Been seeing the Amish putting wood strips on roofs and then a metal roof.
Would this be considered good practice to go to metal from shingles?
This is the answer.
Wouldn’t it add extra insulation? Is the downside you don’t know what’s under it or are their others? Not a roofer
Not likely heat, but the sound deadening would be great. The cheap bastard that built my house didn't put anything under the steel. The living room has a vaulted ceiling and a decent rain makes too much noise to carry on a conversation.
Cheap bastard (and incompetent) built my house too.
Pretty sure he built most houses.
I did this and it improved the roof greatly.
I jogged the lateral slats to add stiffness and rigidity to the entire roof.
It's great sound insulation, and nothing gets under it the sides are all sealed.
It also creates an air gap between the shingles and the roof which acts as thermal insulation. I would describe it like the roof of the house constantly being in the shade, even if it's not.
This tactic is recommended by our best local metal roofing company, obviously as long as there are only one or two layers of shingles though and there may be other considerations.
Asphalt shingles offer very little in the way of thermal insulation.
What is essentially happening here is the owner is covering up garbage on his roof with a new metal roof in order to save a few hundred dollar-bucks.
If there's rotten boards or holes in the shingles, they'll stay that way until the next owner comes along to fix the original problem.
It tells the world that the homeowner is cheap and inconsiderate.
What if the owner is rather generous with his time and money but he works a low paying job that just covers bills and just doesn't have the extra money to even fix the roof or remove the old roof? What if his insurance company is forcing him to change the roof or drop him?
Let me ask a question if a metal roof costs $20k or $30k what's the avg profit on that and how many days would it take to complete? Let's say typical 1500 SQ ft.
Metal is one of the more expensive options; if the owner is of limits means, they’d be putting a new layer of shingles on top. This is 100% and always an effort to just save the money that a tear off would cost.
How much more could a tear off really cost on a little roof like this?
Still has a cost, no matter if it’s just a few hundred. Plus when you get those shingles off, I’d put money the decking needs to be replaced. They’re hoping to avoid finding problems and that the metal will outlast them.
It's more then a few hundred bucks just to haul the trash to the dump shingles are heavy as fuck
Nah. Just get a Yard-A-Pult. Your neighbors won't know what hit them! :-)
and you have to haul away the shingles.
This is an important point about the extra cost and hassle of a tear off. Seeing if your actual roof is intact or not.
The tear off is only part of the cost, the labor.. The dump fee is the other hidden cost.
Never held a single shovel, huh? That little roof could take a long time, especially if you don't want to drop nails and shingle shit on someone's yard.
People be exaggerating a bit too. Yeah, it is best practice to remove the old shingles, how else are you gonna repair rotted decking, but if the roof wasn't leaking bad or for very long, chances are damage is minimal and you can slap some metal on it. Although I hate metal roofs.
Continuing hypothetical scenario. He’s also a long term thinker so considering metal roof.
But he isn’t. A long term thinker would be concerned with hidden wood rot under his new metal roof.
When we replaced the metal+asphalt on my dad's house, we had to replace more than half the decking. I replaced the metal roof on my own house and needed to replace half the decking as well, and I didn't even have asphalt underneath. I think a study needs to be done on thermal dynamics and humidity, whether there is some moisture capture going on, or condensation on the wrong side of the metal.
As it goes. I had to replace around 10 decking boards when we replaced our roof last summer.
Until you put eyes on each board specifically, you never know how much rot is lingering underneath.
There’s been studies. Metal in contact with wood on a house will ‘sweat’ or collect moisture on the underside. The metal needs a high temp vapor barrier, and also the attic should be properly vented to prevent moisture. If course there are some exceptions but this is generally the rule
Gotta share when you smoke the good stuff or everyone else in the room thinks you are just a bit strange.
No this is a Normal practice if your shingles aren’t to cupped /wore out, cut off over hanging shingles lay down strapping nailing them into the trusses. Any weak spots in the roof generally don’t matter as the strapping and metal sheet will take the support not the plywood underneath ( on a new build ,barns,shops garages with metal roofs don’t have plywood most of the times just the strapping and tin ) I have roofs that I have done 35 years ago and they still look basically like the did when we first did it
Finally a proper answer.
