Insulation for Masonry Cavity Separating Wall

2020 ISOVER Party wall Masonry

For illustrative purposes only

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The primary purpose of a separating (Party) wall is to provide acoustic separation for airborne sound between two adjacent dwellings, thereby improving the acoustic comfort of those living within both dwellings. The minimum permitted acoustic specifications are defined by Approved Document E (England & Wales) and Section 5 (Scotland), although it is often recommended to improve on this where possible.

One of the methods to demonstrate achieving this is to use Robust Details, alternatively an acoustician can be tasked with verifying the design of a separating wall.

The insulation of choice for masonry cavity separating (Party) walls is typically a glass mineral wool (GMW) roll or slab. Isover RD Party Wall Roll can be installed as part of the separating (Party) wall construction within the central cavity between the two lines of blockwork to provide the level of sound reduction required according to Approved Document E (England & Wales) and Section 5 (Scotland).

Another important benefit of certain specifications and then correctly installing insulation in the cavity is that it can help contribute to a zero effective U-value in SAP* for this wall, reducing energy usage and making compliance with Building Regulation easier.

*as per Isover RD Party Wall Roll product datasheet on zero-effective U-value in SAP

Key Considerations

When using ISOVER products, you need to satisfy yourself that use of the product meets all relevant national Building Regulations and guidance as well as local, national and other applicable standards relevant for your construction or application, including requirements in relation to fire and applicable height restrictions. In addition to the product datasheet, please refer to the following product documents:

The building detail is for illustrative purposes only. It does not constitute advice and should not be relied upon.

Insulation products
Product Name Thickness Range Sizes Lambda
Isover RD Party Wall Roll 75-150mm Width 2 x 0.455m, Length 4 - 8.5m 0.036