Using Roof Build-ups to Manage Moisture in Low U-Value Buildings and Provide a Healthier Environment for Occupants

Description

This RIBA CPD explores how roof build-ups can be used to effectively manage moisture in low U-value buildings, helping to prevent condensation and create healthier internal environments. Beginning with Approved Document C and BS 5250:2021 Revision and its whole-building approach to moisture risk, the CPD goes on to focus on optimised cold and warm roof constructions, explaining how ventilation strategies, insulation placement, and correctly specified vapour control layers work together to control interstitial condensation. Through practical examples and condensation risk analysis, it highlights the importance of airtightness, thermal bridging mitigation, and correct detailing at eaves and ridges. The session also considers the role of Mechanical Ventilation with Heat Recovery (MVHR) systems in maintaining balanced humidity levels, concluding with key design principles to support durable, compliant, and moisture-resilient roof solutions.