Types of glass make a difference on partition acoustics It’s true to say that a number of different factors come into play when specifying acoustic glass partitions. Carrying out acoustic testing with specific methods show your test certificate is credible. In addition, it demonstrates how the acoustic performance of glass partitions are sometimes affected by factors on site. It is also important to consider the required glass type and thickness in order to achieve the desired acoustic rating. For example, the Optima 117 single glazed system has been tested using a variety of glass types and thicknesses. Consequently, achieving a range of acoustic ratings, such as: 12mm toughened glass in single glazed multi-module screen Rw33dB Test ref: 542-434 12.8mm acoustic laminated glass in single glazed multi-module screen Rw38dB Test ref: 542-432 Specify double glazed for higher acoustic ratings. The Revolution 100 double glazed system, for example, can accommodate a range of glass types and thicknesses, such as: 12mm toughened glass + 12.8mm acoustic laminated glass Rw48dB Test ref: 2151-1845 2 x 12.8mm acoustic laminated glass Rw51dB Test ref: 2151-1848 When selecting glass thickness that best suits the required acoustic performance, consideration to how you’re applying the glass is paramount. At this point, it becomes important to understand the difference between the various glass types that we offer. Most importantly, when it’s most appropriate to use them. All glass used in our glazing systems is class A safety glass as defined in BS6206. However, there are a number of glass types that fall into this category; some more appropriate than others in certain scenarios. Which types of glass should I use? Toughened glass Standard: BS EN 12150 Annealed glass that has been thermally treated to give it much greater impact resistance: typically, seven times greater. Toughened glass satisfies BS6206 in that it breaks safely, shattering into equally sized ‘dice’. Drilling or clamping glass is only recommended with Toughened, for example, when used for accommodating door furniture. It is important to note that the toughening process stimulates Nickel Sulphide (NiS), known as ‘inclusions’, which occurs naturally in float glass. The presence of these inclusions can, over time, although very rare, induce a spontaneous fracture of a toughened glass panel. Whilst all glass manufacturers and processors take all practicable steps to ensure glass is inclusion-free, it is not possible to guarantee the absence of nickel sulphide inclusions. Heat soaked toughened glass Standard: BS EN 14179 To significantly reduce the risk of NiS induced spontaneous failure, toughened glass panels are sometimes subjected to an additional process known as heat soak testing. Although not providing a 100% guarantee, this process can reveal the presence of NiS inclusions. It is a destructive test, designed to break any panel that is at risk. In order to ensure complete customer confidence in the safety of glass, it is company policy to heat soak all toughened glass. Laminated Glass Standard: BS EN ISO 12543 Producing Laminated glass requires bonding two layers of annealed glass either side of a PolyVinyl Butyral (PVB) Interlayer. With the intention of categorising our product as a class A safety glass, the PVB interlayer must be not less than 0.76mm thick and achieve safe breakage by the interlayer holding the fractured panel together. When not needing to drill or cut the glass, we recommend the use of laminated glass for partitions. Acoustic Laminated Glass Standard: BS EN ISO 12543 We produce Acoustic laminated glass the same way we produce regular laminated glass. However, it utilises a specially formulated acoustic PVB interlayer to achieve significantly better acoustic properties. Toughened Laminated Glass Standards: BS EN 12150 (Toughened) and BS EN 12543 (Laminated) This type of glass combines the benefits of both toughened and laminated glass and would typically involve a 1.5mm PVB interlayer. Because it has the additional benefit of lamination, the glass would not normally require the additional process of heat soaking. Toughened laminate glass, commonly specified for glass screens adjacent to a significant change in level (e.g. an atrium) and where there is the potential for significant crowd loading as defined in BS 6180 and BS 6399. Annealed Glass (unprocessed float glass) We do not use Annealed glass in its basic, unprocessed form due to the fact that it is not categorised as safety glass. Choosing a Glass Type for Partitions based on Application – Some Examples Many architects choose to specify laminated glass in partitions, due to the safe nature of breakage and the added flexibility of being able to achieve different levels of sound control, privacy, security, and decorative effects by varying the thickness and type of interlayer used. On the CMS project, for example, a single glazed system with a high acoustic rating was required, so 12.8mm thick acoustic laminated glass was the perfect solution. Full height glass partitions protect from a level drop which acts as guarding. This scenario occurred at JP Morgan, where our Revolution double glazed system was specified. We installed a combination of 17.5mm thick toughened laminated glass and 12.8mm laminated glass for enhanced safety and to ensure that the glass would withstand the appropriate design loads. Summary There are a number of different glass types and thicknesses that are typically used when specifying glass partitions, to suit both the desired acoustic performance and the glass application. Not sure which glass type would best suit your project? Speak to our technical experts.