Water dripping down the wall or black fungal mould can be distressing but the culprit is likely to be condensation, not rising damp or structural damage. Damage due to condensation is rarely covered by insurance policies, but will dry out if you take sensible steps to minimize it at source.

First, know your enemy: common signs of penetrating damp are damp patches and staining on external walls and wet and crumbly plaster. You may also notice spores or black mould that are isolated to one area and drips and puddles beneath points of water ingress.

With condensation, you are more likely to notice a general feeling of humidity around the flat and a mustiness. There will probably be visible water droplets on surfaces, especially insides of windows, and when you touch surfaces your hands will come away wet. It’s time to turbo-charge your anti-condensation routine.


In its less serious form, condensation may only “steam up” windows and mirrors. In more severe cases, it can be absorbed by surface wall finishes and underlying plaster. So, you do need to take it seriously before that happens – and the remedies in the early stages are often quite simple. You cannot avoid condensation altogether, but you can minimise it.

There’s no mystery: the reason condensation appears in your property is due to a lack of adequate ventilation, which causes humidity levels to rise. The answer is to increase ventilation. One tip is to open windows whenever you can, getting the balance right between good ventilation and losing too much warmth.  Generally speaking, keep the place reasonably warm and energy efficient so the exterior walls don’t get so cold that water condenses on the inside.

Prevention, as ever, is better than cure, and reducing condensation is mainly a matter of common sense. Bathrooms and kitchens are the worst culprits for condensation, but every room in the flat has the potential to trap water in the air that can later reappear as condensation

Kitchen: Use pan lids and extractor fans when cooking if possible. Don’t confuse recirculating cooker hoods, designed to remove smells and grease not water, with an extractor fan. Even better, open a window as well. If your flat is not open plan, then close the kitchen door while cooking.

Install washing machines and vented dryers correctly. Do check behind the washing machine where condensation on the cold water hoses can eventually lead to mould. (We always say it’s a good idea to check behind the machine from time to time to be sure that inlet and outlet hoses are still tightly fitted and not dripping.)

Bathroom: It goes without saying that, when you are taking a shower or having a bath, you need to turn on your extractor fan if you have one.  Failing that open a window, if not while you are in the shower then as soon as you hop out and get wrapped in a warm towel.

If you need to dry clothes indoors, resist the temptation to drape them over radiators. Keep them behind a closed door in one room with an open window – probably the bathroom.

Living rooms and bedrooms: Do not overfill your wardrobes (or kitchen cupboards, for that matter).  Leave room for air to circulate. A musty smell is a sure sign that the cupboard is overfilled.

It’s also a good idea to make sure that your furniture is at least 50mm away from the surrounding walls so that air can circulate around the property. Ideally, big items like wardrobes can be placed against internal walls in your bedroom, which will be warmer than external walls, to reduce the risk of condensation causing mould behind them.

Water ingress

If you suspect water ingress, and if common sense measures to reduce condensation have not resolved your problem, your managing company should help you to seek professional advice from a builder or surveyor.

Over time building materials can deteriorate; and the best way to avoid water ingress is regular, planned building maintenance.  Some of the more common causes of ingress are listed below. They may be covered by the buildings insurance, which you pay for through your service charges, unless of course the building has been neglected and not maintained is reasonable order.

Roofs: missing or broken tiles or slates, ‘defective surfacing to valley gutters and flat roofs’, faulty flashing around chimneys.

Blocked or faulty gutters.

Walls: cracked render or deteriorating mortar, a bridged cavity wall or bridged damp proof course (DPC), missing DPC, blocked air-bricks, damaged or broken pipework

Windows: faulty flashing around window frames.

Rising damp: a failed or bridged damp proof course or even no damp proof course.

Faulty plumbing: strictly speaking, insurers call this escape of water, not water ingress and it is the single most common cause of insurance claims in blocks we insure.

So, whether it’s condensation, water ingress of escape of water; you can reduce the risk, the damage and the inconvenience by eliminating likely causes. Condensation in flats comes down to individual leaseholders; water ingress is a matter for the block managers. Ask them what planned maintenance they have for the building.


Reviewed 23 May 2022

The sole purpose of this article is to provide guidance on the issues covered. This article is not intended to give legal advice, and, accordingly, it should not be relied upon. It should not be regarded as a comprehensive statement of the law and/or market practice in this area. We make no claims as to the completeness or accuracy of the information contained herein or in the links which were live at the date of publication. You should not act upon (or should refrain from acting upon) information in this publication without first seeking specific legal and/or specialist advice. Arthur J. Gallagher Insurance Brokers Limited trading as Deacon accepts no liability for any inaccuracy, omission or mistake in this publication, nor will we be responsible for any loss which may be suffered as a result of any person relying on the information contained herein.