Kitchen condensation and mould: why it happens and what helps

Kitchen condensation happens when moisture from everyday activities, especially cooking, meets a colder surface and turns into droplets. If that moisture stays, mould can develop. The practical answer is to remove moist air, wipe away condensation and check whether a building defect or another source of water is adding to the problem. Cleaning the mould alone will not settle an ongoing moisture problem.

Why it shows up in the kitchen

Cooking puts moisture into the air. When it cannot escape, it can settle on colder parts of the room, including windows, walls and corners. You might first notice beads of water on glass or a patch on a cold wall. That pattern suggests condensation, but it does not tell you that cooking is the only source of damp in the room.

A kitchen can have more than one moisture problem at the same time. Government guidance says water damage from outside the home can make condensation worse. If a patch is closely tied to rainfall, a window opening or an external wall defect, it deserves a closer look alongside the room's ventilation. Treat the evidence as a whole rather than assigning every mark to cooking.

Let moisture out while you cook

Use the kitchen's ventilation when cooking and check that it works. Government guidance says kitchens should, where possible, have an extractor fan connected to outside or to a central unit, placed close to the hob for best effect. A hood over the cooker is also advised. A fan that merely runs without effectively removing moist air needs investigating, particularly if condensation keeps returning.

RICS advises keeping the kitchen door closed and opening a window while the room is in use. This helps keep the moisture from spreading through the rest of the home. Avoid blocking existing vents, which allow air to circulate. These are small everyday steps, but they work best when the building has adequate ventilation to begin with.

Wipe visible condensation from cool surfaces, including windows and kitchen tiles. RICS suggests using a dry cloth or sponge. If water repeatedly gathers in the same place despite ventilation, note exactly where and when it appears. That pattern can help show whether the room needs better moisture removal or whether another cause needs attention.

What to do about the mould

First deal with the moisture source. For a small amount of mould on a hard surface, government guidance says an appropriate mould and mildew cleaner can be used and the area should be left to dry completely. It recommends a mould and mildew product in preference to bleach. The surface may look clear after cleaning, but mould can return if the damp conditions remain.

Larger areas of mould need a qualified professional. Absorbent items can be much harder to clean completely than a hard kitchen surface. If mould is spreading, recurring or appearing along with obvious water damage, give the underlying problem priority. A quick clean should not become the entire response to a persistent damp area.

If you rent, tell your landlord about the mould and any condensation or water damage you have seen. Explain whether it appeared after a change to ventilation, heating or the building, and whether it varies with rain. Government guidance tells landlords to identify and tackle underlying causes, including building deficiencies and inadequate ventilation, rather than relying on surface cleaning.

A Yorkshire and Lancashire kitchen with a cold wall

In a stone terrace or solid-wall home, a cold external kitchen wall can be where indoor moisture first becomes visible. A wall in that position is worth examining, but its location alone does not settle the cause. Check whether the room can clear moisture during cooking and whether any outside water is reaching that wall. The two issues can overlap.

It is easy to blame a household routine when droplets appear around a kitchen window. Yet an extractor that does not remove air, a blocked vent or a defect outside calls for a different response. Keep notes of where the patch starts and what makes it worse. That gives a landlord or surveyor something concrete to investigate rather than a vague report of ‘mould in the kitchen’.

When the usual steps are not enough

If ventilation, wiping condensation and addressing an obvious defect do not stop the damp from returning, seek an independent, suitably qualified surveyor with relevant damp experience. Ask them to identify every likely moisture source and explain what evidence points to each one. A persistent patch may need a building investigation as well as better ventilation.

The useful test of any proposed fix is simple: does it tackle the source of the water? Better extraction may be needed where cooking moisture cannot escape; a building defect needs its own repair. Once the cause has been addressed, watch the area for a return of condensation or mould and revisit the explanation if it comes back.

This page gives general information, not legal or medical advice. For your own situation, use the organisations listed under "Where this comes from" at the foot of the page.