Dollar-bucks, eh? r/unexpectedbluey
It certainly adds extra weight
Absolutely that answer. The roofer doesn't want to scrape it and haul away the old shingles. It is just lazy.
Yea it doesn't really up the price that much especially with a roof that size it's only a couple hours of ripping and prep and few hundred for dump fees
Doesn’t up the price much? I’ve gotta quotes to do both on a house and typically it’s between 25%-35% more to include removal of the asphalt
If it's the Amish, that's a LOT of work for them to dispose of. No trucks, only horse carts etc
What's the downside though?
The Amish would hire someone to do the hauling. They don't mind working hard, but they're not gonna work stupid! Especially if they are doing the work for someone else and getting paid for the job.
I run into a lot of patients that work for the Amish. They hire a lot of things out. I had a patient that was a bus driver for the Amish. In the morning she would pick up the kids and take them to school, then pick up the adults during the day and run them around town, then pick up the kids in the afternoon. Sounded like a good gig she had going for her. She said it was a small Amish community of 13-14 families and she drove them al around in her passenger van.
Modern Amish and Mennonite in my area of PA have a driver that hauls them and their shit around. He usually sits in truck and sleeps while they work and answers the Amish owned cell phone
That sounds like a sweet gig.
Until you have to sit in a 12 person van with a bunch of dudes who work outside and with animals all day and don’t own showers, otherwise pretty easy work, and comes with a variety of baked goods on occasion
A local boy kicked me in the butt last week....
I just smiled at him and I turned the other cheek
I really don't care, in fact I wish him well
That's not how the Amish work. They just have English to drive the trucks.
The Amish around here have people drive trucks and trailers for them. Some one drives them to the job site too
The Amish typically just have a dumpster delivered
For the most part, structural integrity. If the asphalt is already damaged, it’s like having a piercing in your skin. Something already got inside, and if it’s infection (sheathing and other important structural pieces failing), you will have a bigger problem in a couple years.
However, in your scenario, in which there aren’t resources to do so and if you know the sheathing and other structures are 100%, you don’t necessarily have any negatives other than maybe reduced heat radiation (or better even lol but that’s a pro).
It’s not the best practice, but it is the most cost efficient, and really won’t be detrimental to the life of the roof or roofing. I’d want my old shingles removed prior so I can ensure the roofing is not rotted anywhere, but if your sure it’s good then it’s preference.
How do they get the correct fastener pattern for either a standing seam of 5v crimp? In places with high winds, the fasteners seem to be 3 to 6 inches on center?
I'm sure this will be an exposed fastner steel roof which typically is 2ft on center or 16inch on center. I don't do alot of standing seam but I would assume it's better to sheet with thick enough plywood so you have lots to fasten to and nice flat surface
It offers sound reduction and importantly it adds fire protection to make your metal roof a class A . Otherwise you need to apply special fire rated underlayment for the same fire rating. Something to think about.
Probably a lot better for sound. Rain on a metal roof will annoy you. For a normal house, I would leave the shingles and add some foam board before installing the metal roof. Eliminate the sound transfer into the house.
Is it common for homeowners to choose the cheapest options?
Only the cheapest homeowners...
Financially strapped homeowners (who are cheaping out) sometimes make do due to limited resources and hope things don’t go sideways. As a salesman once said, “you have to be rich to do something twice.” He initially said, “you have to be rich to buy cheap windows,” and then explained his logic.
Nothing is worse than seeing these construction subs and knowing someone’s gonna be tearing the work out sooner than the owner ever expected.
Note: Fabral has instruction manuals for installing to furring, installing to deck and over existing roofs. I believe warrantiesgo out the windoware harder to have honored on existing installs.
back to this post
Directly from Fabral’s website regarding this issue:
Can I install metal panels directly over my old, worn-out shingles? Since metal weighs only 1/3 as much as shingles, you can often attach metal panels without tearing off your existing shingle roof. This eliminates the cost and problems of disposing of the old shingles. The best way to do this is to attach 1″ x 4″ or 2″ x 4″ furring strips at 24″ o/c parallel to the eave and ridge. Check local codes to determine if tearing off shingles is required in your area. Request Fabral’s Technical Bulletin #721 for additional information.
