Decoupled Ceiling Solution for an Exposed Timber Joist Ceiling

Decoupled Solution for New or Existing Ceiling where the Plasterboard / Ceiling Lining has been Removed: 43.5mm - 94mm

Application: - simple slim solution offering a high performance with absolute minimal loss of living space, where the existing ceiling has been removed.

Construction (Timber Joist Ceiling):
- ceiling where existing lining has been removed.
- 100mm x 45kg/m3 density mineral wool fitted within cavity OR
- 48mm x 48mm timber battens with 50mm x 45kg/m3 density mineral wool between battens.
- 16mm Resilient Bars.
- 15mm Phonewell® sound insulation.
- 12.5mm or 15mm sound resistant plasterboard.
- (optional second layer of plasterboard).

Please note, removing an existing ceiling from a separating floor between dwellings may require 2 x 15mm sound resistant plasterboards and 100mm (min) x 10-45kg/m3 (min) mineral wool between joists to meet the fire regulations, consult local building control.

Materials List (available from our stockists)
- 100mm x 45kg/m³ density mineral wool fitted between joists if accessible
- Optional 48mm x 48mm timber battens
- Optional 50mm x 45kg/m³ density mineral wool between battens, if used
- Resilient bars (3m x 75mm x 16mm)
- Drywall screws to secure resilient bars to joists or battens
- Phonewell® Acoustic Insulation (1200mm x 800mm x 15mm)
- Drywall screws (25mm length) to secure Phonewell® to resilient bars
- Sound resistant plasterboard (2400mm x 1200mm x 12.5 or 15mm)
- Drywall screws (38mm length) to secure plasterboard through to resilient bars
- Flexible mastic or Acoustic sealant.

Instructions: (have you considered Flanking Noise?)
1. Make existing ceiling sound by removing any loose material.
2. If access to joist cavity fit 100mm x 45kg/m³ density mineral wool.
3. If using 48mm counter-battens (due to not being able to gain access to the joist cavity), secure them at 400mm centres and perpendicular to the joists. Fill the void between the battens with 50mm x 45kg/m³ density mineral wool.
4. Secure the resilient bars at 400mm centres and perpendicular to joists (or battens if used) using drywall screws. Ensure bar ends do not touch the perimeter walls - leave a 5mm gap.  Note: the first and last bars should be approximately 50mm clear of the nearest walls. These bars can be reversed to ease installation.
5. Screw Phonewell® into the resilient bars with 25mm drywall screws which must not make contact with the timber structure, being careful to leave screwheads just below the surface.  Do not leave any gaps. See Cutting Phonewell.
6. Screw plasterboard through Phonewell® into the resilient bars with 38mm drywall screws, being careful to stagger joints and leaving a 5mm perimeter gap around the perimeter walls. Optionally add second layer of plasterboard with staggered joints.
7. Seal 5mm perimeter gaps with flexible mastic or acoustic sealant.
8. Finish plasterboard as required.
9. Consider treating any identified flanking walls with Phonewell®.