Unwanted noise

Noel Larkin answers a readers question in the Irish Times Property Clinic, published 10th March 2016.

I live on a busy cut through road. Our windows are quite old so we tend to have a lot of condensation in colder months and they do little to block out noise. We have received four quotes for double glazed windows, with three out of the four saying that the double glazed windows will reduce the noise, and the other saying it would have little impact.

We are concerned about paying for new windows but still being able to hear the heavy traffic noise, which is a real disturbance to us. What should we do? Also are Liniar okay? We’ve heard ofDuraflex and Rehau but one of the companies said they useLiniar.

A Double glazing has long been associated with reducing levels of sound. Traffic noise is probably the greatest nuisance in terms of people’s quiet enjoyment of their homes. In your case, it is causing annoyance and clearly there is an issue with significant heat loss, with subsequent condensation. You want to kill two birds with one stone and solve both the condensation and noise issues in one go.

Sound travels through air and air gaps around windows can be an issue. The way your house is built will also have an impact in terms of sound entering your home. It is important therefore to look holistically at your house and to take advice with regard to potential solutions.

The presence of permanent vents to habitable rooms, vents to underfloor voids, where suspended timber floors are used, roofs over bay windows and the like, can all contribute to sound ingress. The provision of new windows therefore may not fully resolve your issue.

Traffic noise generally leads to vibration in buildings. This transmits outside noises to the inside. The only way to reduce this is to introduce a method to reduce or interrupt vibration. The use of solid materials is fine for walls, but at windows, a solution is not as clear cut. Reverberation of glass can transmit sound to the point where noise internally is exactly the same as that experienced on the outside of a building.

If your new double glazing is not designed specifically to deal with a reduction in sound transmission, then sound will penetrate. The outer glass will reverberate and simply transfer the sound from one pane to the other and then, to the inside of the property.

However, with the study of sound waves it has been established that reverberation takes place more easily in similar materials. Therefore, if glass panes of varying thicknesses are used for the inner and outer panes in double glazed units, sound transmission will be reduced. Depending on the gas used to fill the void between both panes of glass, further sound reduction can be achieved.

The different companies you mentioned are manufacturers of uPVC windows. Without looking at their particular products, it is difficult to advise you as to which would suit best in your particular case. The main variation in terms of the supplier of the window frames is the profile/appearance of the window. In your case, the glazing is of more significance in terms of dealing with the sound transmission issue.

You should obtain a detailed specification from the companies providing you with quotations and have these reviewed by a building surveyor.

Noel Larkin is a chartered building surveyor and member of the Society of Chartered Surveyors Ireland, scsi.ie