Secondary Glazing – Sound and heat insulation

Secondary Glazing Sound Insulation

The gap between the original window and the new secondary glazing is one of the most important things to consider regarding sound insulation. The most common size pane of glass in the original household glazing would typically be around 4mm, unless the property is pre 20th century, then it could be 3mm.

  • So if the original house glazing is 4mm and the secondary glazing is 4mm, the gap would need to be around 150mm between the original window and the new secondary glazing for optimal sound insulation.
  • With 6mm glass in the secondary glazing this gap could be reduced to 100mm.
  • If the reveal (or window cill depth) cant accommodate a 100mm gap then laminate or acoustic glass like Stadip should be considered for maximum sound insulation.
  • In general terms the larger the gap the better the sound insulation.

Stadip Acoustic glass for the best performance 

Stadip Silence glass is a laminated product from Saint-Gobain. Laminated glass is a sandwich made of one piece of plastic Poly Vinyl Butyral (PVB) between two or more glasses. The PVB in Stadip glass is a special acoustic interlayer – PVB Silence®. This layer acts like a dampening core between the two panes of glass. It prevents vibration, eliminating the problem of the critical frequency and thus the acoustic peaks at high frequencies. Download our free Stadip Silence brochure.

To what extent does secondary glazing reduce sound pollution in the home?

Secondary glazing correctly specified and installed will acoustically outperform all other types of glazing, including new windows and even triple glazed ones. Installing good secondary glazing really is the best option eah and every time. To achieve up to an 80% acoustic performance KJM recommend the specification of acoustic glass and an air cavity no less than 150mm – 200mm glass to glass

The benefits of secondary glazing:

  • Secondary glazing is one of the best ways to reduce noise and sound proof your windows, it can reduce external noise by around 75%. This can be enhanced further by specifying either Laminate glass or Stadip Acoustic Glass.
  • Draught Proofing is the other most common reason to install secondary glazing.
  • Low E Pilkington K glass (option)
  • Our secondary glazed system can even incorporate fly-screens
  • Extra security
  • Retains the exterior look/character of the property

Secondary Glazing Options

  • Horizontal slider
  • Side Hinged
  • Vertical Sliding
  • Fixed Units/Lift Out

Butt Hinged

Butt Hinged secondary glazing comes as either a single or double panelled unit. The butt hinges give a large clear opening which allows for easy maintenance and cleaning. The clear opening may also be of benefit where the window is a means of escape. Our butt hinged units are made from slim and strong aluminium. The butt hinges allow for the secondary unit to open fully. These butt hinged units are only side hung but our friction hinged secondary glazing is available in both top and side hung styles.

Lift Out

The secondary glazing standard lift-out is a removable secondary glazing panel within its own outer frame that is fixed to the face or reveal of the existing primary window. The integral finger lift bar at the bottom of the panel allows it to be lifted up into the top of the secondary window outer frame and then swung inwards to facilitate removal.

Tilt Back Balanced Vertical Sliding

Designed to match existing sash windows, our Tilt Back balanced vertical sliding secondary glazing is one of our most popular secondary glazing products. They reduce noise, cut heat loss, are easy to fit and are very affordable. Our tilt back balanced vertical slider is made from slim and strong aluminium. The panels are balanced – reducing the effort required to slide the panels up and down. The balances also mean the panels remain in position at whatever height you leave them. By operating finger latches the panels can be tilted inwards for easy cleaning.

Horizontal Sliding

Our horizontal sliding secondary glazing is extremely versatile, slides smoothly and is available with two to five panels. Horizontal sliders are perfect for sound and thermal insulation for casement windows, hinged windows, or any window that has vertical bars. Panels slide within the frame allowing easy access to the existing outer windows, providing ventilation without interfering with curtains or blinds.