Pitting Shingles

[Jon mackay]

I came across this roof yesterday and the shingles had these unusual worn areas all over. They were little pit marks that covered the entire roof in various areas. It was a bit odd and I thought that perhaps someone might have an explanation. The roof was a single layer and the attic appeared to be vented well.
I thought that it may have been a defective shingle batch??

[John Arnold]

Hail?

[Jon mackay]

I suppose it could have been but I don't want to speculate.

[Jerry Peck]

Looks to me like what you would see after these broke off: http://www.inspectionnews.net/home_inspection/roofing-system-home-inspection-commercial-inspection/13435-tiny-roofing-blisters.html

[John Kogel]

Hail damage can be simulated by hitting the roof with a ball peen hammer. Those holes are not likely from hail. Falling icicles maybe. :) Popped blisters is a better guess.

Goofs in golf shoes is another. :eek:

[John Kogel]

The little pin holes in this roof were made by Goofs in Golf Shoes.:)

[Michael Schirmer]

I've always called this as possible over-heating. That's what it usually look likes when shingles are ultimately boiling. Of course if the pattern is that same Nike hash-mark all over then I'd go with the golf shoes. Recommend further review by a qualified greens keeper to replace all divots to avoid further damage.;)

[Gary Wilson]

I would vote in favor of popped blisters. Doesn't look like impact (hail) damage. Usually with hail you get areas of granule loss, but rarely holes like your pic shows..

[James Harlow]

Blistering is a result of moisture trapped in the shingle either during the manufacturing process, due to poor ventilation, installation over a wet substrate and a breakdown in mat layers. The blisters pop outward and you would see a cup shaped area with missing granules. When blistered shingles break open they can leave shingles susceptible to damage such as granule loss, color fading and may even lead to water leakage and should be replaced. While blistering shingles are rarely visible from the ground, a punctured blistered shingle will be easily spotted because it will likely appear to have black spots - which are actually the exposed asphalt shingle. You will want to advise clients to contact the manufacturer (if known) of the roof shingles that are blistering as this may fall under the manufactures warranty. Usually they will prorate replacement of material depending on the age of the roof, but won't include installation labor in settlement amounts.

Hail damage produces a bruised surface area with dimples similar to that made by a ball peen hammer strike. Areas of lost mineral granules will be apparent, with more severe granule loss on roof slopes facing the direction from which the hailstones fell (or blew) during the storm. Inspecting an asphalt shingle roof shortly after a hail storm, if the roof has been damaged, should show that the areas of mineral granule loss have exposed "fresh" looking shingle substrate - the asphalt impregnated shingle substrate will not yet have been weathered by sun exposure. You will usually see other areas of damage with hail such as dented aluminum roof vents, aluminum wrapped trim and even sometimes trim paint loss especially on wood window sills. I ask if I suspect hail damage as the seller may have already collected settlement from insurance company for hail damages and chose not to replace roof.

[branden wilson]

Blistering is a result of moisture trapped in the shingle either during the manufacturing process, due to poor ventilation, installation over a wet substrate and a breakdown in mat layers. The blisters pop outward and you would see a cup shaped area with missing granules. When blistered shingles break open they can leave shingles susceptible to damage such as granule loss, color fading and may even lead to water leakage and should be replaced. While blistering shingles are rarely visible from the ground, a punctured blistered shingle will be easily spotted because it will likely appear to have black spots - which are actually the exposed asphalt shingle. You will want to advise clients to contact the manufacturer (if known) of the roof shingles that are blistering as this may fall under the manufactures warranty. Usually they will prorate replacement of material depending on the age of the roof, but won't include installation labor in settlement amounts.



Hail damage produces a bruised surface area with dimples similar to that made by a ball peen hammer strike. Areas of lost mineral granules will be apparent, with more severe granule loss on roof slopes facing the direction from which the hailstones fell (or blew) during the storm. Inspecting an asphalt shingle roof shortly after a hail storm, if the roof has been damaged, should show that the areas of mineral granule loss have exposed "fresh" looking shingle substrate - the asphalt impregnated shingle substrate will not yet have been weathered by sun exposure. You will usually see other areas of damage with hail such as dented aluminum roof vents, aluminum wrapped trim and even sometimes trim paint loss especially on wood window sills. I ask if I suspect hail damage as the seller may have already collected settlement from insurance company for hail damages and chose not to replace roof.


wow, it looks like someone here is qualified to be inspecting roofs! big respect james, i hope it rubbs off on some of the others!

inspectors who know what they are talking about are actually helping people and the industry, but the vast majority are just perpetuating silly lies. good job james, us real tradesmen thank you.

[Daniel Leung]

The roof was a single layer and the attic appeared to be vented well.
Not overheated. Air gun shoot? :confused:

[Scott Patterson]

This is an example of what hail damage can look like;

[Ted Menelly]

Blistering is a result of moisture trapped in the shingle either during the manufacturing process, due to poor ventilation, installation over a wet substrate and a breakdown in mat layers. The blisters pop outward and you would see a cup shaped area with missing granules. When blistered shingles break open they can leave shingles susceptible to damage such as granule loss, color fading and may even lead to water leakage and should be replaced. While blistering shingles are rarely visible from the ground, a punctured blistered shingle will be easily spotted because it will likely appear to have black spots - which are actually the exposed asphalt shingle. You will want to advise clients to contact the manufacturer (if known) of the roof shingles that are blistering as this may fall under the manufactures warranty. Usually they will prorate replacement of material depending on the age of the roof, but won't include installation labor in settlement amounts.

Hail damage produces a bruised surface area with dimples similar to that made by a ball peen hammer strike. Areas of lost mineral granules will be apparent, with more severe granule loss on roof slopes facing the direction from which the hailstones fell (or blew) during the storm. Inspecting an asphalt shingle roof shortly after a hail storm, if the roof has been damaged, should show that the areas of mineral granule loss have exposed "fresh" looking shingle substrate - the asphalt impregnated shingle substrate will not yet have been weathered by sun exposure. You will usually see other areas of damage with hail such as dented aluminum roof vents, aluminum wrapped trim and even sometimes trim paint loss especially on wood window sills. I ask if I suspect hail damage as the seller may have already collected settlement from insurance company for hail damages and chose not to replace roof.

I would normally agree with all that with one exception. A roofer and home inspector inspected a roof that you will see in the tiny blisters link Jerry provided. It was not that the inspector found anything but the client was in a time crunch so she had a roofer there the same day. This was a week before golfball size hail desimated a good portion of Keller Texas.

I inspected the roof a week or so after the hail storm and those picks I put up on the tiny blisters thread is what I found.

Don't know what to tell you but that is what took place in a three week time period between a roofer and inspector inspected it....Hail storm....I inspected a week or so after.

Go figure.

[Jon mackay]

I am leaning towards the explanation that James provided, I do not believe that hail is the culprit.

Thank you for the info James