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Roofing/slot in deck for ridgevent


QUESTION: Hello Bruce,
I have a gaf camelot 2 shingled roof. For a number of reasons, I asked my roofer to remove my existing cobra ridge vent that was installed. He pulled off the vent and installed the timbertex cap shingles. He did NOT cover the slot with wood or put down any underlayment over that slot--just ridge caps.  After I asked him about this, he said he didn't see any reason for either. But I want to get a second opinion. What do you think? If you believe that the slot does need to be covered with wood and/or underlayment--could you point me to a resource? Thanks so much!"


Try this link

Basically the material is not intended to be self supporting and it is required to be backed up by underlayment.  It may hold up for a year or two, but at some point the peak of the shingle will collapse and ultimately invert, resulting in leaks.  Hot days or someone walking on the ridge will accelerate the process.

I recommend you remove them, add the strips of plywood sheathing for support install underlayment over the ridge lapping onto the last course of shingles, and reinstall the ridge shingles.

Bruce Ryan II, RRO
Professional Roof Consultants, Inc.

---------- FOLLOW-UP ----------

QUESTION: Thanks Bruce.  Do you have a resource that states that the ridge caps must have sheathing and underlayment? I cannot find that support in the doc you provided and I'll need it to show the roofer. Thanks so much in advance!


In the ICCES Evaluation Report I cited, look at Item 4.1.1.  It states that shingles must be installed over sheathing.  That means they have to be continuously supported by wood.  The hip and ridge components are shingles.  They need to be continuously supported by wood, or as stated in Item "...(or over shingle-over ridge vents)..."

I really don't expect that there is any further supporting documentation.  Frankly, your roofer should know better; it pretty much goes against common sense.


Bruce Ryan II, RRO
Professional Roof Consultants, Inc.


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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)

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