Metal Roof

[WRM]

I know a person on 30A with a spray foam rafter house. Was great r-value, but just like above post said, a leak developed, probably 10 years back, foam hid leak, trapped it, and let it spread over a huge area. Now rafters, sheathing, foam, and roof need to be replaced. Oh requires mold remediation now. Big $! Open cell foam and moisture are not a good combo. Fortunately he has cinder block for exterior walls but moisture worked it's way down the interior of 3 floors. Good thing his pockets are deep and it's his "little" 5000 sq ft summer, beach home.
I understand that he wants to insulate airspace between battens. Waste of time, money and a bad idea.

Thur ya go, Chingy.

And closed cell foam and moisture don't make a good combo either. Trapped moisture is never a good thing. See my above comment on EFIS.

I got a good mold remediator.

 

[Rebuilt]

My only thing with a metal roof is how long do all those washers on the screws last? Seems like they would dry out and shrink and become leaks

Did metal roofing on my Dads old house and our old workshop after Ivan, never had a leek. We actually removed some roof panels for from the shop before we sold the property and the screws were still good and the washers hadn’t degraded all that much. We put standing seam on our new place and it most of the hardware is hidden

 

[WRM]

My only thing with a metal roof is how long do all those washers on the screws last? Seems like they would dry out and shrink and become leaks

Ultimately, they can. I think the roofer I have dealt with suggested 7 years replacement. If you don't and get a leak, I'm quite sure a claim
under wty would be denied. Another reason why I'd take old roofing off, put on peel n stick and then the metal. Likelihood you are going to get a leak from degraded screw which then also gets thru peel n stick is fairly low. Still, screws are supposed to be replaced on a schedule. This may well not apply to standing seam. I could not afford that.

 

[Anyting5dolla]

I would leave the air gap for expansion and contraction. A well ventilated roof will last much longer than than one that is not!

Yes ventilated roofs last longer if you have vented ridge and soffit. But gap there shouldn’t be a gap in the roof if there isn’t ventilation cuts at the ridge for it to be vented otherwise wind load will snatch the panels or trim right off.

 

[Anyting5dolla]

Did metal roofing on my Dads old house and our old workshop after Ivan, never had a leek. We actually removed some roof panels for from the shop before we sold the property and the screws were still good and the washers hadn’t degraded all that much. We put standing seam on our new place and it most of the hardware is hidde

Ultimately, they can. I think the roofer I have dealt with suggested 7 years replacement. If you don't and get a leak, I'm quite sure a claim
under wty would be denied. Another reason why I'd take old roofing off, put on peel n stick and then the metal. Likelihood you are going to get a leak from degraded screw which then also gets thru peel n stick is fairly low. Still, screws are supposed to be replaced on a schedule. This may well not apply to standing seam. I could not afford that.

Standing seems hardware shouldn’t be seen at all other than pop rivets in the trim.

 

[WRM]

Standing seems hardware shouldn’t be seen at all other than pop rivets in the trim.

What I assumed, but I'm not familiar with SS.

 

[WRM]

Yes ventilated roofs last longer if you have vented ridge and soffit. But gap there shouldn’t be a gap in the roof if there isn’t ventilation cuts at the ridge for it to be vented otherwise wind load will snatch the panels or trim right off.

I won't post further on ventilation as I covered it in #57--it has been disproven as needed in the South. You're going to get it, however, thanks to Nat Code.

 

[Anyting5dolla]

What I assumed, but I'm not familiar with SS.

There’s a lot of “profiles” of standing seem. And a lot of different techniques people do. I do mine where there are no visible screws and use rivets on my trim details.

 

[Anyting5dolla]

I won't post further on ventilation as I covered it in #57--it has been disproven as needed in the South. You're going to get it, however, thanks to Nat Code.

Yeah might not be required and I’ve done roofs that arnt required for it to have ventilation. But I’ve seen roofs sense Ivan without and some with. (Shingled homes) The ones without were changed out around the 10-13th year because the heat we get here bakes the shingles and if no ventilation is in place you have a attic that’s always hot cooking your shingles from the inside out. Then the ones with are still around today people tear them off everyday and also run a baton system with tuff rib panels or a standing seem panel profile. Metal roofs are different when it comes to ventilation it’s not required but it’s recommended depending on the project itself.

 

[Rebuilt]

Standing seems hardware shouldn’t be seen at all other than pop rivets in the trim.

