hail damage or manuf defect?

Where did I state that I tell my clients about roofing manufacturer warranties. Re-read my posts…

I don’t care how many shingles you laid… from my experience, asphalt shingles absolutely melt (curl, cup) from improper ventilation. I’ve never seen asphalt shingles hold up more than ten years to a fully insulated attic with no venting. They simply cup and become brittle due to the attic cavity becoming somewhat of an oven.

This is one of many images that I have that prove my point…

This is a twelve year old roof with no ventilation…


Tell me what caused this roof to deteriorated at an early age?

So do you agree that by ventilating a roof it decreases the attic temperature thus extending the life of the shingle?

My mistake on the comment about warranties in reports sorry.

PS. do you have the same picture of that house from different angle’s?.. from the ground?

If that is a 12 year old roof why is there a cast iron vent stack coming through the roof with no flashing, how would that pass code and who uses cast iron anymore

I never stated it was a 12 year old home. Here you go again…

It’s a re-roof. Have you ever replaced defective roofing shingles? I never laid a shingle in my life, but I’ve inspected many roofing materials with improper venting, improper flashing, improper drip edges, improper weaving, and the list goes on and on and I’ve got images of them all.

Well good for you Dave, glad your an expert. Would you say the shingle’s failed on that roof solely due to the lack of ventilation or solar heat gain or a combination of both.

Both…

You might want to read the article I posted the link to. It has some very good information and case studies pertaining to vented/non-vented roofs.

Effect on Shingle Life

In general, shingles installed on unvented attic assemblies operate at a slightly higher temperature. This has impacts on the durability of roof assemblies. A 2 or 3 degree F. rise in average temperature is typical for asphalt shingles and a corresponding 10 degree F. rise in average temperature for sheathing (Parker & Sherwin, 1998; Rudd & Lstiburek, 1998; TenWode & Rose, 1999)
All other things being equal, applying the Arrhenius equation (Cash et.al, 2005), a 10 percent reduction in useful service life should be expected. This is comparable to the effect of the installation of radiant barriers. What is more significant to note is that the color of shingles and roof orientation have a more profound effect on the durability of shingles than the choice of venting or not venting (*Rose, 1991](http://www.buildingscience.com/documents/digests/bsd-102-understanding-attic-ventilation/bsd-102-understanding-attic-ventilation/bsd-102-understanding-attic-ventilation/bsd-102-understanding-attic-ventilation/bsd-102-understanding-attic-ventilation/f/bsd-102-understanding-attic-ventilation/?full_view=1#Rose_1991)) – double or triple the effect of venting/non venting.*

Dave, I’m not challenging you, just trying to have a two sided discussion.

Have a great day.

David is right in his statement.
I have seen this even in a climate as Montreal Quebec.
A cold climate. I think zone 3 if I am not mistaken.
I have seen melted elements of shingles often and also seen roofs that have not lasted 10 years.
In Quebec it is Illegal to sell shingles with 10 year grantee they must be 15 plus.
I have seen melted gum strip ( self seal ) part of the shingle.
I have also noticed the weakest viscosity of the shingle run It looks like tar or even oil dripping down a shingle.
I will not put words in his mouth but will try to clarifie his statement by saying that the shingle was not melting but parts of the system ( elements of ) the shingle melt and show sings of dripping running, etc.
There for the shingle is dry , curled up or down , self-seal broken, dried up leaving weather possibly enter the decking and into the attic and thusly the home.
The roof must be replaced before its time…

David -tread lightly for there are some here that will excite you with your statements.
Its a great learning tool and all challenges are to be taken with a calm head and professional degree understanding.
For what ever the reason someone challenges you ,take it with great pride that your statement and observation is being addressed.
>You have the chance to gain knowledge by doing back studies and presenting your observations by many of InterNACHI’S finest.
>You also have a chance to address the issue in a NONLEGAL FORUM instead of the real thing ( a court of law }.
>Please take it as a blessing and excuse there added words for when you are right OTHERS WILL TAKE NOTICE,and you have great satisfaction in learning your craft.

Good for you and keep at it.

