The Ideal Solution for Soundproofing a Timber Joist Floor.

Floating Floor Solution (15mm Above) with Decoupled Ceiling Below (28.5 - 46mm Below)

Application: Building Regulations New Build, Change of Use, Remedial and Refurbishment.
Simple slim solution offering ultimate performance and minimal loss of living space, where the plasterboard / ceiling lining has been removed.

Construction: (Timber Joist Floor):
- sacrificial layer or FINISHED surface
- 15mm Phonewell® Sound Insulation
- 18mm chipboard / OSB / floorboards
- 235mm solid timber joists
- 100mm x 10-45kg/m³ mineral wool
- 16mm standard Resilient Bars
- 15mm Sound Resistant Plasterboard
- second layer of 15mm Sound Resistant Plasterboard is required for New Build or Change of Use Separating Floors between dwellings for fire regulations, as shown.

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 between joists
- Phonewell® Acoustic Insulation on Floor (1200mm x 800mm x 15mm)
- Phonewell® Eco-Tape
- optional 3mm hardboard, and tacks, to make floor level and sealed
- 18mm chipboard / OSB / existing floorboards
- Resilient bars on Ceiling (3m x 75mm x 16mm)
- Drywall screws to secure resilient bars to joists
- Sound resistant plasterboard (2400mm x 1200mm x 12.5 or 15mm)
- Drywall screws (25mm length for 1st layer, 38mm length for 2nd layer) to secure plasterboard through to resilient bars
- Flexible mastic or Acoustic sealant

Instructions: (have you considered Flanking Noise?)
Joist Cavity
1. Fill the void between the joists with 100mm min. x 45kg/m³ density mineral wool, by accessing the void from above or below.

Floor
2. Examine the timber sub-deck and fill any holes or gaps with flexible mastic or acoustic sealant, tradesmen will often tack down 3mm hardboard sheets to level and seal.  Also seal around the perimeter walls.
3. Ensure the floor surface is clean and even.
4. Begin in one corner and lay the Phonewell® boards on the sub-deck, butted tightly up to the perimeter walls. Do not screw, nail or glue the boards down.
5. Butt each Phonewell® board up tightly to each other, leaving no gaps.  Lay the boards in a brickwork formation. See Cutting Phonewell®.
6. Install the finished floor surface as per Fitting Floor Finishes over Phonewell®.
7. Fit skirting boards ensuring no contact with the floor – leave a 2mm gap.

Ceiling
8. On the ceiling below, secure the resilient bars at 400mm centres and perpendicular to joists 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.
9. Screw plasterboard into the resilient bars with 25mm drywall screws, which must not make contact with the timber structure, leaving a 5mm perimeter gap around the perimeter walls. Optionally add the second layer of plasterboard with staggered joints, using 38mm drywall screws(see note above).
10. Seal 5mm perimeter gaps with flexible mastic or acoustic sealant.
11. Finish the plasterboard as required.
12. Consider treating any identified flanking walls with Phonewell®.