We're looking at a house that happens to have a metal roof. What is the average life of a metal roof compared to a typical shingle roof? I like the way it looks and it seems like it'd be more durable. Are they prone to leaking at joints or where screws go in or is that not an issue. Are there any Cons we need to be aware of?

My grandpa has one and the only con I've seen is I can forget using my cell phone inside his house for anything. I can walk outside and it will instantly start working again so now I don't even take it inside with me anymore.

Make sure it’s not a metal roof on top of shingles.

Wouldn't have thought they'd even do that. Why, specifically, is that bad?

I like our metal roof. It's on top of shingles. The phone reception is an issue.

It cuts down on the expense of having to take all the old shingles off. As far as I'm aware, every metal roof I've known has just went right over the existing shingles.

I don't have a metal roof but I see them all over that have faded, looks bad. I do like the way a standing seam metal roof looks, I believe that's what its called.

you will probably have a screw or two that leaks or is missing. not hard to fix, but they can be hard to find. also if you have a steep pitch it is very slippery to walk on. condensation can also be an issue in some cases.

It’ll make your attic hotter than hell. And depending on which direction the furring is run; will cause some serious leaks once the rubber gaskets on the screws wear out.

So they need slats inbetween the shingles and tin. That's way we've always done it.

If your “slats” are run horizontal to the joints on the metal panels, as soon as one of those rubber gasket screws fail, the water piles up on your slats.

My roof is metal over shingles and no problems with that aspect. I had it installed after Ivan threw a tree limb thru the roof, punching a 9"-10" hole in it.
We always wanted a Metal Roof anyways so it worked out, we just had crappy installer and since I lived in Panama City at the time, we werent there for inspections but heck, I didn't know squat about roofing to begin with so I wouldn't have known what to look for.
My only complaint is the screws backing out. Several times since the Metal roof was installed in 2005, I've had to replace the screws with larger diameter ones.
Finally having had enough of the leaks this past spring i researched and found the problem and solutions.
First make sure your screws has the 1 piece bonnet that is molded with the screw head and not the "washer" type.
Be certain that screw length will completely penetrate thru the Purling and into the decking.
Make sure the screws are Woodgrip for wood and Tek for metal. I used the WoodZak type screws, they are a bit more expensive but well worth it.
I would definitely have inspector climb onto the roof and look at it or if you're not using an Inspector, then you get on the roof and look at the screws and washers. Look for cracked rubber washers or over expanded washers. Look for screws that are backed out or screws that have obviously been replaced and/or have sealant smeared on the screw heads. I used sealant like this in the effort to solve the screws backing out and to stop leaks.
As for fading, mine has faded somewhat in these 13 years but not bad at all and still looks good.
Good Luck with the House hunting!

I got one phone isn't a problem but I've seen screws pop out on sum so keep check on it

You do not want a metal roof directly on shingles. The expansion and contraction will wear the finish off the bottom of the sheet leading to it rusting. I was also told it will void the warranty with almost every metal supplier.

A metal roof for me was $350 cheaper than going back with standard 3 tab shingles.
How many 50 yr old barns ya see with their original shingle roof vs tin roofs ?

I put a metal roof on my house in March. I love it. it did affect my cell service a little but still have good signal. I think they look better than a shingle roof too. I went with the galvilume rather than a colored metal. love the sound when it rains.

Rain water comes down the metal roof a LOT faster than a shingle roof.
If you have screws back out, get a tube of Lexel, screw them out and put a good dab in the hole before re-applying the screw.
If you aren't sure which one is leaking, take out all of the screws in the area and Lexel them.

Who puts the metal directly on the shingles anyhow lol

Always liked the green, but it looks like crap when it fades, that's why i went with Galvalume

We went with galvalume on our cabin. I designed it basically like this:

5/8" plywood T-111 decking over the rafters
Vapor barrier over decking
Double 2x4 blocking on 24" centers over that perpendicular to the rafters
R-15 insulation in between the blocking
1/2" decking over all of that
Waterproof barrier over that
Metal roofing screwed through the decking and into the blocking.

It's sort of a sandwich type construction similar to an Alaska roof. I did it this way because my rafters and the pretty side of the T-11 are exposed to the bedrooms below.

I don't know of any downside to a metal roof as of yet. We are sleeping in the cabin now in one of the upper bedrooms and I haven't noticed any more noise with that set-up when it rains than with our traditional shingle roof at home.

One thing about a metal roof is that you can collect rain water off of it for drinking, watering plants, etc... Whereas a shingle roof you aren't supposed to because of the chemicals it leaches. Until we got city water up there we had planned to collect rain water from the roof into a large cistern for our main water source. All houses in the British Virgin Islands are set up this way with the whole basement being giant under ground cisterns.

When we build the house at the beach we will go with a galvalume roof also. I don't see how a galvalume roof would be any hotter than a black asphalt roof. If anything it would be cooler. Lighter colors reflect heat and darker colors absorb it.