I have not seen this before.
Why is this roof installed this way?
Is this an acceptable method?
Looks like decorative to me
Could you explain what you mean.
It is not a decorative shingle.
Seams like an improper installation.
IMO, decorative “touch”
Single manufacturer will use it to wiggle out of any warranty issues should they occur. As long as this roof is properly nailed and all tabs are securely sealed down (Most likely some would have been done by hand) I would accept it (make sure to check the shingles at the thick overlap lines).
Theory question.
Could not the bending in the material caused by the overlap lead to premature failure ?
Bob I believe the dbl layer will cause a dip similar to when the starter course isn’t cut down from a full shingle. I did not notice that in the pictures. But I would say you are correct.
Yeah I mean they are nailed down then forced up at maybe a angle not intended.
Correct me if wrong after all I just glanced and have not had time to think on it yet.
Depends on nailing patter I suppose and unlike many here never was a roofer.
Dave, did you ask the Seller?
There are 3 layers at the profile steps.
Why every 8 courses?
40" doesn’t relate to anything.
Curious myself, never seen anything like it. 
[quote=“dmacy, post:3, topic:54467”]
Could you explain what you mean.
It is not a decorative shingle.
Seams like an improper installation./quot
no its not a decorative shingle. some people install 20 yr comp this way for the LOOK…ie decorative…See it every now and then…in my 16+ years in roofing I never have installed a 20 yr this way. It not that big of a deal…
how could you see the starter row with out taking up the first row of shingles??? on a older 20 yr like this you would have used a full 20 yr shingle and turned it around for a starter row…imo some of you guys need to brush up on your roofing…just my 2 cetns
And when you turn it around instead of cutting it in half, you do not get the seal tabs to hold down the first course of the three tab and they blow off the roof on the first wind. 
No need for insulting fellow members to make yourself look important till you learn how to spell.
Please convey information that helps by all means but this is not the political section and should not carry over.
Many members do not post out of fear that someone will belittle everything they say here Brian.
I will remove this particular post in a little bit (OK)Thanks:)
Applying shingles in a pattern is tricky.
It has to be laid out in a fashion as to enable its wind-shear ability( so you get no blown out shingles) along the the ability to shed water in a positive manner ( the slope is positive ) and not lesser than that of the roof its being applied to.
Reduce the slope and you get ice damming in the winter.
Many factors.
I will try to post some photo,s of aesthetic roofing patterns.
I frequent a small town and the brick and roof patterns are amassing.
This one I have never seen but I have seen a variation of and hesitate to give this one the thumbs up for proper workmanship.
Look at the chase and stacks.
For me not well done.( flashed )
Vacant house, no seller to ask.
Here is a pic of the garage.
Been patched, little mossy.
There is the 8 strip panel again and 6 for starters.
Must be someone’s idea of an asthetic design I have never seen or heard of before.
Since there are 3 layers, it would tell me they did it on purpose to give it that profile.
Although this roofing is showing some age from the spacing of the tabs and granule loss, I don’t see how this installation would impair the functionality of its pupose. The Manufacturer may disagree, but they will find many things to deter from paying or replacing on a warranty.
Interesting find David.
Let me know should you find anything to that regard.
[quote=“bsmith2, post:9, topic:54467”]
I disagree,
It is not proper workmanship.
Plan and simple.
Blow up the photo.
Now look at the ( started strip ) used to elevate the shingle and give a 3d dimension.
Look and see a void, look the the rain notch at the top shingle and the strip below it.
It does not even meet.
The rain notch shows a void or whole, and the shingle bellow should be carried up and under the top shingle at least 3 inches for a patten to be safe.
The strip ( partial shingle being used as dimensional Aesthetic) should be carried up at least 3 inches up and under the upper shingle for weather purposes.
Plus to not be such an aggressive angle.
Look how the shingles have created a seam, ridge, and how were they set.
Nailed at the gum strip?
you cannot. it would affect the tab above.nor enought clearance.
I have done dimensional at least 30 years ago.
Not many and with an old roofer that is 80 pus this year.
Carried his own shingles till he was 65 plus.
You are the first one here Marcel to agree with me that the manufacture will do almost anything to void a warranted roof and there product.( residential ) commercial is an other story because the rep is on the job most of the time taking photos…
HA HA HA.
I fought with others.
They were certinly not roofers.
HA HA HA
say what??? most 20 yr has a very small seal strip on the back of the shingle in the middle of the shingle that is why most guys use the hole shingle…when you cut a 20 yr in half its now to short and the nails of the first row of shingles will miss the starter row…ect…this is old school way of rofoing…now days you buy a strip starter that comes in a bundle ect…
Mr.Smith.
Mr.Cyr is making points that roofers in his area use half starters.
It is easy to take the ( cut portion ) and seat-it on-top of the area left open using’’ half shingle for starter’’ method.
This ‘’ SAY WHAT’’???
Using the wording ‘’ say what ‘’ implies you are being presumptuous, and arrogant + rude.
Treat members here with the respect they DESERVE please.
Others will do so to you.
Be patient. Have an open mind or you will fail.
As I stated before please, Mr.Smith we are all certified residential building inspectors here.
Respect all the opinions and answers you hear please.
I went to your website.
Bravo, the first one thinking outside the box.
Your roof inspection being predominant and displayed in the opening of your website. ‘‘Bravo’’
Thinking outside the box and looking to every available angle you can cover.
JJ laughed at me for thinking I was doing roof inspections.
HA HA HA HA.
Good on you mate.:D:D:D
Just a point of view form someone with ‘‘new eyes’’.