Guide to Line Loads for Commercial Glazing

What is a line load for glazing?

A line load is a horizontal force at the top of the Balustrade and are also present in floor to ceiling windows – it is the horizontal force applied to the glazing to mimic the force of a person leaning on it. It is a consideration needed for walls, facades and glass balustrades. Intended to Mimic the force of a person leaning on the top of the balustrade. It is measured in KN/m and loading requirements for all glazing is depending of the capacity of the load under stress  

When are line loads important?  sanblasted frameless glass balustrades around a rooftop terrace scaled

There are many reasons for the importance of line loads in commercial glazing, however the most important reason for line loads is for safety regulations. This is because if someone should fall against the balustrade or a large force applied to it, it will not break and thus the public are not endangered.  


Glass balustrades are subject to a line load test which is a horizontal force applied intended to mimic a person leaning against it.

Building Regulations Approved Document K Section 3  protection from falling – line loads for glass balustrades in non-residential projects. 

The importance of line loads in commercial glazing is something that is expressed in Approved Document K. A set of regulations that ensure protection from falling, collision and impact. This series of documents provide practical guidance for those responsible for building work to ensure compliance with a variety of building standards to mitigate the likelihood of falling collision and impact.  

Due to the vast amounts of detail covered in approved Documents the set of regulations which are applicable for Line loads in commercial glazing are listed in section 3 Requirement K4 : protection against impact with glazing which outlines 6 stringent frameworks to minimise risk these include ; 


  • Measures to limit the risk of cutting and piercing injuries by the use of glazing that is reasonably safe, such that, If breakage did occur, any particles would be relatively harmless
  • Use of glazing sufficiently robust to ensure that the risk of breakage is low. 
  • Steps are taken to limit the risk of contact with the glazing.  

Safe breakage-  

  • In an impact test a breakage is safe and creates one of the following  
  • a small clear opening only, with detached particles no larger than the specified maximum size  
  • commercial offices with frameless glass balustradesdisintegration, with small, detached particles.  
  • broken glazing in separate pieces that are not sharp or pointed.  


  • Some glazing materials such as annealed glass gain strength through thickness; others such as polycarbonates or glass blocks are inherently strong 
  • The maximum dimensions for annealed glass of different thicknesses for use in large areas forming fronts to shops, showrooms, offices, factories and public buildings  

Glazing in Small panes-

  • In the context of this approved document, a small pane is an isolated pane or one of a number of panes held in glazing bars. 
  • Small panes should be provided in accordance with all of the following- 
  • In a small, annealed glass pane, use glass with a minimum 6mm nominal thickness 
  • In traditional leaded or copper lights, when fire resistance is not important, you may use 4mm glass. 

Permanent Screen protection- 

  • The permanent screen should comply with all of the following 
  • Prevent a sphere of 75mm from coming into contact with the glazing.
  • Be robust. 
  • If it protects glazing installed to help prevent people from falling, be difficult to climb. 

 Overall Line Loads establish themselves as a vital part of construction in Glazing. There consideration is Vital in Any Commercial Glazing solution, with it mitigating the Likelihood of safety hazards occurring thanks to ensuring the correct safety standards are met.  At IQ we Champion meeting the correct standards of performance required for glazing solutions to ensure optimal operation and Ensured Safety. If you have a commercial project that requires abiding to a stringent set of regulations contact us at

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Shannon Normoyle

As one of the Senior Marketing Executives, Shannon oversees the website and SEO management for IQ and can often be found working on SEO strategies or writing content for the websites. 

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