Comp shingles on 2:12 to less than 4:12 pitch.

Who else wonders how "double coverage", a term historically referring to double-coverage of comp shingles on 2:12 - less than 4:12 pitches, somehow morphed into meaning double coverage of underlayment - To the extent the UBC, then IBC/IRC adopted?

Atlas has an 1.5 inches on their lamination and I have been using ever since they went that way, I love that fact. With our recent 30 inches of rain in 50 hours event, ive had a few that water travelled from the butt joint to the closest fasteners and leaked I found it to be due to aggressive sealing of the shingle also. The duration has a deflection in their nail line that will cause water to travel to the fasteners wouldn't use them under a 6/12 pitch. if you run your finger across it you will feel it, it is a water diverter guaranteed

That was an interesting article on the radiant energy. A good day is when you learn something new that gets your mind working. I'm considering doing an exterior refit on my house and was looking at the radiant insulation but after reading the reviews about the product I don't know if it's worth the money.

Do they make a radiant vest to keep you cool in the summer and warm in the winter. Maybe that's what those ETs wear. 😀

I'm kind of in the same boat there, but I increase the setbacks and use stainless nails and even on laminates have had no problems with any of the underlayments, either synthetic or rag felt. My biggest issue is with composted leaf debris. Much as I like it, rag felt rots.

anything less than 3 I recommend 3 tab with double layer 15# felt. Someone mentioned malarkey and I have and I had been tempted to use them since they have a tapered edge. That confirms what I was thinking so may start giving those a shot for customers who still want dimensional on lower slopes. Also, don't know what it's like in your area, but most companies are using synthetic felt now and some brands stat right on them that they are not to be used in less than 4/12 pith. I must be the only one in my area that double laps traditional felt and stays away from synthetic in those applications.

I'm not what you call a scientific type of guy either but I pay attention as well as I am able as often as I am able. I've got a scientist daughter who sometimes gets annoyed with my tactile-based sensibilities but she has never given up on me entirely cuz I do try. lol.

I ran across this explanation recently which I found helpful and hope is accurate.

http://www.radiantbarrier.com/physics-of-foil.htm

I believe the sunburn/snowburn is caused by UV (related but different and far nastier)

The problem for us unscientific types is we can't actually see infra-red, ultra-violet, radio, or any other type of electro-magnetic energy. Microwaves aren't hot but they get things hot. While we're out there pounding nails a lot of other folk are making a living off of this stuff. I would say it behooves us to stay, or try to stay, within sight of what they discover. It certainly does affect us and with the newer building standards and building science, it impacts our reputations big-time if we ignore it all.

So.....Does all radiant energy get absorbed somewhere once it enters the earth's atmosphere? I'm not a scientific type of guy but sometimes things like this intrigue me. If you say that the radiant energy reflected keeps going somewhere to find a place to land, would that place be my shady side facing the roof surface? Something akin to getting a sunburn off of reflected snow when skiing or out on the water when fishing. I've been barbecued a few times out on the boat even though I've been in the shade of the canopy all day.

I remember asking about red roofs reflecting more radiant energy than any other colour a few years back. I also found red shingles tended to last longer than other colours.

seen-it-all:

Not like the radiated heat you feel when you hold up a space blanket next to your face. I'll have to pay better attention next time. Has to be something though.

What I'm thinking...conductive heat is what burns your butt when you sit down on red-hot shingles and convective heat is what you see when you put your head down next to the roof and look down the line at the heat waves coming off the surface. Both of those heat types are the result of heat gain in the comp looking for a way out and neither of those are nearly as radical as for other, regular comp. You also don't get bundles heating up under the topmost bundle in a stack and you don't have to peel them apart because they don't get nearly as limp and sticky.

I'm sure the radiant energy that isn't reflected causes the heat gain there is, but the radiant energy that is reflected never shows up as heat because it only turns to heat when it "lands." Travelling through space it has no heat. The radiant comp just sends it off down the road to strike something else.