I used to sell Fabral (in a limited scope) and I wrote warranties going out the window is not exactly the best way to say it. If the roof and decking have issues of being out of plane (warps, gaps, protrusions) Fabral might have a rep check the installation to see if the panels are deformed out of tolerance or outright crimping along the ribs. Crimping usually is a result of transportation and handling and not of installation, but contractors hope homeowners don’t notice. 😡
Crappy install = warranty out the window. So if the purlins are installed and shimmed beautifully on the existing roof, the warranty might just be intact. I only had a few warranty calls and they took up to three months for the rep to come out.
Why, scrape shingles that work well enough, and cover it with steel. So if the steel roof ever leaks you already have a second roof to shield you? It also greatly helps when it rains with the sound by greatly reducing the sound of rain on a steel roof. It only needs to last another 5 to 10 years as everything will be incredibly difficult and terrible in the future.
Ya a second roof full of holes dummy lol. If installed correctly onto the decking there is no real “sound” as there is no echo chamber under steel.
Are you doing well in this economy?
Arguably really.
Yes people do it all the time…also see people do it all the time and mess it up.
Yes
That's how mine was done a couple months ago. One other point they made which I don't see here yet is the shingles will at least give you a tiny bit more soundproofing as well. It's definitely quieter than the other side of my house which has nothing under the metal
Soundproofing is the reason I've heard for keeping it on.
Noise reduction, heat/cooling retention, extra layer of leak protection, as well as dent resistance. The correct way is to take off the shingles, but I kinda prefer them on if they’re in ok shape. If their in shit shape, tear it off
Not tearing off doesn’t save a whole lot of cost. It’s the lazy way to do exposed fastener if you want to do exposed fastener although not recommended
When the exposed fasteners fail, does the asphalt roof offer a minimal second stage of protection?
In a sense, yes. A good thing to keep in mind is if there is existing or hidden damage below a potential hole in the first layer of protection, water will obey gravity and find its way down. At that point you are removing panels to find a secondary leak in old shingles; while possible would be an utter pain in the ass and a massive repair bill
Remember that a roof only works if it doesn't have holes in it. All roofing products consider this carefully so they are usually designed to hide the nail completely (asphalt) or to have gaskets around the fastener. By placing a bunch of things on top of the roof and screwing them with nails, then you are creating a bunch of holes around every screw/nails shaft and the asphalt roof. Once the metal roof is removed, then you are left with even bigger holes once those screws/nails are removed, because now it is just holes. So no extra protection. There is the possibility of insulation benefits, but insulation works better on the bottom of the attic not the top, so I am not sure how much benefit.
I'm not a professional in roofing but with basic knowledge I'd say no as if a fastener fails, it is now just a hole in your roof, even if part of it remains there's now long the seal between the roof material and the fastener head. Which leads to possible leaking. May not be substantial with the under lying asphalt but if the water can reach the OSB then it will slowly start damaging the roof.
And now you have to remove two roofs! Lol.
I’d say it’s the best practice provided there’s only two layers. What’s the harm? The shingles further protect the roof and insulate the home. The costs are kept down, and waste disposal is deferred to another time. Idealism about how this is lazy, harmful, and a bad idea is bullshit imo.
Yes, but. They will simply slam down the metal roof on top of any existing damages. Any damage under those shingles will still be damaged when the new roof is installed. If you know there is no damage, then great. Otherwise...
But now that damage is covered/sealed by the metal roof isn’t it? What could happen?
There’s the right way and the cheaper way, people have opinions then when it’s their time to pay they pick the cheaper way most of the time.
You know this really needs to be said more often. Contractors often, under direction of the owner, do things cheaper ways then we like. If the contractor feels big enough, then they can start demanding quality. Not everyone can start their business that way and not every owner wants a contractor that demands quality. For example, I heard many contractors talk shit about putting on a second layer of asphalt shingles. This is what some owners want and it's their decision. We can say no, but they can find someone else that will do it. I think us contractors judge each other too much at a glance when really we don't know the details of the job and the owner.
its not a very good idea. i mean if you are going to do it this way at least remove the ridgecap and see where the rafters are so you can secure your furring strips to rafters and not just decking. where i live we get pretty regularly 70-80mph at least once a year. ive seen 3 roofs in about a 5 year span that have been peeled off like sardine cans because the contractor decided to just nail furring strips through however many layers of shingles into decking
Works great on a retrofit. Take off he shingles where needed. Like the peak and caps.
