You are here:

Roofing/attic moisture/ventilation issue


We recently purchased a 2-story home where a large amount of black mold was found in the attic.  We negotiated the price down and agreed to take care of getting the mold taken care of.  We hired a mold remediation company who came and said they couldn't find the source of moisture (this took place in Ohio in May).  So they sprayed the attic and installed two gable vents and a power vent fan.  The house already had continuous soffit vents the entire length of both sides of the roof and a ridge vent as well.  6months later I went up to check the attic and found the mold to be starting to come back along with the surface of the insulation to have tiny beads of water/moisture.  I began to explore and found both bathroom exhaust vent hoses just vented "into" the soffit.  So I cut two 4inch holes in the soffit and attached an louvered end piece on to each vent hose so the exhaust exited to the outside instead of just into the soffit to be returned into the attic.  The mold remediation company came and sprayed the attic again, adjusted the settings on the power fan, and sealed off some of the ridge vent...stating the power vent would work better that way.  It's been 1-2 months (December) and the mold is returning, the insulation is still wet.  The power vent runs 15-20 hours a day.  I don't know what to do!!! From reading online, my mold company doesn't understand attic ventilation!  But, I've read so much online that I'm confused on what to do.  I assume the soffit vents work; the baffles are keeping the insulation back. I turned off the power vent. Should I cover up the new gable vents? How do I know if my ridge vent is working?  Other than the two bathroom vents that were venting into the soffits, why would the attic be full of mold ORIGINALLY (prior to the power vent and gable vents)???? Could it be that the ridge vent doesn't work??? I am fairly certain that I need to seal off the gable vents and power (if I understand it correctly that these compete or short circuit the soffit and ridge vent circulation). But the mold came prior to those, so that's where I get stuck.  Any suggestions you have would be appreciated.


It sounds like I will not be able to solve your problem from here.  I suggest you visit  Roof Consultants Institute.  There you should be able to easily find a few qualified building science type experts that can independently identify your problem and recommend a correction/solution.  Any 'PROFESSIONAL MEMBER' will not provide contractor services so you can put faith in their recommendations.

Excess moisture can come from many sources within the home.  A moisture study can be performed to track the moisture build up issue and careful knowledgeable expert evaluation should result in adequate corrective action.  Mold remediation companies are not building scientists.

The consultant will not be inexpensive but you should expect nothing but the best results.

Here is to a condensation free 2016!  Keep me posted if you will,

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.

[an error occurred while processing this directive]