Management of Moisture in Buildings - Pitched Roof Designs

Description

This RIBA-approved CPD explores how moisture moves through building envelopes, the causes of condensation, relevant standards and practical design considerations, with a focus on pitched roof design. It provides practical, technically sound guidance on managing moisture in pitched roofs, looking beyond compliance to how roofs actually perform in practice.

The session explores the gap between design compliance and performance once a roof is built and occupied. Why can a roof that appears compliant still experience condensation? How do construction moisture, changing occupancy patterns, increased insulation and improved airtightness affect the way moisture behaves within the roof structure?

Participants will examine the key mechanisms that drive moisture movement and the interaction between ventilation, roofing underlays, insulation and ceiling airtightness. The CPD considers cold, warm and complex pitched roof constructions, highlighting why moisture management needs to be assessed across the complete roof build-up.

Drawing on BS 5250:2021, BS 9250:2007 and NHBC guidance, the session explores how underlay selection, roof geometry and the air permeability of roof coverings influence ventilation design. It also considers the implications of in-roof solar installations and the role of third-party certification where limited or no roof-space ventilation is proposed.

Designed for architects, specifiers and construction professionals, this CPD supports informed design and specification decisions, helping participants identify condensation risks and reduce the likelihood of moisture-related defects after completion.

Learning outcomes:

By the end of this CPD, participants will be able to:

• Identify the key condensation risk points in modern pitched roof designs.
• Apply BS 5250:2021 correctly to cold, warm and complex roof structures.
• Evaluate when roof coverings should be treated as air permeable or impermeable.
• Understand how in-roof solar and airtightness strategies change ventilation design.
• Reduce the risk of post-completion condensation claims and warranty issues.