Irregular shingles

[william siegel]

These shingles are from todays inspection. This roof was put on right after Wilma in 2005. These shingles are blistering. I have two thought on this and would appreciate any other ideas. First thought - these are defective shingles from the manufacturer. Second thought - these shingles are not approved for usage in Miami Dade count (they might have been brought from up north).

Thanks for any help / ideas.

[Matt Fellman]

At first glance I'd say they are defective. It looks like for whatever reason the granuals did not adhere properly to the fiberglass base.

I suppose it could be a regional thing though too but I'd expect to find it throughout all parts of the roof. You might try emailing the pics to a local roofing contractor or supply house.

On edit - I thought I read it was isolated but I was wrong.... So, was it? Or, is it throughout all areas? If all areas I might lean away from defective a bit. Not that it couldn't still be but it would seem to increase the chance that it's the wrong type of shingle for the area.

[David Bell]

What is the exposure? Is it only in the valley as shown? Proper preperation beneath?,, Attic moisture?

[David Bell]

One more question,,attic vented properly?

[william siegel]

They are on the north side of the roof, not limited to the valleys. Attic ventilation was fine.

[Jim Luttrall]

Either defective manufacture or storage that has allowed too much moisture in the mat shingle base and/or asphalt. The moisture is boiling off and blistering the shingle surface. I'll bet it won't be long until the granules fall off.

[David Bell]

[quote=william siegel;114527]These shingles are from todays inspection. This roof was put on right after Wilma in 2005.


Any chance these shingles were under water during the storm?

[william siegel]

[quote=william siegel;114527]These shingles are from todays inspection. This roof was put on right after Wilma in 2005.


Any chance these shingles were under water during the storm?

Don't know, but I doubt it.

[Michael Carson]

I'll take defective shingle, poor storage for 200 Vanna :p

[Matt Fellman]

the mat shingle base and/or asphalt.

Not trying to split hairs but... aren't modern day shingles all fiberglass backed? I seem to remember the Owens Corning guy in a CE class saying ashphalt has been phased out..... regional thing maybe? Or, maybe I was just half asleep? :)

[H.G. Watson, Sr.]

I'll take premature aging & blistering shingles for $400 Alex....What is (may be actually) improper handling (allowing moist or wet conditions), not storing properly, and/or installing less than fully dried, moist or wet shingle bundles.

[Jerry Peck]

I'll take premature aging & blistering shingles for $400 Alex....What is (may be actually) improper handling (allowing moist or wet conditions), not storing properly, and/or installing less than fully dried, moist or wet shingle bundles.

I'll take moisture for $800 ... either in the shingles as stated above or installing them on wet underlayment ... and I'd like to buy insurance for $200 in case it is a manufacturing defect. :D

[David Bell]

Maybe it's a 15 year shingle going thru those awkward years of blemishes.

[Jim Luttrall]

Not trying to split hairs but... aren't modern day shingles all fiberglass backed? I seem to remember the Owens Corning guy in a CE class saying ashphalt has been phased out..... regional thing maybe? Or, maybe I was just half asleep? :)

Fiberglass mat as opposed to organic (paper/felt) mat but all composition shingles use asphalt (petroleum product) to coat the mat, bind the granules, and make it water proof.
If you have to much moisture in either component then you have a defective shingle.
From what I remember from a GAF plant tour, they "cook" their own asphalt and apply it to the fiberglass mat under strict standards to prevent too much moisture from causing those blisters and other problems.

I do think there are some organic mat shingles still made (up north I think) in some regions of the country.

[H.G. Watson, Sr.]

Not trying to split hairs but... aren't modern day shingles all fiberglass backed? I seem to remember the Owens Corning guy in a CE class saying ashphalt has been phased out..... regional thing maybe? Or, maybe I was just half asleep? :)

ASHI Reporter, May 2002, John Cranor, Inspecting Today's Predominant Residential Installed Roofing Material: Asphalt Composition Shingles, First paragraph:



I find myself inspecting asphalt composition shingles more often than any other installed roofing material. During the past 25 years as this type of shingle gained in popularity, the most frequently used type changed from a primarily organic (cellulose) reinforced, Class C fire-rated shingle to an inorganic (fiberglass) reinforced, Class A fire-rated shingle. Flexibility is one of the differences between the two. Fiberglass or inorganic shingles are brittle and easily damaged in cold weather. If organic shingles are still used, it's probably because they are more flexible than fiberglass in colder weather. Even though the make-up has changed, the term “asphalt composition” is used to identify both organic and fiberglass shingles.


Further down in the article under the subheading "What happens as shingles age" that paragraph concludes with:


Blisters may appear as shingles age. The blisters may be as small as peas or slightly larger – open or closed. I call open blisters “pits.” Blisters often are caused by improper attic ventilation, although some roofers believe they are due to a manufacturer’s defect. I’ve seen blisters on three-year-old shingles.

But WS says the ventillation was correct.

Another thought on moisture - no drip edge or installed incorrectly and wind driven rain moisture being trapped then the sun does its buisness.

Its a good basic article, might be worth a refresher skim. Here is a link: Inspecting Today's Predominant Residential Installed Roofing Material: Asphalt Composition Shingles | ASHI Reporter (http://www.ashireporter.org/articles/articles.aspx?id=845)

[H.G. Watson, Sr.]

Didn't mean to echo you Jim Luttrall, I was typing for a quarter hour! When I started I hadn't refreshed the page first and didn't know you posted on the question raised already.:o

[Matt Fellman]

Thanks for the info Jim, HG and others... The link in HG's post is a great read. It's the best 10 minutes I've ever spent learning about roof installs and I've been doing this for over 10 years. Most of it I knew but there is some I didn't.

I've seen the pitting question go around here before and hail damage has been brought up but wasn't mentioned in the article. The author seems to really point to attic ventilation which is interesting.

The blistering in the OP is somewhat explained... or least a possible cause. To me, these comp. shingles can and do degrade at greatly different rates under different conditions.

After years of looking at them I'm often spooked at how close I can come to the exact age just from a first glace. Something not mentioned that is a very valuable tool is pulling dates off of plumbing vent flashings (usually stamped as mm/dd/yy near the bottom right of the metal) or off the plastic square roof vents (usually a circle with the two digit year inside and an arrow pointing at the month - it's setup like a clock).

[H.G. Watson, Sr.]

Matt Fellman,

The article was part of a series. Here is Part 2 (June 2002 ASHI Reporter), Damages such as Hail are discussed. I'm glad you found Part 1 to be a nice review, I think you'll find part 2 similarly addressed (the link may look the same but is to part 2 on the next issue):

Inspecting Today's Predominant Residential Installed Roofing Material: Asphalt Composition Shingles | ASHI Reporter (http://www.ashireporter.org/articles/articles.aspx?id=808)

[Jake Guerrero]

From what I remember from a GAF plant tour

Jim, here I was thinking you had fallen asleep in that class :)

[Jim Luttrall]

Jim, here I was thinking you had fallen asleep in that class :)
I did the first time but I took in again:p