- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 31 Jan 2017
The term ‘patent glazing’ refers to a non-load bearing, two-edge support cladding system. Its name relates to the number of patents that were taken out in the 19th and 20th centuries for different versions of the system.
Patent glazing bars provide continuous support along two edges of glazing infill panels, and are fixed back to the main structure of the building. This system supports its own weight, and provides resistance to wind and snow loading, but does not contribute to the stability of the primary structure of the building.
Patent glazing is a dry glazing system in which the patent glazing bars are drained and ventilated.
The earliest systems were typically manufactured from a steel section, covered with lead. However, the development of aluminium manufacturing during the second world war, and the clear advantage of the material in terms of weight and cost resulted in aluminium becoming the main manufacturing material in the 1950’s and 60’s.
Modern patent glazing systems are typically formed by aluminium T or box section patent glazing bars which provide continuous support along two edges of infill panels such as single or double glazing or composite panels. The glazing bars are fixed back to the main structure of the building.
Typically, aluminium patent glazing bars are available in lengths up to 7 or 8m, but beyond 3 to 6m, they generally need intermediate support, depending on their section size, anticipated loads and the weight of the infill panels.
Guidance for the design and installation of patent glazing is provided in BS 5516-1:2004 Patent glazing and sloping glazing for buildings. Code of practice for design and installation of sloping and vertical patent glazing.
Design and installation considerations might include:
- Maximum required span.
- Supporting structure.
- Access for maintenance.
- Requirement for opening roof lights to allow natural ventilation and smoke ventilation.
- Use of laminated glass to prevent glass falling in the event of breakage.
- Drainage (typically, a pitch of at least 15° is required to ensure rainwater run-off).
- Acoustic performance.
- Heat accumulation and shading.
- Wind, snow and maintenance loads.
- The pressure difference across the patent glazing.
 Find out more.
 Related articles on Designing Buildings Wiki
Featured articles and news
Do you know your Rococo from your De Stijl, your Gothic from your Post-modernist?
May outlines a new funding strategy for housing associations and says the 'stigma' of social housing needs to end.
RIBA launches a consultation on a new Plan of Work for Fire Safety.
This article offers some basic rules to follow when writing your next specification.
The iconic Mackintosh Building will definitely be rebuilt, board chairwoman confirms.
The machinery used to fashion stone has changed dramatically - and so have the products.
This type of pile provides support to the building, as well as acting as a heat source and a heat sink.
Why investors are adopting the SDGs and why civil engineering could be crucial for delivering them.
Read about all the winners from the London ceremony of CIAT's 2018 Architectural Technology Awards.
How do you find the right stone to conserve historic buildings?
Appointment agreements often include a ‘scope of services’ setting out the consultant's performance on a project.