Secondary glazing noise and sound insulation properties





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Mobile : 07875 369 855



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North London Secondary Glazing
Unit 4
Noke Lane Business Centre
Noke Lane
St. Albans, Herts



Secondary glazing noise and sound insulation properties



Secondary Glazing Products


Find out more information about the different types of secondary glazing we can provide



Tilt In Vertical Sliding Secondary Glazing



Vertical sliding secondary glazing has been designed especially for secondary glazing sash windows. Secondary glazing for sash windows mirrors the primary sash window - consisting of two secondary sashes, one above the other, securely retained in their own outer frame. The balanced vertical sliders are supported by robust spiral spring balances for added ease of opening & closing. The spiral balance system supports the weight of the secondary sashes & makes this unit suitable for larger sash windows.


The tilt-In facility allows each secondary sash to be independently released from the outer frame & pivoted inwards through almost 180° - thus presenting the other side of the glass for easy cleaning.


Sight lines of the secondary double glazing for sash windows match a traditional sash window and the secondary sashes are easily moved up & down with the weight supported by the balance system. Suitable for Listed Building sash windows, Conservation Areas & all other properties with sash windows.



tilt in unit glazing  high quality tilt in secondary glazing tiltin  silders tilt in glazing panels

Click to enlarge





Vertical sliding secondary glazing units can be used for a number of different applications.



  • over traditional sash windows of all types, sizes and ages
  • in combination with other secondary windows in sash window bays
  • for arched sash windows



  • for shaped sash windows
  • in combination with other secondary window units where sash windows are next to doors
  • over stained glass for insulation and protection


Sizes, Guidance & Restrictions


4mm clear toughened float glass
6mm clear toughened float glass
with 6.4mm clear laminated glass

1500mm width x 3000mm height
1400mm width x 2700mm height
1400mm width x 2700mm height


You can contact NLSG any time to find out more about our up-rated specifications to accommodate larger size secondary glazed windows subject to safety considerations such as the weight of the secondary sash panels for safe handling, the specific application and any potential detrimental effect on the units' performance.


To enable cleaning - the balanced tilt-in secondary sash window has panels which can be tilted into the room to allow access to the non-room side of the glass for easy cleaning and maintenance of both the secondary & primary windows. This product is ideal for installations where the gap between the main window & the new secondary window is limited.



Vertical Sliding Secondary Glazing Windows - Standard Product Range


  • black gaskets
  • 4mm clear float glass
  • ptilt-in facility
  • direct fixing subframe - 21mm x 45mm
  • white frames & sections
  • white interlock fitch catch
  • integral timber subframe
  • reveal fixing subframe - 21mm x 62mm



Manufacturing Options


  • Van Dyke Brown powder coated finish
  • silver anodised finish
  • woodgrain effect powder coated finish
  • standard fitch catch on central interlock sections (silver or gold)
  • locking fitch catch on central interlock sections (white, silver or gold)
  • Chubb Locks
  • restricted opening locks
  • standard vent - for adjustable trickle ventilation 4000mm² requires additional 21mm sub frame at the head (total 42mm)
  • acoustic vent with integral fly-screen - for adjustable trickle ventilation 1600mm² requires additional 21mm sub frame at the head (total 42mm) - reveal fix only, requires internal clearance for the baffle - supplied complete with 60mm pre-routed cover architrave
  • integral timber subframe for a bay window - angled one or both sides
  • chamfered timber subframe for square bay windows for optimum sight lines
  • without subframe
  • white gaskets
  • 6 standard RAL colours - pure white, ivory, cream, magnolia, grey, jet black
  • any non-standard RAL colour finish
  • glazing - from 4mm up to 7.5mm - for thermal insulation or sound insulation
  • shaped units - curved, semi-circular, arched or Gothic heads



Contact the NLSG team to find out how we can help you.