hail damage or manuf defect?

[Bruce A. King]

All opinions appreciated..........


These are really small pits or identations, probably no wider than 1/8.
Several areas of the roof had these but not all over.


Second two pictures are closeups

[mnahrgang]

Looks like common hail damage to me. (smaller diameter hail) It's common to see this on parts of a roof. usually all facing the same direction.

[Chuck Evans]

Looks like blistering to me

[Kenton H. Shepard, CMI]

It's blistering. Blisters leave a clean excavation with steep sides. Hail generally makes a shallower indentation and imbeds granules. Most blistering takes place in the first few years after installation and then stops. Typically due to poor roof ventilation and possibly a sign of low quality shingles. May cause the roof to fail slightly prematurely but functionally, since shingles are two layers thick plus underlayment it's more of a cosmetic problem than functional damage.

[David P. Valley]

I agree with Kenton.

Is there proper venting installed in this particular roof cavity? Most shingle manufacturers require ridge and soffit vents to qualify for their warranties.

[Kenton H. Shepard, CMI]

Here's a closeup shot of the same condition.

[Brian A. MacNeish]

Originally Posted by dvalley

I agree with Kenton.

Is there proper venting installed in this particular roof cavity? Most shingle manufacturers require ridge and soffit vents to qualify for their warranties.

Most shingle manufacturers require ridge and soffit vents as another out for honouring their warranty when a customer tries to get compensation.

There was a short piece in the Q&A section of The Journal of Light Construction about 15-18 years ago by Dr. Bill Rose, Researcher in roofing, ventilation, insulation at the U of Illinois. He noted some interesting results of his research that dispels much of the venting banter heard on the street......and here!!

[Peter C. Russell]

Originally Posted by dvalley

I agree with Kenton.

Is there proper venting installed in this particular roof cavity? Most shingle manufacturers require ridge and soffit vents to qualify for their warranties.

Many shingle MFG. are now offering limited warranties on non vented roof's.

IKO for one has a limited ten year warranty in their Iron Clad warranty

[David P. Valley]

Originally Posted by Brian A. MacNeish

Most shingle manufacturers require ridge and soffit vents as another out for honouring their warranty when a customer tries to get compensation.

Put yourself in their shoes....Would you warranty roofing shingles if you find blistered roofing shingles installed on a roof with gable end venting?

I wouldn't, so I'd note it in my warranty.

[Brian A. MacNeish]

Originally Posted by prussell

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Many shingle MFG. are now offering limited warranties on non vented roof's.

IKO for one has a limited ten year warranty in their Iron Clad warranty

Gee!! I wonder what the shingle manufacturers know that they don't tell the average guy. For years, roofs were unvented, then had to be vented and now back to no venting........Why would they quite abruptly change course and start offering warranties on unvented roofs?

[Kenton H. Shepard, CMI]

Originally Posted by Brian A. MacNeish

Gee!! I wonder what the shingle manufacturers know that they don't tell the average guy.

A lot. There's a lot of proprietary information that they will not discuss. They are very secretive.

Try finding specifics on the asphalt mix designs used in comp shingles.

Try to find a credible study on UV deterioration rates of comp shingle asphalt exposed by hail hits.

[ROBERT V. YOUNG]

Kenton.
Looks like installers placed a removed shingle that had been nailed before to the roof.
Also might be caused by installers and a tool,pitch fork or something else to remove the old shingles and was placed down on shingles with force.
They placed it wrong'' Shingle'' tore it off carefully and placed it on top of another shingle.
Thats my take and yes I have seen it done many times and yes I left those roofers that night.
Look at the shingle closely. Its in new shape to me and to new to have blisters and the granular is in top shape. Even in the rain notches between the teeth of the shingles, the granular is still there and lots of it..
Underneth the hole I see the selfseal is that right Kenton..

[David P. Valley]

Originally Posted by Brian A. MacNeish

Gee!! I wonder what the shingle manufacturers know that they don't tell the average guy. For years, roofs were unvented, then had to be vented and now back to no venting........Why would they quite abruptly change course and start offering warranties on unvented roofs?

Brian,

The venting requirements have changed over the years due to today's tighter homes. The older homes were not insulated to today's standards which made the older homes self ventilated due to missing or inadequate insulation. Air would flow right through the walls and ceilings and the attic would not heat up as much due to the looseness of the house.

Today's homes are insulted to an R-39 (in my area) which makes the attic cavity tight and very hot in the summer months, which in turn causes the attic cavity to become an oven, which in turn can melt asphalt shingles and cause them to blister.

As homes became tighter, shingle manufacturer's have revised their installation requirements.

[ROBERT V. YOUNG]

Kenton disregard my last statement if a big area was damaged.
In Quebec there are regulations and any building material that would degrade within the first few years or before the warranter is up would be scrutinized extremely well and taken off the market pretty fast.
I thought it might be only that one or two Pitts.
Was there a big area of that type of pitting on the roof.

[Peter C. Russell]

which in turn causes the attic cavity to become an oven, which in turn can melt asphalt shingles and cause them to blister.


Dave, can you post some recent case studies that show this to be true?