Pablo is also my favourite go to shingle over the years. More so the past few years as they are packaged 4 to a square and are easier to handle in my old age :) I believe they have kept the same colour blend for the past 25 years where as other manufacturers seem to change theirs up every 5 years or so. They also are very accommodating with warranty claims. Had dealt with a few of their late 80's HO25 cracking issues and the homeowners received full material credit. Goes a long way in my books when a company takes ownership for a mistake without putting up a fight.

egg: I was looking at the specs on the Pabco Radiance and they say they reflect 28% of solar rays. Question: Do you feel any of that heat being reflected back on you when installing them?

The kicker is that whatever shingle we love to install and give the best performance, it is always up to the customer and how much they want to spend. The tragedy is that with so many choices all it leads to is confusion.

Dragon's teeth, yeah. Never really liked that inward-taper look but I have to say Pabco makes a tough shingle which has proven itself to be a long-lasting beast and I find myself using them more and more. In fact, their Radiant Elite has now ascended to the position of my shingle of choice. I believe that material is poised to last virtually forever when installed in all but the most merciless locations. You can work them on even the very hottest days. When you take out that much infra-red, I'll bet you get another ten years. jmho/fwiw

Love the CT Solaris Gold series as well. Not sure who was responsible for packaging them three to a square though. That's downright heartless.

natty Said: THE ZONE was invented to compensate for poor roofing practices. It is much like the Owens-Corning sure nail technology which is pure crap in my opinion.

That's my only problem with the Zone haha. I'm conflicted because I complain about how the jacklegs are costing consumers thousands(individually) but then I benefit from it by having a never ending supply of repairs and 10 year old re-roofs. I do think it's a good thing though.

Not sure how I feel about OC's strip. High nailing is a problem, but the blowing through is worse in my eyes. The high nails eventually break through, especially if they are just barely high. With OC's strip, at least it's reinforced so the nail shouldn't be able to go completely through.

Me and my Dad have argued about this many times. He is in the "pure crap" camp. I don't mean to defend not nailing the low part, but I'm just speculating that it's infinitely better than standard 3/4" line.

Malarkey's are the best shingle to install. Consistently square cut, come out of the wrapper easily, and naturally a larger nail zone.

twill59 Said: R U saying that the Malarkey is angled in like the old Celotex, as opposed to flaring out like all others except the straight IKO Cambridge?

That would be the dragon teeth. No, I am talking about the nail area. Malarkey has a 2" nail area patented as THE ZONE and the bottom layer is tapered. When exposed at 5", there is no hump. Most laminates have only a 3/4" nail line which most slap-on roofers can not hit.

THE ZONE was invented to compensate for poor roofing practices. It is much like the Owens-Corning "sure nail technology" which is pure crap in my opinion.

wywoody Said: On any product that has thick butts like shakes or tile, shortening the exposure can actually lesson the surface pitch enough that it does more harm than good.

I live in an area where there are hundreds of 2 1/2 pitched roofs. Most have gone to the laminate shingle but are still slapped on without a care. Hence, most leak and they get reroofed in less than 10 years. No one seems to learn.

If I go to the laminate, I only use Malarkey, reduced to a 5" exposure, because its laminate lap is 2" and tapered. It makes all the difference. I can adjust the nail line and always hit solid wood. And the tapered edge won't make a hump to hold water like the other laminates.

egg Said: When it comes to underlayment I agree with those that say water ought not to be getting there in the first place, but I put it on anyway, and I have seen the benefits over time of using it. There was a year when one major manufacturer provided letters stating that its use was entirely optional, although they rescinded that in pretty short order.

I read somewhere and have experienced the fact that fiberglass shingles are not impervious to moisture; therefore, that underlayment is crucial in keeping the deck dry. And, a properly driven nail will cause the underlayment to act as a gasket at that vulnerable location. I have seen nails that did not hit solid decking, over time, cause a hole to form and leak.

It's to eliminate the two-inch lap vulnerability at all of the horizontal seams.