How to Stop Condensation With Window Film

Updated on October 24, 2016

Causes Of Condensation On Home Windows

The main causes of condensation on home windows is excess moisture in the air, poor ventilation, poor insulation, poor heating or a combination of all four.

The best way to solve this problem is to fully insulate your home, turn up the heating and fit proper ventilation. In practise this isn't always possible, practical or cost effective. And even less so if you live in a rented property.

One of the best options is to insulate windows with window film insulation as it is quick, cheap and effective.

Window Insulation Film

Window insulation film is a thin transparent plastic material which is fixed around the window frame to create an additional later of insulation almost like double glazing which prevents heat loss through glass windows. The idea is very simple, affordable, yet very effective and easy to install. It is especially useful for single glazed, old, large or sash windows. The best way to heat a house is to reduce heat loss within the house, most of the heat is lost through glass windows, the best way to prevent this is by having double glazing fitted but if you live in a rented property this is not always and option. By using window film you will dramatically reduce the amount of heat lost and in turn reduce heating costs. The film looks like Saran Wrap (plastic kitchen film used to cover food stuffs) but is thicker and not stretchy. It is specially designed to act as an insulator.

Window Film Installation Process

The process is very simple but you will need to follow a few simple rules to ensure the best results and gain the most benefits. The window film is supplied with double sided sticky tape which is affixed around the window frame.

  • Firstly you must make sure the window frame which you are going to fix the film to is in good condition without any loose or flaking paint. If the paint is flaking or loose the surface should be sanded down and repainted to ensure a non porous surface.
  • The window frame should be cleaned with water and washing up liquid solution to remove any oil and grease which may prevent the tape from sticking and left to dry.
  • Now the window is ready for the installation of the film. The window film should be roughly cut a little larger than the window frame.
  • You should ensure the glass is as dry and free from moisture & condensation as possible using a hair dryer. It is best done in the daytime when the light is good and the weather is warm so condensation does not collect on the window.
  • One piece of doubled sided sticky tape is then stuck along one length of the frame and the other side of the tape removed. The next length of tape should be applied overlapping at the corner, this process should then be repeated until all four sides of the window frame are covered. This method will ensure there are no gaps and an airtight seal will be created.
  • Then the precut piece of window film should be stuck around the frame, stretching it to try to make sure it is as tight as possible but a few small creases and wrinkles are expected.
  • Once the film is in place you use a hair dryer, starting from the edges working towards the center to remove the creases & wrinkles from the film until it almost becomes invisible.
  • Once you are happy with the result use a sharp knife to remove any excess film from around the edges.
  • Turn the thermostat down and enjoy!

Here you can see the bottom half of the window is covered with window film and the top half is not.  You can clearly see how the window film has improved the insulation and reduced condensation.
Here you can see the bottom half of the window is covered with window film and the top half is not. You can clearly see how the window film has improved the insulation and reduced condensation. | Source

Double or Even Triple Insulation

The window film can be applied around the frame which holds the pane and then an additional layer can be placed over the outer window frame effectively creating a triple layer of insulation. Each layer traps air which acts as a very cheap but very cost effective method of insulation. Window film can be used not just on windows but on doors with glass panels or window frames which are in poor condition which allow drafts in. Once the windows have been covered with film the room will be noticeably warmer and condensation greatly reduced.

Preparation Is Everything

The majority of people who have used this product are very happy with the results. However some people are not satisfied and this is mainly due to poor preparation, as mentioned above you must ensure the window frame is in a good and clean (free from oil and grease) condition to make sure the tape sticks and stays stuck to the frame all winter. Window latches and locks can be difficult to affix the tape to but I usually use blue tack over the locks and latches to create a smooth surface and create that all important airtight seal.

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Questions & Answers


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      • SpaceShanty profile image

        SpaceShanty 4 years ago from United Kingdom

        Thanks for your comment WriterJanis!

      • WriterJanis profile image

        Janis 4 years ago from California

        Great step by step instructions.