Ash deafening, or 'pugging' (occasionally mistakenly referred to as ‘deadening’) was traditionally used in the construction of buildings in Scotland to provide sound insulation in timber separating floors (floors designed to restrict the passage of sound between the spaces above and below the floor). It is commonly found in Georgian, Victorian, traditional tenement and four-in-a-block dwellings built before 1919. After 1930 separating floor constructions tended to become lighter, using ‘quilt’ insulating materials such as mineral wool instead.
Deafening generally comprises 70mm of ash and small stones from builder’s rubble. This usually rests on timber boards referred to as ‘deafening boards’ above a suspended ceiling. Two common configurations are illustrated below.
Problems or poor performance of deafening can be caused by lack of cover between joists and walls, or where deafening has been removed or moved during alterations to buildings. Water leaks can also wash deafening into the ceiling or wall constructions, and can damage plaster.
Ash deafening can now be difficult to source, and alternatives such as graded stone chips, dry sand or other crushed dense materials may be used instead. If sand or other fine particles are used, a lining sheet may be required to prevent particles falling between the deafening boards. Ash deafening typically has a mass of around 70 to 80 kg/m2, and so a structural engineer should be consulted before insertion.
 Find out more
 Related articles on Designing Buildings Wiki
- Building acoustics.
- Flanking sound.
- Floor insulation.
- Flooring defects.
- Impact sound.
- Separating floor.
- Sound absorption.
- Sound insulation in buildings
- Sound v noise.
- Structure-borne sound.
- Suspended ceiling.
 External references
- Housing and sound insulation, Improving existing attached dwellings and designing for conversions. Crown Copyright 2006. http://www.gov.scot/resource/doc/217736/0099123.pdf
LPOC notes ‘...it is perverse that repairs should be subject to VAT when new development is not'.
Loyd Grossman recently appeared on a BBC radio programme to discuss NIMBYism in heritage and development, the programme is currently available on BBC iPlayer.