Western Roofing Expo 2017

Leaky Exhaust Vents – The 500lb Gorilla of Condensation Problems when Re-Roofing Multi-Unit Residential Units (Room Champagne 1)

13 Jun 17
8:45 AM - 10:00 AM

Tracks: Business, Low Slope, Steep Slope, Safety, Legal, Business, Human Resources

Speaker(s): Phil Dregger, PE, Technical Roof Services

Many factors contribute to excessive condensation in low slope roof systems installed over wood decks with insulation below; high interior RH, high solar reflectance, and especially air intrusion.  Another contributor, the impact of warm humid air leaking out improperly terminated exhaust vents, is like the proverbial 500lb gorilla.  We are aware he’s in the room but not sure what to do about him.  When this guy creates a serious problem, however, roof professionals are often asked to explain why they did not “correct” the improper exhaust vent termination conditions before installing new flashing assemblies over them.  This presentation will explain why complete discharge of exhaust air is so important; code requirements for termination of exhaust vents; and ways to avoid exhaust vent related condensation problems.