Horizontal sliding secondary glazing

Horizontal sliding windows can be produced with one or more sliding panels.

The sashes slide within the frame, allowing easy access to the outer windows without interfering with curtains, blinds or ceiling bulkheads.

Units can be linked with coupling sections allowing both large and ribbon windows to be successfully treated.

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.

Panel Size

Using large panels can be quite cost effective since it reduces the amount of framing material but there are a number of factors that should be taken into account.

• The ability of the end user to deal with the weights involved. A panel 1000mm x 2100mm in 6mm glass will weigh over 30Kg and a reasonable force will be needed to move it
• The cill height - large or tall windows set on high cills will be more difficult to operate.
• The height:width ratio for sliding panels. Where this exceeds 4:1 the panels are more likely to suffer from racking - the tendency of a panel to bind within the headframe. Two individual windows coupled by a transom should be used.
• Frequency of use - an air-conditioned or secure environment will require panels to be operated infrequently, possibly only for cleaning and maintenance, in which case larger panels may be acceptable.
• Responsibility for removal and cleaning. Will this be the end user or a cleaning contractor? A manual handling risk assessment must be completed

Number of Panels

Horizontal sliding units are generally available in 2, 3 or 4 panel versions but additional panels can be considered in special circumstances. It should be noted however that specifying multiple panels:

• May lead to reduced sealing efficiency since it will be difficult to fully close all the panels.
• May reduce the options for partition points in commercial buildings

The 3 panel unit is available in three versions - one in which the centre sash normally remains static and one in which it slides independently. The choice will depend upon access requirements to the outer window. Finally there is a triple track version (Series 10) that allows 2/3rds access to the outer window.

Window Coupling

A range of aluminium coupling mullion / transom sections are available to link windows both vertically (mullion) and horizontally (transom). Long span transoms will require additional supports in the form of vertical hangers or full height box sections set behind the interlock points of the window.

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.