Interstitial condensation control in pitched roofs
What it looks like
Inadequate design or installation of insulation and ventilation systems, leading to trapped moisture and structural damage.
Why it happens
To prevent condensation in larger pitched roofs containing insulation, the design must actively limit the risk of interstitial condensation. This requires a well-considered roof ventilation strategy, often guided by comprehensive flow charts and design guidance, to ensure moisture is effectively managed within the roof structure.
What it costs if it is missed
To prevent condensation in larger pitched roofs containing insulation, the design must actively limit the risk of interstitial condensation. This requires a well-considered roof ventilation strategy, often guided by comprehensive flow charts and design guidance, to ensure moisture is effectively managed within the roof structure.
How to inspect for it
Confirm that the roof design, including insulation and ventilation, aligns with the specified condensation control strategy.
How to prevent it
To prevent condensation in larger pitched roofs containing insulation, the design must actively limit the risk of interstitial condensation. This requires a well-considered roof ventilation strategy, often guided by comprehensive flow charts and design guidance, to ensure moisture is effectively managed within the roof structure.
Basis in regulation
BS 5250
Read the source
Last updated 23 August 2026. This is our editorial summary of publicly available regulation and site practice, not building control approval or a warranty determination.