06
Jan
Window condensation can be a homeowner’s worst nightmare, particularly during the colder months as temperatures drop.
If left untreated, it can cause long-standing cosmetic and structural damage to your windows and negatively impact your health and quality of life.
We’ve put together this helpful window condensation guide that explores some of the most common causes, explains how to safely remove it, and looks at some of the preventative measures you can take to reduce it and stop it from coming back.
Condensation is the result of a vapour or gas converting into a liquid.
This process can occur when the temperature of an object, like the glass pane of your window, for example, drops below what is known as the ‘Dew Point’ temperature.
The Dew Point is the temperature at which air must be cooled to become saturated with water vapours.
Dew point temperatures can vary with conditions and the amount of water in the atmosphere. In warmer environments, condensation can occur at higher temperatures, while in colder conditions, it can also happen despite the lower humidity.
No area of your home is immune to condensation. It is most commonly associated with windows and doors, where there is the clearest visual cue of a build-up of water.
It can also build up on walls and ceilings.
Depending on the location of the condensation in your home, the cause and solutions can change – something we’ll tackle later in this guide.
The internal side of your glass is a pertinent surface for condensation to occur if the temperature of the glass is too low when compared to the water vapour contents of the room’s atmosphere.
This is the most common example of condensation on windows and can result in pools of water forming around the corners of the glass.
This can be detrimental to both you and the window if left for long periods.
Condensation on the outside of your window is a good sign. It shows that the window is performing as it should thermally by preventing internal heat loss.
This can form if the external temperature of the glass falls beneath the dew point temperature.
It doesn’t require clearing and will dry naturally throughout the day as the external temperatures rise.
Having double or triple-glazed glass means that your outer pane of glass is not heated by any lost heat that is escaping from your home.
As a result, condensation on the outer surface of your windows is more common during spring and autumn through a combination of high humidity and colder weather conditions.
Condensation can occur within the cavity when damp air has penetrated a gap in the seal.
A double-glazed window is a sealed unit and shouldn’t let in any air.
If the cavity is no longer airtight, the original seal has failed. This cannot be repaired, and the unit should be replaced.
In layman’s terms, condensation is caused by warmer excess moisture hitting a cold surface in your home.
The differences in temperature between your internal and external environments will cause condensation to form.
If you have warm moisture in your home and the temperature of your glazing is cold enough, the molecules come together to form a visible liquid that sits on your glass surfaces.
Condensation in new builds is a common occurrence. This is not a fault of the build and in many ways, is unavoidable. As a result of the sheer volume of materials such as concrete, paint, and plaster that were used during the build, excess moisture is trapped inside the property.
This can be particularly pertinent if the build occurs during adverse weather conditions.
That moisture needs time to escape and this is often known as the ‘drying out’ phase of a new build.
This is a process that can take between six to 12 months to resolve itself. It should do just that with regular ventilation from the homeowner, however, if your issues persist over time, we would recommend contacting NHBC.
Although it can’t be helped, breathing is a big contributor to the excess moisture in our homes.
According to the Glass and Glazing Federation, two adults release on average one litre of moisture over eight hours while they sleep.
Steam from saucepans and kettles is one of the most common sources of steam in our homes. This can be managed by using extractor fans while cooking, or covering saucepans with lids.
A combination of washing machines, tumble dryers and damp clothes being left to dry inside can be a major contributor to excess moisture being trapped in our homes.
If you do need to dry clothes indoors, do so in a well-ventilated room and consider using a dehumidifier nearby.
Double-glazing can prevent the build-up of condensation on your windows by acting as an insulation source.
With heat sources like radiators often positioned near windows, double glazing reduces thermal transmittance and retains the heat inside your property.
By doing so, your internal pane of glass stays warmer than the outside temperatures, thus preventing the build-up of moisture.
Triple-glazing takes that protection one step further with greater thermal performance compared to double-glazed windows.
Triple-glazed windows have better U-values, which means less heat is lost through the glass, and the better your home is insulated.
For example, when double-glazed, the Rationel AURAPLUS has a 1.29 W/m2K U-value, but when triple-glazed, this drops to an impressive 0.78 W/m2K.
With triple glazing, more insulation is afforded to the internal pane to keep it warmer than the outside temperatures to prevent condensation.
Approved Document L: Conservation of Fuel and Power within current Building Regulations stipulates that any new or replacement windows must meet minimum performance criteria.
