More on noise through a party wall and flanking noise

As I have mentioned before, noise though party walls takes different forms and those which are loud are anti-social noise that can only be addressed by outside authorities.  From now on we will talk about normal levels of noise such as talking that should not be heard during the daytime.  Assuming it is normal levels of noise that have to be addressed we have to also think about flanking noise.  Now flanking noise is noise that skirts around the party wall via the hollow sections beneath floorboards and also above the ceiling.  With pre-war buildings these are usually the only areas that can be treated to reduce flanking noise transmission because there are no cavities in the structural walls that would otherwise allow the free transmission of noise.  Chimney breasts and internal attached walls are other areas that can allow flanking noise but are usually impractical to effectively soundproof.

Firstly we will deal with pre-war houses and flats that usually have solid structural walls that do not require additional treatment.  This means the floor and ceiling and these should be treated before doing anything with the party wall to reduce flanking noise in those areas.  With the floor it will be necessary to lift the floorboards closest to the party wall and insert between the joists immediately adjacent to the wall Acoustic Mineral Wool.  If the joists are supported by the party wall then install enough to cover 1200mm from the wall and along the space between the joists.  If, on the other hand, the joists are parallel to the wall, then simply insert the acoustic mineral wool in the space between the first two set of joists then replace the floorboards and screw them down.  Once refitted, overlay with 2mm of SBM5 soundproofing mat that will seal up the joints of the floorboards.

The same infill treatment using acoustic mineral wool should be carried out on the ceiling but if it is a top floor bedroom ceiling there may already be thermal insulation in between the joists and it is not wise to remove it.  The ceiling itself can be upgraded with an additional layer of 15mm high density acoustic plasterboard that will add mass and therefore improve the sound blocking performance of the ceiling.  Now the floor and ceiling have been acoustically treated we can look at what can be done to soundproof the party wall and I will cover this in my next article.  In the meantime if you require any further information on how to soundproof a party wall go to our web page via this link  soundproof a party wall.

This article is just an introduction to flanking  noise that can skirt round  party walls.  More about how to soundproof a party wall will be published in the near future.  If you want to see more about how we can help soundproof a home go to our web site via this link.  Soundproof a home.