Fixed secondary glazing

Fixed secondary glazing panels are generally used side or over lights in combination with other windows and are also extensively used to treat curved windows.

Because it is fixed, this option should never be used where the window is required access for escape purposes.

The range includes:

Note 1 - Series 20 and Series 60 have a maximum area based on the spring balance capacity. Windows cannot be constructed with both dimensions maximized. Refer to Soundproofyourhome for advice for advice.

Fixed panels are generally used in combination with other window styles to provide side lights or over lights particular in the treatment of arched windows. They are also used within partition walls as observation windows for laboratories, control rooms, clean rooms and recording studios.

Series 45 - Very slim sections with minimal dust ledge.

Series 40 - Heavy duty system accepting single glass up to 12mm glass or 24mm sealed glass units for optimum thermal insulation.

Series 50 - Security rated fixed system suitable for observation windows and can be linked to Series 50 hinged casement.

Series 55 - Security rated fixed system with a permanently fitted subframe incorporating a demountable sash to allow occasional access for cleaning or maintenance. It will provide security against outside threats and the absence of a ligature point makes it appropriate for use in institutions.

General guidance

• They must never be installed across a window requiring access for escape purposes.
• When used in combination with other opening windows there should be a sufficient cavity between the windows to allow access for cleaning.
• Where a window is treated with a fixed panel or series of fixed panels ventilation holes may need to be drilled to the outside to permit air flow and combat condensation.

Improve the acoustic performance of your windows

At best, a typical sealed unit constructed from two panes of 4mm glass with a 12mm cavity will provide a sound insulation level of around 30 dB. Adding secondary glazing to this typical unit, set an air space of 100mm or more, will provide overall sound insulation of 37 to 40 dB. Because noise level is measured in decibels (dB) and the decibel scale is logarithmic, a 10 dB increase will approximate to a perceived doubling of the noise level. Alternatively a reduction of 10 dB will lower the level of perceived “noise” by 50%.

Secondary glazing systems are already widely used in the commercial and leisure sectors, as well as in all sorts of health, education and public buildings.

When noise is a problem, a double window system will provide noticeably better soundproofing than a single window, even if this is fitted with double glazed units.

They are also uniquely suitable for listed and heritage buildings.

How secondary glazing works

The cavity makes the difference

The gap or cavity between an existing primary window and the secondary unit makes a significant difference to the level of noise insulation. Unlike sealed units where the two pieces of glass are rigidly coupled together, the primary and secondary window acts as independent barriers to noise transmission. As a general rule, the greater the cavity (a minimum of 100mm is recommended) the greater the sound damping effect of the combined window.

Minimise the gap

Gaps around window frames, although minute, still allow the passage of airborne sound that can reduce noise insulation levels by as much as 10 dB. Our secondary glazing units are tailor made to the aperture and come with high performance seals to sound shield the whole window opening and minimise sound leakage.

Multiple glass options

Having the ability to select for purpose from a wide range of glass types ensures optimum performance. For example fitting inner and outer glass with different mass avoids the phenomenon of sympathetic resonance which increases noise transmission at higher frequencies. The greater mass of thick glass improves acoustic performance, particularly at lower frequencies. Acoustic laminate glass has a special interlayer that helps improve high frequency performance – something very well suited to dealing with aircraft noise.

Acoustic liners

Acoustic absorbent lining materials can be fixed between the window frames raising insulation levels by 1 – 3 dB, most effective at higher frequencies.

Professional Secondary Glazing Installation Service available

Surveying, measuring, transporting and fitting secondary glazing is a skilled business requiring experience, product knowledge and specialist tools.

For these reasons we strongly advise that customers use only our professional secondary installation service which is available for projects across the UK. Tackling secondary glazing on a DIY basis is never recommended.

Our experienced professionals and tradesmen thoroughly understand acoustic secondary glazing applications, the materials used and how measure and to fit them quickly and correctly.

The result for the customer is a cost effective service and peace of mind about the acoustic integrity of the secondary glazing project. Contact us today for a free quotation or to arrange a site visit.

Soundproofyourhome is the domestic market operations division of JCW Acoustic Supplies Ltd, the UK’s leading manufacturer and distributor of soundproofing, sound insulation and sound absorbing products.

Sound advice from Soundproofyourhome:

Contact us today and tell us more about the noise problems you are experiencing. Our friendly, helpful advisors will offer you the most appropriate acoustic solutions available to meet your acoustic needs and budget from our comprehensive range.

We believe talking about your situation and offering sound advice based on our vast experience in the acoustics business is a more reliable way of solving your noise problem than simply taking your order or selling “off the screen”, as some companies do.

And if you are in any doubt about issues associated with soundproofing, like weight of materials, structural strength or meeting Building Regulations, then please talk to us – we’ll be happy to help.