DIY secondary glazing – does it really work?

6th Feb 2020
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If you’re a homeowner in search of new ways to improve the performance of your windows, chances are you’ve stumbled across DIY secondary glazing kits. For those who don’t know, secondary glazing involves fitting a single glazed window to the inside of an existing window. When professionally fitted, it allows a window to retain more heat and blocks more outside noise from coming in. It also reduces condensation and improves security.

DIY kits claim that they are able to provide the benefits that you would expect from a professional job too. But do they really work? Let’s take a closer look and find out:

Insulating film DIY secondary glazing

Insulating film DIY secondary glazing is cheap and easy to fit. It involves sticking a transparent film over the glass area of an existing window. This creates an insulating air cushion and a layer of moisture-proofing. This improves heat retention and reduces condensation respectively.Secondary 2

However, as it only covers the glass area, its heat retention is pretty limited. As a thin layer of film, it will also block out no outside noise and provide no boost to window security.

Most importantly, this type of secondary glazing is only intended for temporary use too. You fit it during the winter and then by late spring, you’ll have to remove it and buy more the next time you need it. When you consider that secondary glazing from us comes with a 10-year guarantee but is able to last longer than this, there really is no contest between them in this respect.

Magnetic secondary glazing that has a plastic/acrylic panel

This type of DIY secondary glazing involves the use of a plastic glazing panel that is held in place by either magnetic or self-adhesive strips. There are also options that involve you screwing the framework into place. However, because of the labour intensity of the last method, you’re better off paying a professional to fit it for you.
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Plastic is a naturally insulating material, meaning this type of DIY glazing offers considerable heat retention, draught-proofing and condensation reduction. However, unlike the low-e glass that we use for our secondary glazing, it does not have a special layer that reflects heat back into the room.

There is also the issue of overheating with these systems. The cavity between the secondary glazing and existing window can become very hot after extensive sunlight exposure. This can damage the acrylic. It can also cause the adhesive strips to become dislodged. However, a professional job is screwed in and the overheating issue is not so drastic with glass.

Some varieties of this DIY secondary glazing also claim that they can reduce outside noise by about half too. However, our secondary glazing can reduce a noise of 39dB by an estimated 65%. So, acrylic versions are not as effective in this regard.

High-quality secondary glazing from Sheerwater Glass

DIY secondary glazing is cheaper, but you don’t get the same performance levels that you get with a professional installation. A testament to the old adage of ‘you get what you pay for’ if you’d like to have secondary glazing fitted to your home, get in touch with Sheerwater Glass on 01932 344 415 or contact us online. For more information on secondary glazing, check out our secondary glazing consumer guide.