The sheeting and framing needs to be solid. Yes - you do see this.
Very common to do perlings over shingles then attach the metal to the perlings
Yes, actually most customers prefer the extra protection, if done properly, it's not a problem
MOAR LAYERS = MAX PROTECT!
Or something.
Owner probably was on a budget but once it’s installed it’ll still work as intended
We had a major hurricane blow through here in 2023 damaging a ton of roofs. Almost everyone I know, including us, had metal roofs installed and all of them were installed over the asphalt shingles. Additional cost to strip our roof was $1,500. I don’t see the downside?
It is common. Saves on the tear off and dump fee’s. There aren’t any downsides that I’m aware of as long as the deck underneath is in good shape.
I’ve never seen it done any other way, at least where I’m at.
Yes
It is common, weight is only issue. Single layer asphalt perfectly fine to metal over.
Ionno. I own my home and will likely switch to metal on the next upgrade. The metal doesn't care what it's covering. If it's waterproof enough to go on the deck it'll cover old shingles fine.
Is it perfect? nope. New construction would be putting it on the deck. Will it cover shingles just the same? yep.
Not everyone has the money to pay for every option when you buy shit. Sometimes people buy cars without the upgrades and all the options, roofs are no different. Homeowner probably saved 2500 bucks. The metal will outlast him and he's got 2500 to spend somewhere else.
When i have my roof done i'll likely do the same. I'll have metal put on over my 3tabs and it'll outlast me. If i didn't have 6 kids and a grandkid on the way along with all the other daily bills I would likely have 30k to drop on a perfect replace. Guess what. Life is expensive.
About the most common practice for laying metal roofing
It’s funny how much the comments are all over the place on this. Perfectly fine to go over asphalt, check the decking be walking on it and inspecting the shingles, replace the deck if soft. Must use strapping to keep the metal from getting abraded on the asphalt with the expansion and contraction. Fasten the strapping to the roof trusses with 2.5” nails. Space the strapping 2’ on center and fasten the metal to the strapping with 1.5 ( or 2”) this way the metal is positively connected to trusss and decking.
Help me out, why bother removing shingles if you're just going to do this?
The furring strips help immensely. If it was directly on the shingles, that’s a bad job.
If the existing roof is in good enough shape then putting metal over it is fine. You gain some extra insulation with both layers and save money not having to remove the shingles. That's how I did mine.
I did it on my house, saved a couple thousand bucks in tear off, cleanup, haul away. Original roof was on but had hail damage, been years now with no issue and it's a whole bunch of shingles not in a landfill somewhere. 🤷
It's also quieter when it rains than it was before (everyone's favorite comment/question - isn't that loud when it rains?)
I think it's totally fine.
Common
In 30 years someone will rip off the metal roof and find the asphalt shingles and be so happy like the won the roof lottery. You see this with carpet and hardwood floors all the time
/s
My ex just paid $25k for a 50year shingle roof. They had to replace 70 sheets of plywood. And one of the workers put his foot through the ceiling into the kitchen.
My dad did this to his house and I regretted it after he died and it passed to me. I ended up removing all the metal, plus most of the decking, and replacing the roof with new asphalt shingles.
If the roof is leaking you've got a compound problem, and contrary to what they say about metal rooves, they don't last '40 years' without any sort of maintenance. The clear coat dulls, paint flakes, metal rusts, and the rubber washers on the screws degrade and allow leaks. I can't prove it but I have concerns about condensation issues on metal generally.
Shingles deaden the sound. Metal roofs can be noisey.
It leaves an airgap which is a good practice I guess. Asphalt shingles can be put on 3 layers before it has to be stripped off.
It’s honestly a less expensive roof. It saves thousands not having the tear off costs you would normally see.
Yes .. and no.
Let the next guy deal with it syndrome
It is, mostly in the sticks but it’s relatively common. Like someone else said, there’s better ways to do it.
Yes
I don’t know anything about roofing, but Iv seen people do this before. Iv also seen more and more people slapping metal roofs right over shingles and everything, I’m not sure if that’s normal or not. As I said, I don’t know anything about roofing.
Belts and suspenders?
