Condensation in Steep Slope Roof Systems

How breathable, vapor-open roofing underlayments mitigate water intrusion - extending the life of the roofing assembly.

• Describe the history of roofing underlayments.
• Understand the difference between asphalt felt and synthetic underlayment.
• Define the roof assembly barriers; heat, air, moisture.
• Articulate why a breathable roofing underlayment provides superior drying capacity over conventional roofing underlayments.
• Understand key details when installing a roofing underlayment.

Presented by:      Scott D Wood Senior Building Scientist, Vaproshield

When condensation is not properly managed, it can wreak havoc on roofing systems, including damaging the underlying substrate, framing materials, and interior moisture sensitive components. Proper selection and installation of the roofing system components plays a vital role in the performance of the building’s roofing and thermal systems and goes a long way towards minimizing leaks and condensation.

• Learn about the properties of condensation and why it occurs in roof assemblies.
• Learn about different roof assembly types and code requirements to mitigate condensation.
• Explore case studies of different roof assemblies where condensation resulted in a failure of the roof system.
• Discuss the effects of ventilation and moisture control on non-vented roofs and vented roofs.
• Learn about repair designs and methodology for different case studies.

Presented by:      Edward Fronapfel, MSCE, P.E. SBSA; Heidi Klein MSCE, P.E.

Venting steep slope roof systems is not only a code requirement it is an effective means to manage moisture within the roof assembly.

• How cold climates like Colorado’s affect condensation in steep slope roof systems.
• Building code requirements for steep slope roof ventilation.
• Vapor retarders and air barriers as part of the solution.
• Types of intake and exhaust venting.
• What happens when steep slope roof systems are not designed and installed to mitigate the risk of condensation?

Presented by:      Dan Cupit - Professional Construction Services