Metal roof over shingles roof.

[breadtrk]

Furring strips nailed through shingles, into rafters, screw on metal. KISS.

 

[R134a]

Some thoughts... Lifetime warranty =no such thing. "lifetime" in legal terms typically means 20 years. My warranty on my metal rib roof was 40 years. Completely worthless. All the screws unscrewed themselves as well as the paint was oxidized and beginning to rust after 8 years. Roofer says its the metal maker's fault. They say its the roofer's fault. There's the "warranty". Another roofer convinces me to go with shingles. That was $21k and lasted a whopping 2 years as we had a hurricane. Pulled off the cap shingles and power washed all the granules off so the shingles are ruined. Now I have a standing seam roof as the screws are underneath the metal. A pile of money spent and more promises. We will see what happens.

 

[Oaktree]

Furring strips nailed through shingles, into rafters, screw on metal. KISS.

That's what I did when I put a metal roof on my garage. 12 years later, still looks good, no leaks.

Some thoughts... Lifetime warranty =no such thing. "lifetime" in legal terms typically means 20 years. My warranty on my metal rib roof was 40 years. Completely worthless. All the screws unscrewed themselves as well as the paint was oxidized and beginning to rust after 8 years. Roofer says its the metal maker's fault. They say its the roofer's fault. There's the "warranty". Another roofer convinces me to go with shingles. That was $21k and lasted a whopping 2 years as we had a hurricane. Pulled off the cap shingles and power washed all the granules off so the shingles are ruined. Now I have a standing seam roof as the screws are underneath the metal. A pile of money spent and more promises. We will see what happens.

As with anything, quality materials and proper installation are the key to long life. All bets are off with a hurricane.

You don't say where you live, but if you had a hurricane rip an almost new shingle roof off I'd guess it's the deep south or gulf coast. How do asphalt shingles stand up under that kind of heat? Wouldn't think they'd be the best choice. Here in New England it's not uncommon to get 30+ years out of a properly installed asphalt roof.

 

[R134a]

Code here is min 5 nails/shingle. It held better than I thought. There was a handful that flipped up but were still on. Didn't matter if they were fixed because there would always be another on found after the roofer leaves and... the water wind combo washed all the granules off so the shingles are ruined anyway. It was white to reflect heat as I live in NW FL. The new roof is silver to reflect max heat. The sun does a number on everything here. SS roof is the best option but very expensive. Shingle in the Northeast is more practical as it is underneath snow in the winter. Agree install quality is just or even more so important than the materials.

 

[Kyle_in_Tex]

Here's probably the best reading I've found on this. I believe half the war down the road is keeping bees and pests out of the air gaps.

Cool Roof Design for Hot Texas Climate | Houston Cool Metal Roofs