Waking up to windows obscured by condensation is a common and frustrating winter problem for many households across the UK. This moisture buildup not only blocks your view but can also lead to more serious issues like black mould if left unaddressed.
The 'Magic' Household Solution
One homeowner, tired of the daily chore of wiping down his windows, sought advice on the Money Saving Expert forum. The response that stood out suggested a surprisingly simple and effective solution: applying a thin layer of shaving foam to the glass. According to the tip, shared on 20 November 2025, you should apply the foam evenly with a cloth, using just enough to create a thin coating, and then rub it in until the window becomes clear, leaving only a slight smeary film.
The user reported that this method keeps their bathroom mirrors and car windows condensation-free for four to six weeks. They were also careful to specify that shaving gel should not be used as a substitute.
Why Does Shaving Foam Work?
While it might sound unusual, there is a scientific reason behind this clever hack. Shaving foam contains surfactants, which work by reducing the surface tension on the glass. This action prevents tiny water droplets from forming, effectively stopping the condensation in its tracks. This is a trick well-known among motorists who use it to prevent their car windows from misting up on cold mornings.
The Importance of Ventilation for a Long-Term Fix
Although the shaving foam hack provides an excellent temporary defence against condensation, experts and forum users alike stress that it is not a permanent cure. The key to eliminating window condensation for good lies in controlling the humidity levels within your home.
Condensation and mould thrive in damp, chilly environments, so improving ventilation is crucial. Effective strategies include opening windows during the day when temperatures are milder and always using an extractor fan in the kitchen while cooking and in the bathroom after a shower.
As one commenter on the forum succinctly put it, "Heat and ventilation are the key." They also suggested that using a dehumidifier can be highly effective, especially if you dry laundry indoors during the winter months. If running a dehumidifier is too costly, simply having a window ajar near your clothes horse can help significantly reduce moisture in the air.
Another user emphasised the need to create less water vapour and effectively remove what you do produce. This means ensuring extractor fans in bathrooms run for about 20 minutes after a bath or shower, using lids on pots when cooking, and avoiding drying washing indoors unless you are using a vented tumble dryer.