2 roofs are better than one
Truly not saving that much money either
Yes
I’ve seen this many times but for me a definite NO. Ask a fireman what he/she thinks of dealing with two roofs with an air gap between them. (I would call it a chimney between the layers). 😉
Would there be any benefit to leaving the old shingles on under a metal roof? I would think that if there were any leaks in the screws of the metal roof, that the asphalt could act like a second layer of protection.
I've done plenty of roofs in the past where the choice of whether to tear off old shingles was not ours to make.
The proper way is to remove the shingles. All depends on what the homeowner wants to pay for.
In most places as long as it’s just one layer of shingles it’s to code. Would a roofer recommend this? No, most wouldn’t.
Yes but a layer of 30lbs felt paper is needed in-between the shingles and the metal because the metal will for ever expanding and contracting due to temperature change the rocks on the asphalt shingles will scratch the metal and it will rust from the underside up in a surprisingly short time compared to the life expectancy of the metal roof
I installed a new shingle roof, then overlayed metal like this. My house is on top of a tall hill and it can get extremely windy - shingle roof alone would typically last 1-3 years before wind took shingles off. In my case this provides an increased level of protection since I’m very rural and hit it takes months to over a year to get anything done.
I would leave it. That way when the fasteners and valleys leak in a few years the mess won’t show up inside
Had a roofing “contractor” put a metal roof over existing shingle on home surrounded by trees. Within 3 years the damned thing had rotted through all the decking and some of the structural supports of our roof. Fixing that hack job was so expensive.
Yes
In my area, code allows up to two layers of roofing, whatever type it may be. You just have to pearl out the whole roof to put a gap between the shingles and steel.
Probably not the best idea? A lot of times building code won’t let you go over 2 layers thick of roof. At that point stripping is mandatory. Or they will make you do it after the fact.
It’s the broke practice
I live in ME and my metal roof was installed 21 years ago when my father owned the house. Roofers ran strapping over the shingles and installed the metal on top. Haven’t had a single issue with leaks since that day.
May not be the BEST way to do it, but it certainly isn’t the WORST.
Short answer: yes it's common.
This is super common where I live. So common I’ve never seen them take off the shingles to do a metal roof. Their marketing is genius for it, basically they talk about saving money by not having to remove the shingles, also being more green because they aren’t ending up in a landfill. No risk of nails being picked up by your lawnmower and it speeds up the install.
Sure bullet proof roof most towns two to three roofs on top of old
My metal roof was installed right over top of the existing shingles. It's a common practice.
Commonly done. Not for the best.
Yea, not exactly the best way to do it, but it happens a lot.
Let’s say the substrate is in good shape, single layer of asphalt I say no problem I’d strap with the rafters then run the nailers on 12” perpendicular
Yeah.
It becomes more common when you haggle down the price.
My question is does it impact the manufacturer warranty. I have no idea myself; but read the fine print.
Fire fighters hate roofs like this.
There's a rich way, and an affordable way. Doing it right, accomplishes the goal and fits your means.
There's no shame for the laborers who aren't fairly compensated. The shame is instead on those running the corporations and perpetuating these abuses.
Sadly, getting paid fair compensation isn't very common.
Help the economy, pay the person not the position.
and/or
Escape Crapitalism
If you tear the roof off, you need to cover the entire roof in a vapor barrier anyways, so why not just use the old shingles?
It’s common, but it’s not the best idea
Problem is if there is any water damage to the roof it is not being resolved
Yes.
Very common.
It makes sense pictured install method would leave a small air gap (the depth of the furring strips)between the metal roof material and the asphalt that should provide a bit of an advantageous insulation..(especially in the heat)if vented properly.Metal roofs are awesome.
You have to consider thermal dynamics when designing an overlay as pictured.
Yes. I have a family member who had to hire an asphalt shingle company to rip off their old roof because the company doing the metal roof wouldn't
We have a house in Deep South Texas that gets 18” of rain annually. We put metal roof over shingles. Now I read this thread!
I’m not too worried since we get so little rain. The big enemy here is the heat where it’s 100 degrees 6 months of the year
In my area it is very common, but they put it right on top of the shingles, no wood strips. No one wants to peel a roof, plus they don’t want to pay for the fancy waterproof fittings for stove pipe and vents. We have strong winds and not a lot of rain so it works if they put in enough screws in the right place. Don’t think the metal roof warranty is honored.