Persistent, untreated condensation is bad news for your windows. Over time, it can reduce the life span of your windows through structural damage, discolouring or rotting, depending on the material.
Pools of sitting water on your windows will also encourage mould growth, which in itself can have serious health risks for homeowners.
Damp and mould growth can be linked to respiratory problems and infections, and should be taken seriously as part of your routine care and maintenance.
If you experience condensation in your home, use a dry, clean cloth to remove any water buildup. You can also use a window squeegee to help clear the surface.
Ensure you dry the area as best you can when cleaning to minimise any moisture left on the surface.
This is not going to be a long-term solution that prevents future condensation, but it will help protect your windows and your health in the short term.
If condensation is pertinent to one particular area of your home, you could consider using a dehumidifier to draw out any remaining excess moisture, as well as ensuring that the room is regularly ventilated by opening windows.
To stop condensation, you need to ensure all rooms are well-ventilated, even during the colder months.
Regular ventilation throughout your home is crucial to preventing and reducing future condensation.
There are some additional things you can do around your home to help stop condensation, so we’ve compiled some helpful tips to you can add to your everyday routine.
Single-glazed units will not offer as much protection against condensation when compared to double or triple-glazed units.
With a single-glazed unit, there is no additional protection between the internal side of your glass to the external side. As the temperatures drop outside, your single-glazed glass won’t be able to warm up enough.
This is particularly important for older properties, where single-glazed units will be more common. Drastic measures may be required to tackle the condensation issue.
It is recommended that you open each window in your home for between five and 20 minutes every day, even during the winter.
This can be done by opening a window slightly or having trickle vents installed, leaving moist warm air free to escape and allowing cooler, dryer air to enter your home.
While it may seem counterintuitive to have windows open in the winter, cooler, dry air is more affordable to heat than warmer, moist air.
Where they are installed, trickle vents should be left open at all times to prevent condensation build-up.
More information about trickle vents and their benefits can be found in our Windows and Doors Care and Maintenance Guide.
If you have a gas or oil heater installed in your property, consider permanent ventilation solutions in these rooms to prevent condensation build-up.
Don’t forget about empty or spare rooms. While you might be tempted to turn off the heating in that room, maintain its temperatures and ventilation levels in line with the rest of the house.
Water vapour travels through your home and is not limited to the room in which it is produced.
Check internal doors for draughts and consider closing doors where possible. Trapping moisture build up in one room/area of the home will make it easier to dispel.
Installing extractor fans in your kitchens and bathrooms creates another form of escape for moisture when these rooms are being used.
Where the weather allows you to do so, always dry wet clothes outside. If you do need to dry clothes inside, ensure you do so in a well-ventilated room that allows resting moisture the chance to escape.
When you first notice moisture building up around your windows, remove it as quickly as you can safely to prevent any mould growth or damage to your windows.
As per Home Building, the average UK household should have a humidity range between 50 and 55%rh (Relative Humidity).
However, in the winter months, this figure will be lower and closer to 40% to prevent condensation from forming on the windows.
You can easily monitor your home’s humidity levels using a hygrometer, which can easily be purchased online, or from your nearest retail DIY store.
Dehumidifiers have become a popular investment among homeowners looking to lower their home’s humidity.
They can be a helpful tool when you need to dry laundry inside or just remove excess moisture from a room.
Choose your house plants carefully. Depending on the type, they can be as damaging as they can be effective.
Plants like a Peace Lily or Aloe Vera can be carefully positioned around your home to absorb excess moisture and still look like a worthy element of your home’s décor.
Too many plants and you can risk adding too much excess moisture to the atmosphere.
As well as the natural ventilation techniques outlined above, you can manufacture air circulation around your home by using a fan.
Combined with natural ventilation, this will help reduce your home’s humidity levels.
Ensuring you take preventative steps to control the amount of moisture in your home is the most effective solution to combat condensation.
The superior insulating properties of glazing make it one of the most effective solutions.
However, there are not always short-term fixes to solve condensation and regular ventilation, as well as the routine care and maintenance elements outlined above are paramount in the long run.
If you would like to learn more about our glazing solutions, book a showroom appointment or contact our team to discover how Aspect Windows can support your next project.
We’ve also put together some helpful window condensation FAQs to give you some quick answers for any queries you might have.
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