Insulation for Timber Separating Wall

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 timber separating (Party) walls is typically a glass mineral wool roll.

Isover Timber Frame Party Wall Roll can be installed as part of the separating (Party) wall construction within the central residual cavity between the two adjacent lines of studwork 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 residual cavity of a separating (party) wall 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 Timber Frame 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:

• BBA certificates - where applicable to the application
• Declarations of Performance
• Health & safety datasheets

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

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Insulation products

Product Name	Thickness Range	Sizes	Lambda
Isover Timber Frame Party Wall Roll	50mm - 100mm	Width 1.2m, Length 6 - 12m	0.036
Isover Timber Frame Roll 32	90-140mm	Width 2 x 0.57m, Length 2.7 - 4.2m	0.032
Isover Timber Frame Roll 40	90-140mm	Width 2 x 0.57m, Length 6.5 - 10.13m	0.040
Isover Timber Frame Batt 40	90-140mm	Width 570mm, Length 1175mm	0.040
Isover Timber Frame Batt 35	90-150mm	Width 570mm, Length 1175mm	0.035
Isover Timber Frame Batt 32	50-140mm	Width 570mm, Length 1175mm	0.032
Isover Timber Frame Roll 35	90-140mm	Width 2 x 0.57m or 3 x 0.4m (140mm only), Length 4 - 5.3m	0.035