Yes it is common practice. I would striP of shingles first and make sure roof sheathing/ planking is in decent shape. Then purlin up and steel.
For some reason it is the new trend. In my area
I was told a very interesting fact by my mom in Arizona. I am trying to figure out who is making the rules or getting their pocket filled. The homeowners insurance policy will no longer cover roof damage with these clauses. 1 if you are going to replace with asphalt shingles without a complete strip of the roof and plywood inspection. 2 You can get a metal roof applied directly. I may understand metal roof for wildfire concerns but I may have a stupid question about a roof becoming combustible in 120degree weather with asphalt shingles and metal on top. Does any one have any thoughts on this?
Yes, the asphalt shingles are left for insulation purposes.
Good chance your home insurance will increase. Get rid of the asphalt roof it is more combustible material than one needs on their home.
Ya, when your cousins brothers best friend who knows a guy…
where i am old house got like 5 layer of shingles on top of each other... also that roof in OP picture doesnt look healthy, its all crooked.
Just keep adding it. The sky is the limit.
Yes this is normal. Nothing wrong my with it no matter how many say “you have to tear it off first”.
My roof was done this way nearly a decade ago. Absolutely zero issues. I'd seen several other homes in the area done this way. The contractor didn't even mention removing the shingles. (He did ask if there were any leaks.) Unless you had a leak I would see absolutely zero benefit to removing the shingles. Are these folks suggesting that you tear everything off down to the rafters? Seems like rafter, sheeting, felt, shingle, steel would be better than steel in a lot of ways. Maybe I'm just dumb?
Depends how many layers. I have a layer of Grace ice and water shield, a single layer of asphalt shingles and we put the steel roof over top. We could have removed the asphalt shingles but that would have meant replacing the Grace which is quite expensive and one layer of shingles is no big deal
Don’t question the Amish.
If you suffer from meteors a lot this is recommended
Still looking for the medal roof to pop out
As long as there isn’t multiple layers of shingles, are flat, no nail pops, no algae or moss, roof sheathing is in good condition and a new synthetic underlayment is put down there should be no issues with or without strapping. You don’t want any granular surface touching the underside of the metal because the paint on the backside helps prevent corrosion. It is always best though to remove any old roof prior. Local codes may dictate any specific details.
That would be the preferred way. There is no benefit to ripping it to a bare roof unless it has severe damage. This way takes half the time, half the cost, and leaves you a second layer of protection from leaks. It also allows you to use cheaper R-Panel with exposed fasteners.
I would make more of a grid with the first 1X4s going vertical then another 1x4 going horizontal on top of the vertical pieces. That way you achieve above sheathing ventilation and your roof and home remains cool even on the hottest days.
Wait Amish people use electricity?
Yes but also that valley is going to be a problem
Its common and realistically if there is not rot or damaged wood underneath it won't hurt anything.
A few years ago I had both of these layers removed and replaced with a new shingle roof. It’s all fresh now and looks better than the poorly installed metal ever did. (It was powder blue and installed wrong by the previous owner). They also replaced bad decking and installed stormshield which was definitely not there previously.
Common practice for the cheapest bid. Bet the finished product is going to look outstanding
Anyone who says it’s a bad roofing company is wrong. If it’s what the customer wants and they understand, it’s on the customer. It’s not what I would do as I always strip down and start new. There’s a lot of weight in shingles and you add the chance of also pinning in any rot.
Very common
Interesting how many people are criticizing this. It's absolutely fine when done correctly if the asphalt roof isn't already leaking. And it's an extra layer of protection, which is pretty nice in snowy states.
I would likely keep it for it's sound dampening properties underneath the metal roof. One layer of shingles isn't too much weight.
It seems most comments say yes or no based on that fact that the asphalt shingles could or could not be in good condition. But what about the thermal properties of shingles and metal roofs? If your installing a black metal roof it obviously will retain more heat than a white metal roof. But still not as much as a shingle roof because asphalt has a higher thermal mass than metal so a black metal roof still doesn't attract as much heat as a asphalt shingle roof. But if you put a black metal roof over an asphalt shingle roof does this not multiply the thermal properties of the roof system?
