Dumber than lumber
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- Dec 19, 2015
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What are the pros and cons of switching to metal when the asphalt shingles wear out? Again.
School me on Metal roofs
- Thread starter Dumber than lumber
- Start date
jkeyser14
Well-known member
What type of metal? Standing seam or corrugated?
Standing seam: 50 year warranty on the paint, will easily last 60 years without repainting (or longer if you go with aluminum or copper instead of steel). There is zero entry points for water, so you will never have a leak (if installed correctly). Can have insane wind ratings (150+mph). Insane fire ratings too. Downsides: Cost, need snow guards or snow slides off the roof and can hit people below, and did I mention cost?
Corrugated roofing: Cheaper than standing seam
Cons: Uses fasteners screwed through the panel that can be prone to leaks. Often need to be retorqued or have washers replaced. The finish also doesn't seem to last more than years, but that might be because they are generally lower cost products
Standing seam: 50 year warranty on the paint, will easily last 60 years without repainting (or longer if you go with aluminum or copper instead of steel). There is zero entry points for water, so you will never have a leak (if installed correctly). Can have insane wind ratings (150+mph). Insane fire ratings too. Downsides: Cost, need snow guards or snow slides off the roof and can hit people below, and did I mention cost?
Corrugated roofing: Cheaper than standing seam
Cons: Uses fasteners screwed through the panel that can be prone to leaks. Often need to be retorqued or have washers replaced. The finish also doesn't seem to last more than years, but that might be because they are generally lower cost products
chaosracing
Well-known member
jkeyser14 pretty much nailed it.
Anytime you can go hidden fastener on metal roofing, it will last a very long time with no problems. But the cost is higher.
Corrugated (or agricultural panels as mostly refered to) have exposed fasteners, that over time the washers break down and will leak. Not a big deal as you can remove and replace just the fastener. But it will keep happening.
Finishes are better today, but not as good as Kynar coated standing seam roofing. Cost is still higher than asphalt shingles.
Anytime you can go hidden fastener on metal roofing, it will last a very long time with no problems. But the cost is higher.
Corrugated (or agricultural panels as mostly refered to) have exposed fasteners, that over time the washers break down and will leak. Not a big deal as you can remove and replace just the fastener. But it will keep happening.
Finishes are better today, but not as good as Kynar coated standing seam roofing. Cost is still higher than asphalt shingles.
Jazz1
Well-known member
Depends how old you are. If you're 60, do you really need 60 year roof. I'm having my garage re shingled this summer.
danski0224
Well-known member
The trick would be getting it done in such a way that caulking isn't the primary water intrusion seal. Good luck with that.
I respectfully disagree here. My roof is no more noisier than the shingle roof it replaced.
JoeMcGov
Well-known member
There is:
* screw down. It attaches to your roof framing via a direct surface applied screw. Usually has a neoprene washer. So you put holes in your primary roof material. Can usually get in several thicknesses with 24 ga and 26 ga being commonly offered. Can usually get in galvalume ("silver" look) and for some manufacturers in colors (that themselves can have differing levels of quality).
* standing seam. The roof panel attaches to a clip. And the clip attaches via screw to your roof framing. The length wise panel-to-panel seam is then crimped together and further crimped to the clips thereby completing the attachment to the roof framing. If you have long length-wise runs that require more than a single panel in length then you will have an end joint. These usually get a direct "stitch" screw connection. The materials vary from traditional galvalume ("silver") look to painted to baked on Kynar colored finishes. Come in incredible selection of colors and usually 22 ga, 24 ga and 26 ga.
These materials will vary wildly by roof panel manufacturer as will price.
Must pay micro attention to changes in planes and how you detail/flash them for proper water tightness. Most manufacturers will have their details that address most situations.
There's still a lot to learn beyond these simple primers.
In the commercial building world Metal Building Components Inc. ("MBCI" in the industry) is a well known and respected supplier. You can poke around their website and see a few things. http://www.mbci.com/
* screw down. It attaches to your roof framing via a direct surface applied screw. Usually has a neoprene washer. So you put holes in your primary roof material. Can usually get in several thicknesses with 24 ga and 26 ga being commonly offered. Can usually get in galvalume ("silver" look) and for some manufacturers in colors (that themselves can have differing levels of quality).
