The most common cause of damp in a building is condensation, and windows are a major source of it.
If you can absorb condensation from windows, you’ll be taking effective steps towards combatting the problems it causes.
Why is condensation a problem?
Condensation occurs when warmer, moist air meets a cool surface. The air cools, but can’t retain the moisture and so releases it into the atmosphere.
If moisture caused by condensation is left on surfaces, it can prompt mould to form.
Windows do not cause condensation, but they can be a perfect breeding ground for it because they are the coldest indoor surfaces.
Indoor air is humid, mainly through everyday living, and during colder months the air is much warmer than that outside. It contracts as it cools, and moisture condenses on window glass.
Condensation is often first visible on your windows but is likely occurring in other areas and can lead to the deterioration of plaster, wallpaper, paint and woodwork.
It can also occur between windowpanes where there is double glazing, forming too on the exterior of windows.
What then can you do to absorb condensation from your windows and help prevent condensation?
How to tackle interior window condensation
You don’t have to settle for fogged-up or dripping windows because there are simple things you can do to deal with interior condensation.
- Get a moisture eliminator
Moisture-eliminating products are widely on sale, and will remove excess moisture from the air. Typically they contain crystals that absorb moisture before converting it into a saltwater solution. You hang the crystals up with a bucket or similar container on the ground beneath them to absorb moisture the crystals release.
- Switch on bathroom and kitchen extractor fans
If you remember to switch on an extractor fan every time you cook or take a bath or shower, it will remove moisture from the air. You will need to keep the fan running for around 20 minutes after cooking or washing. You can install fans that automatically cut off once the humidity levels are at an acceptable level. These may be worth your investment.
- Improve air circulation
If you have ceiling fans, don’t just use them in the summer when it’s hot. Using a fan in winter will help circulate the air indoors, rotating in a clockwise direction to push warm air from the ceiling towards the floor.
- Open the windows
Another thing you may associate more with warmer months, but if you open your windows regularly in winter it can release some of the warm, moist air trapped indoors.
- Raise the window temperature
The warmer your windows are, the more you can reduce condensation that gathers on them. Condensation occurs when warm air meets cold window surfaces, therefore the warmer the window, the less condensation there will be. You can raise the temperature inside, or use curtains, blinds or drapes.
- Install storm windows
Usually made of glass, or rigid or flexible plastic, you can fix storm windows either temporarily or permanently to your regular ones. As a form of secondary glazing, they work the same way as insulated glazing and are often an effective option for older properties. The space between the two windows helps retain window warmth, thereby reducing condensation on the interior windows.
- Weather strip your windows
Weather stripping helps prevent warm air from leaving a building by reducing drafts and heat loss. While storm windows can reduce interior window condensation, they may themselves attract it which is where weather stripping can help.
- DIY window insulation
A window insulation kit can be a cost-effective way of insulating your own windows. They consist of a transparent film you stick to the inside of the window, trapping air between the window and plastic film; or weather sealing strips (see above). Note: these are only effective on single-pane, rather than double or triple-glazed windows.
- If you use a humidifier turn it down
A humidifier makes the air in the home less dry. It can help treat dry skin, and make cold or flu symptoms feel less acute. However a humidifier also can increase condensation because it releases moisture into the air. Try turning it down.
- Get a dehumidifier
In contrast to a humidifier, a dehumidifier will remove moisture in your home and absorb condensation. Domestic dehumidifiers come in a range of models and sizes, from larger models to portable mini versions.
- Move your indoor plants
Any plants you have indoors will naturally release moisture into the air. If you have several houseplants by your windows, try moving some of them to reduce the concentration of moisture they release.
- Consider moving furniture
If you move your furniture at least 50mm away from external walls, it allows for air to circulate more freely. If you can, only place wardrobes against internal rather than external walls.
- Positive Input Ventilation system (PIV)
When you’ve tried some of these self-help solutions, and you’re still seeing an issue installing a PIV system could be the way to go. This unit is cited in your loft space and uses positive pressure to force the moisture laden air out of the property before it has chance to condense on surfaces.
Condensation in between windowpanes
This can occur in double-glazed windows and it is an indication that the seal has failed. The condensation becomes trapped between two panes and has nowhere to go.
If this is the case, the only way to solve the condensation problem is by replacing the glass.
If left untreated, it can eventually penetrate the wall below leading to problems such as black mould or even wet or dry rot.
Condensation gathered on the outside of your windows is a natural, meteorological phenomenon.
It doesn’t mean your windows are in any way defective and, with warmer weather, it will evaporate off the glass.
If you’ve got issues with condensation or damp, don’t ignore them.