Common practice, not the best though. Can’t determine if the roof deck is rotten or not. As well the asphalt shingles underneath will cause water condensation on the underside of the metal panels, lessening the life of the metal panels and causing them to rust/rot because the underside is bare steel. The manufacturer may or may not provide material warranty coverage with this type of install. I always recommend removing any roof layers, and do not provide warranty on any issues caused in later life with this type of install.
As long as the Roof Underneath is sound.It's not gonna hurt a damn thing There's no insulation value whatsoever to the shingles. If decking's good, it's good to go with proper ventilation. Maybe the guys on a budget, what people don't know is that metal Roofs are expensive. Yes, the p Profit. margin is large because it's so fast to put down. It's a big secret they don't want you to know it's a bunch of shit
Beware, insurance companies will drop your coverage for this. The gap between the shingle and the metal cause issues with moisture and you're more likely to have hail damage. I know this for experience...
I helped do this on a structure that due to a very complicated situation, we needed to get a couple more years out of. It needed a lot more work underneath. Ultimately when the property is sold in the next year or so it will be a knock-down based on the statements of the soon to be new owner. It was to buy time.
It's cheaper, it's allowed in many areas depending on how many existing layers, but not the best way.
Roof overs …. I’m not into . The metal is lighter but if you have any rotted wood not advisable
A friend did this with shingles. It didn’t work. The contractor he hired for complete new roof did not take the debris from the other two roofs.
Horrible idea residential applications should have the shingles removed a proper underlay and direct to Deck strapping is for out building that have no roof sheeting nothing good about the way this is being done for more then these reasons alone
Done cheaply, yes.
It's common but stupid. Who says the plywood under the shingles isn't already gone and in need of being replaced.
Mine was put up over the old roof. 25 yrs and still looking good. Never had a problem.
Doesn't need to be torn off. Totally fine. People wanna judge but fuck em
I like Johny Walker Red scotch. It consistent and cheap. I can’t afford $1,000 bottle single batch
Best practice is tear off everything, put Zip roof decking, sealed at seams. Followed by 2” foam panels giving R11. Then steel roof.
But, metal roof over asphalt shingle is fine. Lacks the R11, lacks the sound deadening of foam. Lacks the confidence of waterproof of the Zip. But it’s fine.
My barn has two layers of shingles and a metal roof over the top.
My house is like this (like this when I bought it) and I'm not super happy with it. The shingles underneath are in terrible shape.
That must be one heavy roof if that's asphalt
I did this to my house and here’s why:
When my roof was 14 years old my insurance company sent me a nice letter telling me that my roof was too old and if I didn’t replace the roof they would not cover me.
This struck me by surprise because I figured my roof would have another 5-10 years of life. I shopped around for insurance and no insurance company would quote me because the roof was too old.
I went and hired a roofing contractor to give me a quote in the new roof. While he was on the roof he asked me why I wanted a new roof since my roof was perfectly fine and had another 10 years of life left in his professional opinion.
I explained about the insurance issue so he offered to write a letter that I could give them. Insurance basically told me to go to hell.
So i called roofing contractor back and he suggested that since my roof was in such good shape that I just do a metal roof over and save money. He went into the attic and inspected for any water intrusion and rotting wood and found none.
Doing this saved me about $4k over replacing the shingle roof. Ive had it now for 9 years and everything is perfect still.
You are better off ripping shingles and installing ice and water shield on bottom 3to6ft and tar paper on rest then install then installing the 1in boards but a lot of people do this
Extremely common.
The best practice? No.
If attic can be throughly inspected and no decking issues are found there shouldn't be any problems though.
Common? Yes. Correct? Not exactly.
Just because it is offered or acceptable does not mean that it should be done. For example, you would be better off going all the way down to the roof deck and fixing any structural issues while you are committing to the longevity of a metal roof. I would then put a modern-day underlayment prior to spending the significant amount of money for a metal roof. Metal roofs when done correctly will last 40+ years and the house will get the benefit of not carrying the load of shingle weight.
Yes it is. If the roof is in good condition and the osb isnt all warped then they'll go on top. Should make it even quiter. A metal roof by itself is loud during storms even with insulation.
The asphalt shingles catch any condensation from under the metal roof. BUT in the above photo - they should have run vertical straps before the horizontal so that the water has an egress.
In GA… yes
It is very common practice but not the best practice.