Roofing/Roof stains


I have lots of roof stain and am not sure how or what it is. It appears to be a heavy rubbery substance, perhaps from surrounding trees. Someone suggested power washing, but I am reluctant. Power washing may remove some of the protective coating on the shingles and shorten its life.
In any event, have you experienced this type of a problem.
Thanks for volunteering.


I have not encountered the condition of which you speak, but if you have an opportunity, perhaps attaching a photo of the substance and an overall of the surrounding area may help.  Otherwise, power washing can be performed but I suggest a wide tip only as damage to the surface of the shingles is likely which will reduce the service life and the pressure may flip the tabs and break them.


Bruce Ryan II, RRO
Professional Roof Consultants, Inc.


All Answers

Answers by Expert:

Ask Experts


Bruce A. Ryan II, RRO


I offer solid knowlege of all types of Commercial and Residential Roofing, Waterproofing, and, Building Envelope systems. Experience ranges across low slope and steep slope roof systems. I am also well versed in matters regarding condensation and ventilation. I enjoy donating some of my time and knowledge to the betterment of others.


Bruce Ryan has 20 years of roofing, waterproofing, and building envelope consulting experience with PRC, with 5 years of commercial roofing experience prior to joining the firm. He became Vice President of the company in 1998. Bruce Ryan plays a key role in the development of practical, long-term roofing and waterproofing solutions, along with implementation of on-site forensic studies. Bruce also has a high level of experience with regard to the impacts of roofing materials and construction for demanding clients with heavily occupied structures.

Oregon Construction Contractors Board Construction Specifiers Institute National Roofing Contractors Association The Institute of Roofing, Waterproofing, & Building Envelope Professionals Oregon Board of Investigators Installation Masters

University of Maryland BS Business & Administration Registered Roof Observer - RCI Private Investigator Certified EIFS inspector - Northwest Wall and Ceiling Bureau Certified InstallationMaster™ - The Installation Masters™ Training and Certification Program (developed by American Architectural Manufacturers Association)

©2017 All rights reserved.