Kitchen condensation that keeps returning | Homecode

What is known — and what is not

Separate vapour from a water leak

• Droplets that appear on several cold surfaces during cooking may fit condensation, while still leaving the ventilation cause unresolved. [1]
• A cooker hood may recirculate air rather than discharge it outdoors, so noise alone does not establish moisture extraction. [2]
• Wetness centred below a sink, appliance, joint or service route and linked to water use may indicate a leak. [1]
• A high-level mark that follows rain may indicate an external or roof water path rather than cooking vapour alone. [1]

Low-risk checks

• Photograph the first wet surface and record cooking, sink, appliance and rain timing. [1]
• Check labels and already-visible duct information without removing any component. [2]
• Use an installed external extract or kitchen fan through its normal control and note sound, indicator and apparent failure. [2]
• Photograph accessible drips or stain growth without pulling out connected appliances or opening pipework. [1]

Boundaries that prevent a wrong repair

• Do not claim that a recirculating hood alone provides the kitchen extract described by Approved Document F. [2]
• Do not remove a fan grille, alter a duct or fire damper, touch wiring or dismantle a water-using appliance. [2]
• Do not attribute wet cabinet bases or floors to humidity until plumbing and appliance water routes have been assessed. [1]
• Keep away and obtain urgent help where water reaches electrical equipment or active flow is damaging the property. [1]

Match the professional to the evidence

• Use a ventilation professional to establish the discharge route and assess the kitchen's required extract provision. [2]
• Use a competent plumber for a concealed, ongoing, pressurised or water-use-linked leak. [1]
• Use an independent building professional if vapour, leakage and external fabric evidence remain mixed, and require a written cause and scope before any remedial decision. [1]

Property, sale and letting implications

• Persistent moisture may swell cabinet materials, damage finishes, encourage mould and transfer vapour to colder rooms. [1]
• For a future sale, retain extraction information, leak findings and completed-work records so the history is not limited to cosmetic repair.
• An English tenant should report recurring condensation, mould, fan faults and suspected water leaks to the landlord or agent. [3]

Frequently asked questions

• Why is there condensation when the hood is on? The hood may recirculate, or an extract system may be ineffective; sound is not an airflow test. [2]
• Is water in a cupboard condensation? It may be, but plumbing, waste and appliance leaks should be excluded first. [1]
• Should I order a larger fan? Not until the current system, discharge route, background air and possible leaks have been assessed. [2][1]

Review triggers

• Review if H3 revises kitchen-extract, fan-observation or plumbing-leak rows.
• Review after a change to Approved Document F or national damp guidance.