Exactly

 

[WRM]

Yeah might not be required and I’ve done roofs that arnt required for it to have ventilation. But I’ve seen roofs sense Ivan without and some with. (Shingled homes) The ones without were changed out around the 10-13th year because the heat we get here bakes the shingles and if no ventilation is in place you have a attic that’s always hot cooking your shingles from the inside out. Then the ones with are still around today people tear them off everyday and also run a baton system with tuff rib panels or a standing seem panel profile. Metal roofs are different when it comes to ventilation it’s not required but it’s recommended depending on the project itself.

On the shingled roof, yes they get "baked", but really has little to nothing to do with attic ventilation. The studies I have read clearly show only a minimal (virtually meaningless) decrease in heat gain/attic temp for "ventilated" roofs. Again, ventilation is needed in colder climates to prevent moisture emanating from the climate controlled envelope from freezing up in the attic insulation. We don't have that issue here--we just have ample hot air with no real chance of water vapor condensing and then freezing in the attic.

Shingle decomposition has a lot more to do with a (typically) black shingle in the direct and intense FL sun. The shingled roof, in direct contact with the sheathing, is a perfect heat sink to move heat into the attic. Ventilating the attic does not "get rid of" this heat. The building materials themselves (ie rafters) are heating up.

An air gapped metal roof is the way to go if you really want to decrease your attic heat gain and have a greater level of wind damage protection.

Sure wish I could swallow the bill for a SS on my house.

 

[Anyting5dolla]

On the shingled roof, yes they get "baked", but really has little to nothing to do with attic ventilation. The studies I have read clearly show only a minimal (virtually meaningless) decrease in heat gain/attic temp for "ventilated" roofs. Again, ventilation is needed in colder climates to prevent moisture emanating from the climate controlled envelope from freezing up in the attic insulation. We don't have that issue here--we just have ample hot air with no real chance of water vapor condensing and then freezing in the attic.

Shingle decomposition has a lot more to do with a (typically) black shingle in the direct and intense FL sun. The shingled roof, in direct contact with the sheathing, is a perfect heat sink to move heat into the attic. Ventilating the attic does not "get rid of" this heat. The building materials themselves (ie rafters) are heating up.

An air gapped metal roof is the way to go if you really want to decrease your attic heat gain and have a greater level of wind damage protection.

Sure wish I could swallow the bill for a SS on my house.

Yes and shingles have ventilation at the ridge cap to allow the air inside the attic to escape. Plus if your homes were built with plywood sheathing then both shingles and metal panels have underlayment. Most homes are built with trusses and plywood sheathing. There would be no actual reason to baton a home that is brand new with peel and stick on it for ventilation for your panels. You can read the studies all you want I put roofs on everyday I’ve been at this for awhile and I’ve put on nearly every roofing system out there. Air gapping your roof will give hard wind from say a hurricane easier access to blow the panels off your house. You can dm me your sources because I would love to see the detail on this blueprint and how they think they’ll keep 150+mph winds from snatching these panels off.

 

[WRM]

Yes and shingles have ventilation at the ridge cap to allow the air inside the attic to escape. Plus if your homes were built with plywood sheathing then both shingles and metal panels have underlayment. Most homes are built with trusses and plywood sheathing. There would be no actual reason to baton a home that is brand new with peel and stick on it for ventilation for your panels. You can read the studies all you want I put roofs on everyday I’ve been at this for awhile and I’ve put on nearly every roofing system out there. Air gapping your roof will give hard wind from say a hurricane easier access to blow the panels off your house. You can dm me your sources because I would love to see the detail on this blueprint and how they think they’ll keep 150+mph winds from snatching these panels off.

I never said I read studies on wind uplift. Sorry if I implied that somehow. Wind loading is handled via an engineering certification for a roof system. I have no need to read studies about what engineers say on wind loading. What they have done is certify that the system (properly installed) "can" survive a certain amount of wind loading. Let a storm come in that "sits" and blows that certified wind for hours on end and all bets are off. Take a look at the destruction scales for different levels of storm. At some point, you can not economically try to accommodate that challenge. End of the day--mother nature wins if she wants to. I am not focusing on and have not focused on wind loading.

