Roof Manufacturer Testing

Are their any testing methods that roofing manufacturer’s use to determine cause of wear or defects?

I inspected a house in September 05 that had a few areas of very damaged shingles (house is 1 year old). The contractor replaced shingles due to damages. Well, the roof is getting worse in the other areas and the manufacturer said they tested the material to find out that the roof was pressure washed (and it may have been pressure washed by the previous owner, why I don’t know)

Is this possible to determine if a roof was pressure washed besides just a visible inspection?

No blame on me… I am just trying to help a past client figure out how to handle it.


Not sure, but if was only one year old I can’t see why someone would have pressure washed it unless they were trying to remove mud or paint or something. It probably has defective shingles and the manufacture wants to avoid liability. You didn’t happen to get a pic of the shingles did you?

That is exactly what I was thinking…why within one year would someone think of pressure washing (ever). There are no trees within blocks.

I do have photos from September but I don’t know what the roof looks like now.

The seller said the manufacturer determined from a test they had done that it was from pressure cleaning. Go figure.

Here are some pics from september 2005. Most of the pics are from around the dormers.





Wow. That’s allot or granule loss. I can only see two of the pics good. If the dormers are brick, they may have got allot of cement on the roof and had to pressure wash it off causing this. But if this granule loss is evident on other areas of the roof not near any walls or penetrations, I would say the shingles must be defective.

Lets go CSI here…:wink:

The pattern on the shingles in some areas do look like that have been exposed to some sort of high pressure “wash”…but the other pictures look as if it is poor bonding of granular material … Perhaps poor quality or lack of mfg testing / QA testing.

Perhaps the ratio of “tar” or “adhesive” that is used to bond the granular material is poor or not holding .

What are the water patterns of pressure washer ? A high pressure stream from the nozzle concentrates the stream in a tight point. So in theory should be able to “carve” your name in the material . Also as the concentred stream of high pressure water gets farther away from the nozzle the pressure is lower. The surrounding mist of water has less force behind it so I would think that the area closest to the user would have the most damage.

What explains the shingles that have wear only on the very edges without any surrounding areas that are damaged too? hmmmmm :wink:

I have seen this type of damage in Northwest Florida. Tremendous amounts of mildew and algae growth during Spring and Fall (high humidity) have home owners calling for the pressure washers. A few of the people furnishing this service use clorox in concentrations of 1-2 cups to one gallon of water, leaving the solution on to “work” on the contamination. Result? Damage to the substrate when acted upon by the intense UV.

My first thought when I saw the damage was “wear” perhaps from boards, materials , etc used while working on the dormers. Most of the damage was around the dormers on the Southern side of the home.

These are all good ideas! Thank you for all the input.