Condensation risk assessment for floors
What it looks like
Inadequate condensation risk assessment can lead to interstitial condensation, causing structural damage or unhygienic conditions within the floor void.
Why it happens
The potential for condensation within structural floors, including flat roofs, must be thoroughly assessed during the design phase. This assessment helps to prevent moisture accumulation that can lead to material degradation, mould growth, and reduced thermal performance.
What it costs if it is missed
The potential for condensation within structural floors, including flat roofs, must be thoroughly assessed during the design phase. This assessment helps to prevent moisture accumulation that can lead to material degradation, mould growth, and reduced thermal performance.
How to inspect for it
Verify that a condensation risk analysis has been completed for floor structures, particularly those involving cold deck arrangements or significant insulation layers.
How to prevent it
The potential for condensation within structural floors, including flat roofs, must be thoroughly assessed during the design phase. This assessment helps to prevent moisture accumulation that can lead to material degradation, mould growth, and reduced thermal performance.
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.