The vast, vast majority of homes I am aware of built in the last 40ish years or so have OSB decking, not "plywood". But I'd sure agree that trusses normally are used in res construction. I've built a few, including what I thought was my last house in the late 90s (that wife decided otherwise). Builder just laughed when I asked what it would cost to go from OSB to sheet plywood. I currently live in a house my grandparents built in '52. It has tongue and groove plank decking. IF I can ever afford to get a metal roof on it, the system should outlast me by a good long while.

A batten installation has nothing whatsoever to do with giving "ventilation to your panels". The air gap serves to keep the metal from contacting the decking, and that reduces the heat transfer into the attic via materials in contact with each other. That is physics--I certainly didn't invent it. Personally, I'd much rather have that benefit every day of our long cooling season (particularly at FPL rates) than worry about a potential storm I may not be able to prevent damage from no matter what I do. Again, the system (including battens) has been certified by an engineer to sustain X wind load. Good enough for me.

Allowing "air" inside an attic to "escape" does next to nothing to assist in cooling an attic. A reason is the building materials themselves are gaining heat (which they discharge overnight so the cycle can start over the next day). A major reason the material is gaining heat in your attic is transference through roofing material that is IN DIRECT CONTACT with the roof decking, which is in direct contact with the trusses and so on and so on. Black shingles are one of the worst. Black metal roofing (not air gapped) would be about as bad. Air gap it and you cut way down on heat transfer into your attic. If mere ventilation (ie ridge and soffit vents) really did anything positive (in OUR climate), you'd see actual attic temps getting closer to an equilibrium with outside air temps LIKE YOU SEE WITH AIR GAPPED METAL ROOFS!

Again, it's physics (and not real complicated physics). Believe it or don't--couldn't care less.

 

[Anyting5dolla]

I never said I read studies on wind uplift. Sorry if I implied that somehow. Wind loading is handled via an engineering certification for a roof system. I have no need to read studies about what engineers say on wind loading. What they have done is certify that the system (properly installed) "can" survive a certain amount of wind loading. Let a storm come in that "sits" and blows that certified wind for hours on end and all bets are off. Take a look at the destruction scales for different levels of storm. At some point, you can not economically try to accommodate that challenge. End of the day--mother nature wins if she wants to. I am not focusing on and have not focused on wind loading.

The vast, vast majority of homes I am aware of built in the last 40ish years or so have OSB decking, not "plywood". But I'd sure agree that trusses normally are used in res construction. I've built a few, including what I thought was my last house in the late 90s (that wife decided otherwise). Builder just laughed when I asked what it would cost to go from OSB to sheet plywood. I currently live in a house my grandparents built in '52. It has tongue and groove plank decking. IF I can ever afford to get a metal roof on it, the system should outlast me by a good long while.

A batten installation has nothing whatsoever to do with giving "ventilation to your panels". The air gap serves to keep the metal from contacting the decking, and that reduces the heat transfer into the attic via materials in contact with each other. That is physics--I certainly didn't invent it. Personally, I'd much rather have that benefit every day of our long cooling season (particularly at FPL rates) than worry about a potential storm I may not be able to prevent damage from no matter what I do. Again, the system (including battens) has been certified by an engineer to sustain X wind load. Good enough for me.

Allowing "air" inside an attic to "escape" does next to nothing to assist in cooling an attic. A reason is the building materials themselves are gaining heat (which they discharge overnight so the cycle can start over the next day). A major reason the material is gaining heat in your attic is transference through roofing material that is IN DIRECT CONTACT with the roof decking, which is in direct contact with the trusses and so on and so on. Black shingles are one of the worst. Black metal roofing (not air gapped) would be about as bad. Air gap it and you cut way down on heat transfer into your attic. If mere ventilation (ie ridge and soffit vents) really did anything positive (in OUR climate), you'd see actual attic temps getting closer to an equilibrium with outside air temps LIKE YOU SEE WITH AIR GAPPED METAL ROOFS!

Again, it's physics (and not real complicated physics). Believe it or don't--couldn't care less.

Lol dude I really good not care less either way you’ll be calling a roofer to install it on your house. Hope you pick a good contractor because there’s a lot of not so decent ones around. Seem to do a lot of research on roofs not to be a roofer. Must have had to look this up just to prove that you might be correct. Lol make sure you look it up how to put your roof on too and let’s see how well that goes.

