Flanking Noise

There are several ways to soundproof a party wall from quite thin less efficient systems up to much thicker Studio Wall type systems that take up to 5.5 inches of room space. Whichever system is chosen, the benefits can be reduced if flanking noise is coming round the soundproofed wall. The most common flanking noise is usually in more modern lighter weight homes built with an external cavity system with lightweight internal block walls from either clinker block (breeze) or the lighter Thermalite blocks. Either of these will easily allow flanking noise either along or down them transmitting noise from other areas of the building and around any soundproofed walls, floors or ceilings.

Potential flanking noise should be identified and addressed before embarking on the soundproofing of walls, floors or ceilings and with external walls, the cavity should be infilled with blown mineral wool for best results. In addition, the inside of the wall should be lined with our Thin Wall System.

Flanking noise is also likely through a party wall beneath floor level and above the ceiling if both of these are timber suspended. For floors, the floorboards should be lifted next to the party wall and the void between the joists immediately adjacent to the party wall infilled with AMW Acoustic Mineral Wool. Two layers of SBM5 Soundproofing Mat can then either be fixed on top of the joists before replacing the floorboards or it can go on top of the floorboards before commencing installation of soundproofing to walls. The SBM5 is a recycled product that sometimes has an odour that is non-toxic but could be unwanted. To avoid this simply overlay with polythene that we can supply before covering the product.

Ceilings are a bit easier and if it is the ceiling beneath a loft, ensure that fibreglass type loft insulation is installed to the recommended depth required these days then add another layer of 15mm high density plasterboard to the underside of the existing plasterboard. Both floors and ceilings and external cavity walls must have additional soundproofing before installing sound insulation onto party walls to avoid flanking noise reducing the effectiveness.