When considering the perimeter sealing of windows, the inevitable priority is keeping the weather out and, due to increasing legislatory requirements for improving energy efficiency, reducing air leakage and thermal bridging.
Whilst there is some way to go to convince all installers of the benefits of insulating the perimeter gap for thermal benefits, the other way to add value to this joint is to improve the sound insulation of the installed window. In the same way that windows are manufactured to ever increasing thermal standards, by varying the glazing specification, improvements can be made to the acoustic performance, whether by triple glazing or a variation in pane thicknesses on double glazing. However, in much the same way as the energy performance of a window can be compromised by inadequate sealing methods, sound can pass through the gap around the frame and affect the acoustic performance of the window, irrespective of the determined dB reduction. With ever increasing population density and the need to build more housing in closer proximity to each other and to commercial, if not industrial buildings, noise pollution is likely to be of more concern.
There are user-friendly products available which will provide acoustic enhancement in the perimeter joint, including PU foams and impregnated foam tapes. Although such generic products are readily available, even greater benefits can be realised with the use of illbruck’s BBA accredited FM230 Pro Foam Window canister foam, providing a 60 dB reduction, significant flexibility with a movement accommodation factor >35%, and low post-expansion to facilitate easier application control. Additionally FM330 Pro Foam Airseal is also airtight and can be applied in conditions as low as -3°C.
Impregnated tapes, traditionally used as external weathertight perimeter seals, also provide acoustic benefits and when used in isolation will achieve around 40 dB sound reduction. The addition of a sealant to one exposed face of the tape will increase this further to 58 dB. Such figures are consistent with those of appropriately upgraded windows and therefore maximise the benefits of the complete installation.
In line with illbruck’s long standing and BBA accredited ‘i3 System’ for weather and airtightness, and thermal insulation, the additional value of acoustic insulation can be incorporated at no extra cost – ensuring the fulfilment of the three level sealing principle.
There is no doubt – it sounds an excellent idea!
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