Roof Defect

Todays home was built in 2004, the roof covering is three tab shingles.
There were 6 - 7 shingles that had a small spot about the size of a quarter where the granuals were missing leaving the asphalt exposed. You could even see some of the fiberglass.

I’m just curious if anyone has seen this and what causes it. The shingles are fairly new. I would think these shingles are succeptible to 'breaking down" pre-maturely in the hot Florida sun.

Thanks in advance for your feedback.

roof 1.jpg

roof 3.jpg

roof 2.jpg

I have seen similar conditions caused by bird droppings, mainly pigeons.
It takes the top right off of the shingles.

I believe the damage is “Blisters” in the shingles. Read excerpts from Certainteeds, “The Life Cycle Of Your Roof” brochure, one regarding “Blisters” and a second section regarding “Granule Loss” which has a paragraph about “Open Blisters”.

There is one more possibility and this comes up only because of the nearly perfect circular area of granule loss. There may be a previous possibility that someone attempted to “Fake” hail damage on the roof shingles using various objects such as a round golf ball in a sock or using a ball peen hammer. There is good forensic technology and photos available for this through Haag Engineering.


Lots of sun in FL… if they’re blisters due (mainly) to inadequate or insufficient ventilation there should be more than 6 of them.

If they are located near each other it’s more likely a bad batch in that square…

Here is one from a couple of years ago.


You guys have got yourselves a batch of defective shingles.

Hey Matt There are many reasons for the wholes,flying golf balls if near golf course,{ive been hit by flying bolf ball} Birds are very aciddict they do and can cause the spots { as a 20 yr roofer} Ive seen some strange damage to roofs. The damage can be caused by a high nail in the sheathing,a piece of wood chip under the felt,apebble in the soul of your shoe,and maybe deffective shingles, But personally,Ithink 3tabs should be abolished. The sun in fla. is hard enough on shingles,3 tabs are to thin.Demionals are the way to go know matter were you live. Ive been in fla. 22 yrs,reroofed my house with 45 yr demionals,roof still looks great,other then weather wear.

Thanks everyone for you input and help.

The home has several shingles that were damaged and had tabs that were only secured with roofing cement. I also mentioned the shingles in above the photos and recommended that she have all of the damaged shingles re-placed.

Thanks again.


How you doing neighbor? Hope business is well and thanks for your info.