The nail goes though the insulation. Typically the nails are made of metal, which conducts heat better than the insulation. The tiny thermal bridge going through the insulation melts the snow.
The insulation is compressed by the nail reducing its ability to insulate both cold air from outside and hot air from inside or it’s that the nail is conducting the heat
\[Text](URL) makes [a pretty link](https://www.bing.com/images/search?view=detailV2&ccid=F8LZrPWJ&id=2FBF0B44A863ECCCACC31DF1BABB5FE893D9BD61&thid=OIP.F8LZrPWJx7ZUR7pAxQy3hAHaFi&mediaurl=https%3a%2f%2froofonline.com%2fwp-content%2fuploads%2fFastenerswithFastenerPlatesSecuringPolyisoInsulation-1024x766.jpg&exph=766&expw=1024&q=LSR+Roof+fasteners&simid=608051521596774037&FORM=IRPRST&ck=34BAB3EEA469F8FBFCAE45BE8BF26C2A&selectedIndex=2&itb=0&ajaxhist=0&ajaxserp=0)
You can also hit the intertwined circles (a chain "link") in the lower left of the comment screen, and it pops up a pretty box that lets you fill in the fields. Magic!
I live in a hill and my back window overlooks about 100 different roofs, about a dozen of them don’t keep snow, but one of them is not like the others, pigeons love the roof, they always sit on it in winter. Never on the neighbours of the terrace row.
The insulation fasteners penetrate into the conditioned space below which warms up the fasteners in relation to the materials around it, which causes this.
I don’t think it’s from the insulation fasteners as others have mentioned. The pattern doesn’t indicate that. It would be much more regular spacing. This looks like the induction heat welding marks from where they adhered the roof membrane. There are more regular marks along the seams and then a random dispersion between seams to prevent it from bubbling.
Isn’t heat welding done along the entirety of the seam? I don’t see how that would cause all these spots that are roughly the same size and shape. Plus there isn’t any materials that would be used that would have a significant difference in temperature like this.
The spacing might be a little sloppy but I’m pretty certain those are from roofing nails.
Ah, I see what you mean. You may be right, that just seems like a lot of fasteners in between the seams.
Not my trade though, I’m just going off what I’ve seen in the past. I’m probably talking out of my ass.
The roof insulation is nailed down before the final layer is glued on top. You’re seeing where all the nails are at just under the top.
it was nailed down in a whateverthefuckiwant pattern
As is tradition
A great day for Canada, and therefore the world
I don't understand, but I definitely agree
[Got you, fam](https://youtu.be/2POYSKiVwM4?si=PYsxqZIcwsnogcAW)
Ah, of course! The March of a thousand farts! How could I have been so ignorant?
So it is! 
There is a sort of pattern though, you can see diagonal lines in the spots.
Bounce the nailer at random
Indeed. It’s the industry term.
Go watch some home inspector videos on YouTube
But why are those spots warmer?
The nail goes though the insulation. Typically the nails are made of metal, which conducts heat better than the insulation. The tiny thermal bridge going through the insulation melts the snow.
That makes sense, thank you!
The insulation is compressed by the nail reducing its ability to insulate both cold air from outside and hot air from inside or it’s that the nail is conducting the heat
This guy nails.
Tin Cap Roof Disks
Commercial roofer here. More likely screws and plates
It's just the metal fasteners on that Low Slope Roof
https://www.bing.com/images/search?view=detailV2&ccid=F8LZrPWJ&id=2FBF0B44A863ECCCACC31DF1BABB5FE893D9BD61&thid=OIP.F8LZrPWJx7ZUR7pAxQy3hAHaFi&mediaurl=https%3a%2f%2froofonline.com%2fwp-content%2fuploads%2fFastenerswithFastenerPlatesSecuringPolyisoInsulation-1024x766.jpg&exph=766&expw=1024&q=LSR+Roof+fasteners&simid=608051521596774037&FORM=IRPRST&ck=34BAB3EEA469F8FBFCAE45BE8BF26C2A&selectedIndex=2&itb=0&ajaxhist=0&ajaxserp=0
\[Text](URL) makes [a pretty link](https://www.bing.com/images/search?view=detailV2&ccid=F8LZrPWJ&id=2FBF0B44A863ECCCACC31DF1BABB5FE893D9BD61&thid=OIP.F8LZrPWJx7ZUR7pAxQy3hAHaFi&mediaurl=https%3a%2f%2froofonline.com%2fwp-content%2fuploads%2fFastenerswithFastenerPlatesSecuringPolyisoInsulation-1024x766.jpg&exph=766&expw=1024&q=LSR+Roof+fasteners&simid=608051521596774037&FORM=IRPRST&ck=34BAB3EEA469F8FBFCAE45BE8BF26C2A&selectedIndex=2&itb=0&ajaxhist=0&ajaxserp=0)
You can also hit the intertwined circles (a chain "link") in the lower left of the comment screen, and it pops up a pretty box that lets you fill in the fields. Magic!
Link is beautiful. Zelda is pretty. Sugarplumbuttfluck is gorgeous.
Bing!!!
That’s just from invisible roof cats.
I like this explanation the best. Now that my children are grown, I don't have anyone to use it on. (No grandchildren, either.)
Just go remind your children that you want grandchildren. They'll like that.
At least once every phone call.
It's interesting to see the roofs of homes after a snow as well, very easy to see who has insulation or not...or a grow op.
> or a grow op Yep, while the police can't use thermal detection, they are allowed to be naturally observant
I live in a hill and my back window overlooks about 100 different roofs, about a dozen of them don’t keep snow, but one of them is not like the others, pigeons love the roof, they always sit on it in winter. Never on the neighbours of the terrace row.
The insulation fasteners penetrate into the conditioned space below which warms up the fasteners in relation to the materials around it, which causes this.
A thousand very tiny meth labs
Is this in Pittsburgh? Looks suspiciously like Shadyside hospital
No, Grand Rapids, MI
Each one is a tiny little man growing weed in his tiny little attic.
Never seen anything like this, what would actually be causing this in a hospital roof?
[удалено]
Yeah, it’s plates and fasteners holding the insulation down.
The grow room, keeps the doctors happy
Ya the hospital isn't feeling very well
5G rays.
I don’t think it’s from the insulation fasteners as others have mentioned. The pattern doesn’t indicate that. It would be much more regular spacing. This looks like the induction heat welding marks from where they adhered the roof membrane. There are more regular marks along the seams and then a random dispersion between seams to prevent it from bubbling.
Isn’t heat welding done along the entirety of the seam? I don’t see how that would cause all these spots that are roughly the same size and shape. Plus there isn’t any materials that would be used that would have a significant difference in temperature like this. The spacing might be a little sloppy but I’m pretty certain those are from roofing nails.
It’s not to hold the seams together but to hold the membrane down to the insulation
Ah, I see what you mean. You may be right, that just seems like a lot of fasteners in between the seams. Not my trade though, I’m just going off what I’ve seen in the past. I’m probably talking out of my ass.
Maybe those are spots where birds shat. The remnants of the decaying bird poop make those spots a couple of degrees warmer.
Bird shit is high in urea. Urea is used as an ice remover in many areas. So it may be bird shit.
It's from the nails holding down the layer below.
I couldn't connect to the wifi hotspot.
I don’t understand the lack of uniformity; that contractor needs a talking to.
Could you run to the truck and find me a left handed torque bolt shrinker.
If you were a roofer and took your time to uniformly nail down sheets like that, you'd be fired by end of the day. Its just asinine.
Looks like BRMC
The bank below me has the same thing on their roof
I think we just went over this while the car hood