How to Soundproof a Party Wall

Until now we have been discussing the type of noise that can be heard through party walls such as airborne and flanking noise and we have detailed how to address flanking noise.  Now we will talk about how to soundproof a party wall.  To obtain the best results when soundproofing any wall loss of space will be required and the more space that can be lost the better the soundproofing results will be.  Also, if the wall to be treated has a chimney breast the results are not going to be as good as a wall without a chimney breast.  This is because a chimney breast is directly linked to the other side of the wall and so will allow flanking noise ease of passage and flanking noise is noise that skirts round any effectively installed acoustic treatment.  It is possible to totally enclose the chimney breast behind an independent soundproofed wall then that would give good noise reducing results but rarely is this possible because too much space would be lost.

We will commence with describing the most efficient method of soundproofing a wall and we will assume it is a normal wall with no impediments although the same treatments can be applied to walls with a fireplace but for best results, the fireplace should be bricked up with high density blocks first.  The best treatment that will soundproof a wall is the independent stud wall and this will take up just under 6 inches (150mm) of room and is installed at least 25mm away from the wall to be soundproofed.  An acoustic infill of mineral wool is installed then the frame is clad with 30mm (2 x 15mm) of high density Acoustic Plasterboard.  For an enhanced result, SoundBlocker Quilt can be used instead of mineral wool and more information on this can be viewed on our web site.

If the amount of space required for the independent stud system cannot be spared then the next best thing is to fix the stud directly to the wall which will save at least 25mm.  But fixing anything less than 2 inches (50mm) deep stud will not be worthwhile.  The rest of the acoustic treatment remains as detailed above with the exception of fixing the plasterboard.  When stud is directly fixed to walls it is essential the acoustic plasterboard is decoupled to reduce flanking noise and this is done by screwing Resilient Bars across the stud frame then screwing the plasterboard to the bars.  As the name suggests, the Resilient Bars then act as a flexible decoupler that isolates the plasterboard from the frame and wall making the sound insulation of the wall more efficient but not as efficient as an independent stud system.

If even the direct fixed stud system is losing too much space the next system that can be used is the M20AD system referred to in an earlier article and the M20AD system will take up no more than 2 inches (50mm) of space.  This system breaks away from mechanical fixings and comprises three layers that are glued.  The first layer is just over ¾ inch (20mm) thick and this is the M20AD sound insulation that is a high density recycled rubber sound insulation that is bonded to the wall using our aerosol contact adhesive.  Once the M20AD has been securely fixed, two layers of 15mm high density acoustic plasterboard is then glued on top using the same adhesive.  More information on the M20AD system along with comprehensive installation instructions can also be viewed on our web site.

A more recent solution and the thinnest that can be installed so by definition, the least efficient soundproofing system is QuietPanel at 27.5mm thick.  The QuietPanel system was introduced due to popular demand because in many cases a noise reducing system for party walls is required but space is limited due to the close proximity of windows or doors so the QuietPanel system was introduced for those instances for those with limited space and know this is the least efficient system to soundproof a wall but realise that something is better than nothing.  QuietPanels are supplied as a one part application and are simply screwed to any masonry wall using screws and plugs.

Now you have been given an insight into what is involved when considering upgrading the soundproofing of a party wall and I hope this article and the previous three have proved useful.