How does anyone know for sure if this roof is 12 years of age? I have come across several roofs that have documentation, but are actually older. One home I did a few months ago was stated to be only 5 years of age, but that was because the current owner lived there only 4 years, and was told by the former owner that the roof was new. That roof was so bad that leaks were noted, and, a few days later, the buyer’s insurance company would not insure it due to the poor condition.

Some surface pitting is almost normal. Kenton is correct. There are many different roof formulations, and some that do well in the north, may not do well in the south.

Nick, we may need to start a roof thread section.

Good point Gary.
Roof thread.
Nick has already blessed us with master roof inspection series.
A roof thread would be great and also address the problem of ladder safety.

Robert, as I said in my earlier post my intention was not to challenge Dave but to point out that many experts in the field of building science have concluded that the lack of ventilation is only part of the problem with shingle degradation and many instances a small part. I was just trying to start a conversation about this topic and unfortunately I think Dave got a little sensitive about it. To bad because that was not my intent and I’m sorry you see it that way.

Take a look at the information I posted. Studies have shown that ventilation or the lack of it only decreases the shingle temperature by 2-3 degrees and the roof deck by maybe 10. And, as I said I’m not saying it’s not going to contribute but it’s just part of it.

More shingles are damaged by color, number of layers and orientation of the roof than by lack of ventilation. Just trying to open the discussion to other possibilities and hopefully we all learn from it.

Read this study done for the NRCA:

http://www.professionalroofing.net/archives/past/mar02/feature2.asp

More on roof venting from Fine Homebuilding:

Martin Halladay used to be the the editor of “Energy Design Update”, a pricey periodical (US $385/year) that keeps you ahead of the curve. It is not as good technically as it used to be when it cost me 550 Canadian.....remember when: .70US = $1CDN.

A few years back, Martin, myself and a few others had a fight on against the P2000 insulation company in a huge scam in which the company should have been prosecuted for fraudulent claims…1" of regular expanded foam insulation with foil on one side was claimed to be R27!!! Wisconsin, by law, limited their claims to R5…I’d like to shake someone’s hand there.

Mr.Russell
Thank you for your reply Mr.Russell and I do know you had no intent upon being harsh or judgemental.
I see you share you knowadge freely and open and was trying to matbe aid david in his findings.
You possess the wording and skill to addres the subject at had with documentation and thats a plus.
Please excause my spelling.

As shingle manufacturers catch up and truly understand the physical phenomena they are seeing, they’re realizing some of their past understanding of the facts was off base.

Brian, good info. in all your post’s. I think the problem is shingle MFG. have hammered home the statement… No ventilation no warranty and most people today still believe it. It’s to bad because as a contractor I started reading studies as far back as the mid 90s and through all my continuing education have found there is a ton of info. about the subject.

Earlier this year I was hired as an expert witness in a 250K remodeling job and testified in court about not only the poor construction but problems associated with the HVAC system in the attic and outside the thermal boundary.

By using my blower door, thermal imaging, and several article’s as my evidence I was able to prove that not only the HVAC system was the main culprit but the ventilation should be completely eliminated, the insulation removed from the floor and spray foam (closed cell) be added to the roof deck. This would bring the HVAC system within thermal boundary and eliminate much of the heat loss.

As you can imagine, the expert witness for the contractor tried to discredit me and one of his claims was that if my recommendations where followed the shingle MFG. would not warranty the shingle’s. Unfortunately for him I had done my homework prior. I identified the shingle MFG., contacted the New England REP., who I have worked with before, and obtained the proper warranty documentation that clearly states that they will warranty a non vented roof for a period of ten years. Guess who won?

The point of all this is to stay informed, listen to other people’s idea’s or knowledge and do the best professional job we can no matter who are clients are. As a contractor I know the rules on building materials and codes change so quickly it’s hard to keep up. As a home inspector this is even more difficult. Fortunately there is plenty of information and case studies out there.

Yes Brian I have fought with rep,s and they always came at the job-site closed minded.
That was many years ago.refreshing to see there is change.
They were versed in theory and not one of them had any pratical experance nor did they hire any retired roofer to help turn theroy in pratical use and understanding.
They where book trained.

Peter, the manufacturers I’ve talked to required a ventilation space on the under side of the roof deck for the manufacturer’s warranty to remain valid. Can you post a link showing to a site showing that that’s not true?