* standing seam. The roof panel attaches to a clip. And the clip attaches via screw to your roof framing. The length wise panel-to-panel seam is then crimped together and further crimped to the clips thereby completing the attachment to the roof framing. If you have long length-wise runs that require more than a single panel in length then you will have an end joint. These usually get a direct "stitch" screw connection. The materials vary from traditional galvalume ("silver") look to painted to baked on Kynar colored finishes. Come in incredible selection of colors and usually 22 ga, 24 ga and 26 ga.
These materials will vary wildly by roof panel manufacturer as will price.
Must pay micro attention to changes in planes and how you detail/flash them for proper water tightness. Most manufacturers will have their details that address most situations.
There's still a lot to learn beyond these simple primers.
In the commercial building world Metal Building Components Inc. ("MBCI" in the industry) is a well known and respected supplier. You can poke around their website and see a few things. http://www.mbci.com/
diesel_dan
Well-known member
I'm out in Fire Prone Kalifornia, I have a concrete tile roof on the house and metal on the out buildings. If I built it myself (or had it built for me), metal all the way... Insurance only gives me a little over a shingled home, hot embers don't stick to the metal roofs so easy... Make sure your installer knows how to install it!
Good luck
Good luck
danski0224
Well-known member
The material can be run-off on site in almost any length.
+10,000 on the details. The details can sink a very expensive metal roofing job.
I had standing seam installed two summers ago. I was surprised at how detailed and tedious the installation is. My house is funky shaped and low slope, which complicated all the valleys. If you come across any good installation manuals, you'll see how folding and tucking panels is necessary (not just slapping them down). The goal to avoid any exposed fasteners or rely on sealants. It took two solids weeks of a full crew working 8 hours a day to install. They weren't slacking either. I love the look. I took a bunch of pictures during the install. The center of my house is vaulted with no attic space. It is indeed louder. The sides with attic space are just slightly louder than asphalt. It may have something to do with the low slope.
Attachments
That's why I asked if its insulated, might make a big difference.
I have an open screened in porch with shingles, walk from there to shop with metal roof and ceiling, you can definitely hear the difference.
I know two people that switched to metal on their house, first thing they said, its louder.
bradpac
Well-known member
A metal roof on a solid roof deck like plywood or OSB really isn't that much louder, inside a finished house you won't notice a difference. With open framing or a lathe system with no insulation like a shop or porch the difference is much more noticeable.
We changed the roof on our old 1929 house from the original Asbestos shingles to a snap lock, hidden fastener metal roof and didn't notice a difference. Although it did lower our electric bill in the summers a bit.
Spareparts
Well-known member
Thinking about replacing my asphalt shingles for metal on my shop, first thing I was told was don't just overlay the metal on the shingles, the movement of the metal on the shingles will cause the bottom side of the metal to rust and fail. My neighbor did his shop in metal and they put down a barrier before the metal and it looked like bubble wrap, they told him it would make it a lot quiter, and it did. Havent decided yet on mine
Bretny
Well-known member
As for metal over shingles you can put furring strips down nailed to the framing. At some point though your replacing the roof for a reason and it more than likely will need some sheething replaced. Just take the shingles off.
theoldwizard1
Well-known member
Q for the experts. I have heard that metal roofing should never be applied directly to plywood/OSB decking. The decking should be cover with tar paper (or better yet, ice and water shield), furring strip applied (spacing ?) and the the roofing attached to the furring strip.
The idea is, it lets the decking "breathe".
The idea is, it lets the decking "breathe".
bradpac
Well-known member
Standard felt or a synthetic underlayment directly on top of a solid plywood/osb decking is the most common and will give you the best looking install.
I have seen some architects/installers down here in TX install them over a diagonal lathe or some kind of vented material to prevent thermal bridging and ventilate under the panel. This type of thing is more common with a sealed attic system where the underside of the decking is foamed. Over the past 15 years that I have been working for a metal roofing manufacturer, I have yet to see any real evidence that this actually helps anything. For my house, I didn't bother.
jkeyser14
Well-known member
The furring strips aren't neccessary, but the tar paper or synthetic underlayment are neccessary. You can get small amounts of condensation under the metal panels, the underlayment makes sure that the decking underneath the metal doesn't rot or grow mold.
