Condensation is one of the most common problems homeowners notice on their windows. At first glance, it may seem like a small issue, but it often leads to questions about whether something is wrong with the glass, the seals, or even the insulation in the home. To make matters more confusing, condensation can appear on the inside of the glass, on the outside, or even between the panes of double glazing. Each type of condensation has different causes and solutions, so it is important to know the difference.
At RPS Double Glazing Repairs, we often get asked about condensation and whether it means that the windows need repairing or replacing. This article will explore the difference between internal condensation and external condensation, why each occurs, and what can be done to deal with it. Along the way, we will also highlight how our services such as misted double glazing repairs, replacement double glazed units, and general window repair can help homeowners across Bournemouth, Poole, Ferndown and the surrounding areas.
Internal condensation forms on the inside surface of the glass, facing into your home. This happens when the warm air indoors, which carries moisture from everyday activities like cooking, washing, or drying clothes, meets a colder surface such as the glass of your window. The water vapour in the air cools down, turning into visible droplets of water.
Internal condensation is very common in homes that have poor ventilation or where the indoor humidity levels are high. It is especially noticeable in winter when the temperature difference between inside and outside is greater. Over time, repeated condensation can cause mould growth around the window frames, peeling paint, and damage to plaster or wallpaper.
For homeowners, this type of condensation can be frustrating. It often points to an underlying issue such as poor airflow, ineffective trickle vents, or inadequate insulation. While some solutions involve improving ventilation, sometimes the windows themselves need attention. That is where services like window repairs, upvc window repairs, and full window repair work from RPS Double Glazing Repairs can make a real difference.
External condensation appears on the outer surface of the glass, facing outdoors. Many people see this and assume that something must be wrong with their windows, but in reality, external condensation is usually a positive sign. It often means that the glass is highly energy efficient.
The science behind it is simple. On a cool morning, the outside air can be colder than the outer layer of your double glazed window. If the outer glass surface cools below the dew point, moisture in the air condenses on it. Far from being a fault, this indicates that the inner glass and the home itself are well insulated, preventing indoor warmth from escaping and heating the outer pane.
External condensation is temporary, usually disappearing as the sun warms the glass or as the outside temperature rises. Unlike internal condensation, it does not cause damage to your property.
There is also a third type of condensation that homeowners often encounter: misting or condensation trapped between the panes of double glazing. This occurs when the seal around the glass unit fails and moisture enters the air gap. Once this happens, the insulating properties of the window are reduced, and the glass often looks permanently fogged.
This is where misted double glazing repairs and replacement double glazed units come into play. At RPS Double Glazing Repairs, we can replace the failed glass unit without needing to install entirely new frames, saving homeowners money while restoring clear views and insulation.
It helps to think of condensation as a simple reaction between warm moist air and a cool surface. Internal condensation is usually a problem, while external condensation is typically a sign of well performing glass.
Internal condensation: Indicates excess moisture indoors and may point to issues with ventilation or insulation. Can lead to mould, damage, and discomfort if left untreated.
External condensation: A natural occurrence that shows your windows are energy efficient. Usually clears on its own and does not damage your property.
Condensation between panes: A sign of a failed sealed unit that requires repair or replacement.
Knowing the difference can save you unnecessary worry and ensure you take the right action.
Our team specialises in all aspects of double glazing repair. If you are noticing persistent condensation inside your home, we can check whether your windows need sealing, repairing, or upgrading. For those with failed glass units, our replacement double glazed units service restores the efficiency of your windows quickly and cost effectively.
We are also experts in window repairs Poole, double glazing repairs Bournemouth, and double glazing Ferndown, supporting homeowners right across Dorset. From simple upvc window repairs to more specialised fixes like replacing a faulty swiggle strip, our team provides long lasting solutions.
By repairing rather than replacing entire windows, we help you extend the lifespan of your frames, save money, and improve the comfort of your home.
Condensation is a natural occurrence, but understanding where it appears and why makes all the difference. Internal condensation is often a sign that your home needs better airflow or possible window attention, while external condensation is usually nothing to worry about. If you spot misting between the panes, that is a clear indicator that repairs are required.
At RPS Double Glazing Repairs, we provide practical solutions including misted double glazing repairs, replacement double glazed units, upvc window repairs, and general window repair. Whether you are in Bournemouth, Poole, Ferndown, or the wider Dorset area, our expert team can restore your windows and keep your home comfortable and efficient.
Contact RPS Double Glazing Repairs today for friendly advice, free quotes, and professional services that you can rely on.