Sound and fire protection in walls, floors and ceilings

Voices, music and television are airborne noise, carried through walls and floors. Footsteps, dropped objects and doors closing are impact noise, mostly a problem through floors. Flanking is sound that goes around an upgraded wall, through a shared floor void, a chimney breast, a party wall in the loft or a gap behind skirting. Treating only one wall often disappoints because of flanking.

Against a party wall, the usual upgrade is an independent lining: a new stud or metal frame standing just off the existing wall, not touching it, filled with mineral wool and lined with one or more layers of dense board. Resilient bars or clips isolate a new ceiling from the joists above. Floors can be improved with acoustic insulation between joists, a resilient layer and a floating floor. Each of these takes some room space, which should be agreed before work starts.

Approved Document E applies to new homes and to homes formed by a material change of use, such as a house converted into flats. Separating walls and floors between the new dwellings must resist sound to the required standard, and the building control body may require a pre-completion sound test. Internal walls around bedrooms and rooms with a WC in those new homes need a minimum laboratory sound insulation rating set in Approved Document E, with exceptions for walls containing a door and between an en suite and its bedroom.

In a loft conversion, sound insulation between the new rooms and those below is checked, and on terraced or semi-detached houses the building control body may ask for the party wall in the loft to be upgraded. Improving sound in your own existing house for comfort, outside those projects, is usually not controlled, which is why the specification in the quote matters.

Source: gov.uk

Fire protection in dry lining comes from tested systems: a particular board, number of layers, stud and fixing pattern that together achieve a stated period of fire resistance. Changing one part, such as using a different board or leaving out a layer, means the wall no longer matches what was tested. Every hole for a pipe, cable or socket box through a fire-resisting wall or ceiling needs appropriate fire stopping.

Typical domestic jobs include protecting the stairway in a loft conversion, lining the ceiling of an integral garage, and separating a new flat from the rest of a building. In a house with a storey more than 4.5 metres above ground, Approved Document B expects a protected stairway enclosed by fire-resisting construction. In commercial premises, fire-resisting partitions and ceilings are part of the fire strategy that the responsible person maintains.

• which noise or fire problem is being addressed, and where
• the system proposed, with the manufacturer's reference and tested rating
• how flanking routes, sockets and service holes are dealt with
• loss of room size from new linings
• whether Building Control approval or a sound test is needed
• what happens to skirting, sockets, radiators and decoration

Fixing extra plasterboard directly onto a party wall adds weight but gives little improvement, because the new layer vibrates with the old one. Leaving gaps at the edges, especially at the floor and ceiling, lets sound bypass the wall. Recessed downlights and back-to-back sockets make holes in ceilings and walls that carry sound and fire. Filling a cavity with expanding foam is not fire stopping unless the product is tested for that use.

Egg boxes and foam panels reduce echo inside a room; they do almost nothing to stop sound passing through a wall. If the problem is the neighbour, the answer is mass, separation and airtightness.

Describe the problem, the rooms and walls affected, and whether it is part of a conversion or other building project, then confirm your phone number and email. Businesses in your area see the job without your contact details, and exactly one can buy it; it is then removed from the list. We email you the business's name, address and phone number before your details are shared. You pay nothing, a taker is not guaranteed, and it is withdrawn after 21 days if unsold. Offrano checks only that buyers are registered businesses, so ask for the tested system in writing.