Allen Arin
Member
The Pros for having a metal sheet will be
1-longevity they last upto 40-70 years depending on the material
2-durability they can sustain wind gust there are less chances of getting cracked abd they require less maintenance but they should be inspected periodically
3-they wont spark and ignite into flames on lightning strike
4-they are environmentally friendly
There are some disadvantages too
1-You have to spend 2 to 3 times of dollars on it as compared to asphalt
2-they make noise a lot during rain or hailstorm
1-longevity they last upto 40-70 years depending on the material
2-durability they can sustain wind gust there are less chances of getting cracked abd they require less maintenance but they should be inspected periodically
3-they wont spark and ignite into flames on lightning strike
4-they are environmentally friendly
There are some disadvantages too
1-You have to spend 2 to 3 times of dollars on it as compared to asphalt
2-they make noise a lot during rain or hailstorm
fitter30
Well-known member
Purchased a house with a shingle roof that was baked and osb decking coming apart from the heat. Used 30 lb felt, 1x4s to built a ladder type frame screwed barn siding through metal 1x4s into truss. That was 14 hears ago. House is a modified A frame a 12/12 pitch. Loft was so hot when we moved in 95* outside 95*+ inside. After didn't measure temp but there was a big difference.
Bretny
Well-known member
You cant say your metal roofing allowed for a cooler inside temp. You can say you allowed the back of it to vent thus making it cooler.
cbacres
Well-known member
I stripped the shingles on my shop roof, installed peel and stick underlayment, 1x4 wood screwed through plywood into the trusses.
I used PBR galvalume panels. The air gap under the steel helps a lot with the heat transfer into shop.
Over 15 years ago I built a barn with the same panels, on 2x4 purlins, no sheathing. Had only one leak and that was due to missing the edge of purlin.
I used Zac fastners, it's a steel screw with a zinc head that is like a inverted cup over the rubber washer. They hold up great. It's important that the fastners be seated , the rubber compressed just right.
I used PBR galvalume panels. The air gap under the steel helps a lot with the heat transfer into shop.
Over 15 years ago I built a barn with the same panels, on 2x4 purlins, no sheathing. Had only one leak and that was due to missing the edge of purlin.
I used Zac fastners, it's a steel screw with a zinc head that is like a inverted cup over the rubber washer. They hold up great. It's important that the fastners be seated , the rubber compressed just right.
I have a house built in the early 50's and the roof sheathing was 1 x 5's and I stripped shingles and sheathing. After laying down 5/8" plywood, I installed the (metal roofing)underlayment then the metal roofing.
The thing with the specific underlayment is it's good for several months by itself plus the rolls are wider than felt. It covers quickly.
As I've said before, no more noisier than the shingles in hard rain.
The thing with the specific underlayment is it's good for several months by itself plus the rolls are wider than felt. It covers quickly.
As I've said before, no more noisier than the shingles in hard rain.
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slodat
ALLIANCE MEMBER
I have Rolled Steel Products Loc-Rib on my shop. No exposed fasteners. I'm quite happy with it.
KMinAF
Well-known member
Best decision that I ever made was to go with metal roofing. One caveat however is 30 seconds after you have finished shoveling the snow off your driveway I guarantee that you will hear a loud swoosh sound and find a 3' berm right in front of your garage door. Installing snow dams is highly recommended
shortykorte
Well-known member
And I thought the sound of rain on a tin roof was a good thing. [emoji16]
My commercial building has screws. After 25 yrs I’m getting intermittent leaks. I need to check screws more closely when I clean leaves off the roof next time. Florida rain isn’t that bad but an acorn hitting the roof will get my attention.
Shorty Korte
Always remember quality in QST
Sent from my iPhone using Garage Journal
My commercial building has screws. After 25 yrs I’m getting intermittent leaks. I need to check screws more closely when I clean leaves off the roof next time. Florida rain isn’t that bad but an acorn hitting the roof will get my attention.
Shorty Korte
Always remember quality in QST
Sent from my iPhone using Garage Journal