Should you be worried about condensation?

Keeping on top of your property maintenance is important and damp is one of the things you should keep an eye on. So when is condensation a problem?

For the most part, a few beads of condensation on your window is nothing to stress about. Whatever type of home we live in, and whether we own or rent, we’re all bound to encounter condensation. 

But if you’re seeing – or your tenant’s are reporting – any of these, there could be cause for concern: 

  • Water trickling down windows
  • Cold walls that are damp to the touch 
  • Mould growing in the house

Where does the condensation come from?

When warm, humid air meets a cold surface, the moisture in the air turns into beads of water, which form on the surface.

This is why you’ll often see condensation on windows – because the warm air from your home is coming up against a window that reflects the temperature of the cooler outdoors – but it can also form on walls and other surfaces.

Is condensation worse at certain times of the year?

Warm air usually holds more moisture than cold air, so it might seem surprising that the worst time for condensation is the cooler months, normally October to April. 

So, why is this? 

Well, advances in building materials and techniques have worked against us a bit, with modern homes being so well insulated and sealed that the moisture doesn’t have the opportunity to escape as it might do in an older home. This doesn’t matter in the summer months, when we fling open the windows and patio doors and our homes get plenty of ventilation. 

But come winter, when we shut out the cold, dark evenings, the moisture level can build up without us realising.

Why is my home so humid?

Many of our daily routines create moisture in the air, from boiling the kettle and cooking dinner, to having a bath or shower and drying clothes. This is even more of an issue in a small flat, as there often isn’t the space for a tumble dryer and no outside space to dry clothes when it’s not raining.

Our bodies also create moisture in the air, with the average person adding half a pint of water to the air overnight, just by breathing – and that rate doubles when we’re awake. In fact, on average a family of four will produce an astounding 24 pints (14 litres) of water vapour in 24 hours (!!).

Will condensation harm my health?

Condensation won’t hurt you in and of itself, but it’s more about the environment it creates –  and what likes to live in that environment…

Mould and mildew love humidity, which means they can take hold and then grow – and become airborne. That’s when they pose a health risk:

  • Runny nose
  • Dizziness 
  • Sore throat
  • Asthma attacks
  • Breathing difficulties
  • Irritation of the sinuses and nose
  • Infections

Some people are more at risk than others, with the following groups being particularly vulnerable:

  • The elderly
  • Babies and young children
  • People with skin conditions (e.g. eczema)
  • People with respiratory problems (e.g. asthma and allergies)
  • People with a weakened immune system

What will condensation do to my home?

So, we know that condensation is a perfect habitat for mould and mildew. As well as being rather horrible to look at, mould and mildew can affect the things it lives on. 

For instance, you may see black mould growing in the corner of your window, or a corner of your room, and if left to its own devices it can stain paintwork and other surfaces, and/or degrade them over time. 

And as it can become airborne, it can start to affect things throughout your home, not just the site of the condensation problem.

Will condensation damage my home structurally?

Surely a bit of moisture can’t damage bricks and mortar? 

Well, not only can the moisture seep into the walls over time and affect the structure, but it also throws its weight around in a surprising way: Humid air has a higher pressure than dryer air. If there’s a difference in moisture levels on two sides of a wall, the higher-pressure air will push against the wall in an attempt to equalise pressure. 

Over time this force can do things like make paint peel and blister, stain walls and ceilings, and impact floors, joists and even the foundation.

So you want to make sure that your Buildings Insurance policy covers you for any structural damage that could have been caused by damp.

Are tenants responsible for dealing with condensation in my rented home?

Who’s responsible for mould in a tenant–landlord situation can be a somewhat grey area. 

If you’re a tenant, you’re expected to ensure you heat and ventilate your home well enough to prevent a build-up of damp – and let’s face it, it’s in your interests to do this, as no one relishes living in a mouldy home. 

However, if the source of the condensation problem is inadequate maintenance – for instance, the roof’s been leaking for months or the damp-proofings in need of replacing – that’s the landlord’s responsibility.

What steps can I take to reduce condensation in my home?

Whether you’re a tenant or homeowner, you can help manage condensation by:

  • Opening the bedroom window for a while after you get up in the morning
  • Using existing extractor fans (especially in kitchens and bathrooms)
  • Closing doors to other rooms when cooking or showering
  • Putting lids on pans while cooking
  • Keeping furniture and belongings away from external walls
  • Drying clothes outdoors or in a tumble dryer
  • Maintain steadier temperatures, e.g. by (energy prices permitting) leaving the heating on low even when the house is empty or following our tips to guard against heat loss
  • Consider buying a dehumidifier, and/or a humidity monitor

If you’re a landlord, it’s vital to keep in mind you have a legal responsibility and a duty of care to your tenants to ensure your property is free of damp and mould. Therefore it’s wise to:

  • Carry out all maintenance and repairs promptly
  • Talk to your tenants about their important role in dealing with condensation (you can share the tips above!)
  • Install extractor fans in kitchen and bathroom areas
  • If replacing windows, opt for a trickle vent, or a lock that allows windows to be locked slightly open, for ventilation
  • Take steps to ensure your property is easy to keep warm
  • Make sure your landlord insurance covers flooding and storm damage, as such events can lead to mould and damp issues

Condensation is a fact of life, whatever our living situation. The good news is that it needn’t cause any trouble provided properties are well looked after, heated and ventilated.

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