Insulation Between Properties or Rooms
Due to the introduction of standards for the reduction of noise upgrades to flooring on conversions completed before 1992 can have significant effects on sound insulation. Conversions from mid 2003 onwards should comply with existing Building Regulations for sound transmission, as should that for new buildings.
The Building Regulations 2010 Approved Document E (updated since 2003) relates to “Resistance to the passage of sound”. It introduced pre-completion sound testing for sound insulation as a means of demonstrating compliance. However from 2004 use of robust details in new houses and flats has been accepted as an alternative to testing. These include wall and floor constructions that provide good sound insulation performance.
The regulations require that:
• Dwelling houses, flats and rooms for residential purposes be designed and constructed in such a way that they provide reasonable resistance to sound from other parts of the same building or adjoining buildings;
• Internal walls between a bedroom or room containing a water closet, and other rooms, and internal floors should provide reasonable resistance to sound; and
• Common parts should be designed to prevent more reverberation than is reasonable.
It sets out the standards for sound insulation testing and includes construction standards for walls and floors of new buildings and flats formed by a material change of use (converted property).
However, whilst buildings may be constructed appropriately and pass any testing they may not provide your desired level of insulation. Hence, you may still wish to consider insulation as an option.
What You Need to Do
You can employ a specialist (or builder who understands what needs to be achieved) or, if you have some basic DIY skills, complete the works yourself. Most of the materials you use can be obtained from builders merchants. However, there are also a number of specialist systems and materials available from sound insulation supply companies that you may also wish to consider using.
As well as noise that travels directly through the air from one room to the next, noise can also take an indirect route along solid materials such as walls. It is important to understand this principle as it may affect what work you will need to complete. Try to establish what route the noise is taking to come into your property.
In the case indirect (structure-borne) noise it may be necessary to build an independent wall or ceiling over the existing structure. By “independent” we mean that there should be no (or limited) connection to the existing structure so that transmission through the material is reduced. Where noise enters the room directly from above or below a similar solution may be applied to the floor above, ceiling below, or both.
Build a studwork frame by attaching the top and bottom timber plates to the floor and ceiling of the room; creating a narrow airspace between the studwork and the wall (do not attach studding to the existing wall). Hang the insulating material inside the cavity (or attach to the rear of the studwork depending upon type/thickness) making sure that the layer is continuous without gaps. Line the studwork with two layers of plasterboard (overlapping edges and sealing all joints).
As an alternative to the above, plaster boarding may be attached to resilient channels (with neoprene padding) attached to wall battens. This may reduce the loss of space to under 2 inches. Acoustic linings will need to be applied.
As above the idea is to provide an independent ceiling by running new ceiling joists from new wall plates placed under the existing ceiling. Line with mineral wool and attach two layers of plasterboard as above.
With ceilings, in particular the above method may result in loss of a substantial volume of the room if the ceiling are already low. Instead consider using resilient channels by attaching to the joists (or studwork) of the existing joists before adding insulation and plasterboard layers. Specialist resilient kits can be obtained which provide more effective solutions. Where solid (as opposed to timber) constructions are in place resilient fixtures are available for attaching resilient channels.
Again, the basic principle is to provide a separate layer above the existing surface. You will need to remove the skirting in place. Remove the original floor surface and fit a suitable insulating material between joists. Replace the floor. Lay a continuous layer of floor insulation material and cover with a thin layer of plasterboard (loosely). Finish with a layer of tongue and groove chipboard without nailing. Replace skirtings. Adjust doors and stairs as necessary.
The above method will increase the floor height considerably. We would advise considering a resilient floor surface and specialist insulating material or application as an alternative.