ground.
Before you buy either one, ask your insurance agent two questions: does your policy cover dents that don't cause a leak, and do they give any discount for an impact-rated roof. The answers vary by company, and they're worth knowing before you sign.
Standing seam or exposed fastener?
Those are the two kinds of metal roof you'll see on houses here.
| Standing seam | Exposed-fastener panels | |
|---|---|---|
| How it's held down | Hidden clips under raised seams, no screws through the face | Screws through the face of the panel, with rubber washers |
| Up-front price | Higher | Lower |
| Upkeep | Little | Screws and washers need checking over the years |
| Where it fits | Homes and cabins people plan to keep | Barns, shops, outbuildings, budget cabins |
The washers on an exposed-fastener roof are the weak spot. The rubber ages in the sun, and a screw that backs out turns into a small leak. If you go that way on a house, plan on someone checking the screws every few years.
Which houses suit metal
Some houses suit metal better than others.
- Steep cabin roofs in Sevier County, where metal sheds rain and leaves fast and nobody wants to reroof a hard-to-reach slope twice. Our Sevierville page covers roofs in that part of the county.
- Farmhouses and older country homes where metal was the original look.
- Barns, shops and outbuildings, where exposed-fastener panels make sense on price.
On an HOA street, read your covenants before you fall for a metal roof. Some neighborhoods limit roof materials or colors, and the architectural committee has to sign off before work starts. Plenty of subdivision houses also just look right in shingles, and resale buyers on those streets expect them.
Can metal go right over the old shingles?
Sometimes it's allowed, but there are good reasons to tear off first, and they're laid out in metal over shingles: why tear-off is usually better.
How to decide
The fair way is to see both on paper for your own roof: the same measurements, the same decking allowance, two prices. Our metal roofing page covers what goes into a metal price, and the roof replacement page does the same for shingles. If you want to see panel styles and colors first, look at the metal products on our products page.
Questions
Can I walk on a metal roof?
Try not to. Panels can dent under a boot, and painted metal is slick when it's wet or dusty. Leave it to someone with the right shoes and a harness.
Does a metal roof change anything about the gutters?
It can. Metal sheds water and snow faster than shingles, so some houses need snow guards over doorways and walkways, and the gutters have to be sized and hung to take the faster runoff.
