Celotex Isover

Insulation for Timber Separating Wall

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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 floor. 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 TFPWR PDS on zero-effective U-value in SAP

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


Insulation products to consider
Product Name Thickness Range Sizes Lambda BBA
ISOVER Timber Frame Party Wall Roll 50mm - 100mm Width 1200mm Un-split, Length 6000mm - 12000mm 0.036 W/m.K Tick Icon
ISOVER Timber Frame Roll 32 90-140mm Width 2x570mm, Length 2700-4200mm 0.032 W/m.K Tick Icon
ISOVER Timber Frame Roll 40 90-140mm Width 2x570mm, Length 6500-10130mm 0.040 W/m.K Tick Icon
ISOVER Timber Frame Batt 40 90-140mm Width 570mm, Length 1175mm 0.040 W/m.K Tick Icon
ISOVER Timber Frame Batt 35 90-150mm Width 570mm, Length 1175mm 0.035 W/m.K Tick Icon
ISOVER Timber Frame Batt 43 90-140mm Width 570mm, Length 1175mm 0.043 W/m.K Tick Icon
ISOVER Timber Frame Batt 32 50-140mm Width 570mm, Length 1175mm 0.032 W/m.K Tick Icon
ISOVER Timber Frame Roll 35 90-140mm Widths 2x570mm, 3x400mm (140mm only), Length 4000-5300mm 0.035 W/m.K Tick Icon