 

[WRM]

Lol dude I really good not care less either way you’ll be calling a roofer to install it on your house. Hope you pick a good contractor because there’s a lot of not so decent ones around. Seem to do a lot of research on roofs not to be a roofer. Must have had to look this up just to prove that you might be correct. Lol make sure you look it up how to put your roof on too and let’s see how well that goes.

About the response I'd expect, I guess. I've been around the industry for over 30 years. I try to be an informed consumer. I don't need to be a roofer, as the labor cost, in my opinion, is not that bad on my house to justify me doing it myself (and it's a huge job). It really is the materials that keep going up and killing me (ie tariffs, inflation, supply shortage).

Again, it's physics. I don't need to "look those up", and the physics are what they are, so it's not whether "I am correct". The physics are correct, and they always will be. Other than quantum physics, the rules are immutable. I don't pretend to understand quantum physics (and even Stevie Hawking doesn't), but the rules involved about what we are discussing have always been there and they aren't really that complicated.

 

[WRM]

I'll give you an easy science test:

Turn your stove burner on high.

Put your hand a foot over it. Take the temp of your palm with a laser thermo. Write it down.

Repeat above at three inch decreasing intervals.

Now, put your hand flat on the burner.

As you head to the ER, think about how that worked. Your 98.7ish hand came in contact with a hot surface only momentarily. Yet, physics prevailed and heat "went where it's not"--to your palm and as much of your hand as you could stand. Oh...you did take your hand off, didn't you? Do that now, if not.

 

[pcolapaddler]

We had a metal roof installed on our house pre Ivan. A tree fell and bent a couple panels during Ivan, but no other damage.

So far out is still doing fine. Some sun fading.

Contractor missed getting some screws tight. Other than that it has been a good experience.

An additional benefit is that squirrels don't seem to like walking on it. When it was new, they would slip and slide off.

Sent from a handheld tracking device on a remote body of water in SE Alabama.

 

[WRM]

Some sun fading.

Yeah--a concern I have. My wife wants a bronze color. The roofers say the ones you see that have full on delamination are certainly the result of the use of "seconds" rolls. But, you can't put even the quality stuff out in our sun and not expect to get UV damage. Fading will happen, I guess.

 

[DoubleDee]

Get whatever you like. Doesn't matter how long it lasts because if your roof is in the average age range in Florida the insurance company will cancel your insurance. My roof was replaced after hurricane Ivan and I just had it replaced November 2021. Two weeks later the insurance company cancelled my policy effective the renewal date due to my roof exceeding the average age expected in Florida before replacement becomes necessary. My roof was 17 years old when I replaced it. Not a McMansion, 1900 square foot hip roof brought up to current code, 16,900 bucks. Insurance company doesn't want to see the contract, proof of payment, only pictures will be accepted. I am less than overjoyed with insurance companies. Rant over. Sorry if off topic but I just don't believe it matters how long a roof should last unless you are self insured and I am considering that.

 

[WRM]

Get whatever you like. Doesn't matter how long it lasts because if your roof is in the average age range in Florida the insurance company will cancel your insurance. My roof was replaced after hurricane Ivan and I just had it replaced November 2021. Two weeks later the insurance company cancelled my policy effective the renewal date due to my roof exceeding the average age expected in Florida before replacement becomes necessary. My roof was 17 years old when I replaced it. Not a McMansion, 1900 square foot hip roof brought up to current code, 16,900 bucks. Insurance company doesn't want to see the contract, proof of payment, only pictures will be accepted. I am less than overjoyed with insurance companies. Rant over. Sorry if off topic but I just don't believe it matters how long a roof should last unless you are self insured and I am considering that.

They ain't in business to pay claims, and they got hammered for years under a statute that required them to replace a "damaged" roof, no matter how old and ratty and without any depreciation. Truly was the golden age for the consumer. Cheap rates and you never need replace your roof. That statute was supposed to get changed, but I don't know if it did.

Last time I bothered to check, my yearly premium was going to be over $7k with a 20% deduct. Absent catastrophic damage, they'd likely never have to pay me jack. Then, they'll try to make you poney up deduct on front end, so I'd need to have a spare $100k or so lying about to rebuild, given bringing a large 1952 house fully up to "current code". That's a joke cuz this house is built like a Sherman tank. I just go bare.

I think it's on topic because it all goes into the hopper. I feel a metal roof will serve me well to help prevent/mitigate future storm damage. I'd hell of a lot rather buy it than insurance.