INSTALLATION FluxCore wall system
Build the system.
Step by step.
Five installation films take you from tools and timber framing through FluxCore clip placement, insulation, gypsum fibreboard and the final damping layer.
The guide shows the construction sequence and the details that matter most for preserving mechanical decoupling.
Start with Step 1 ↓BEFORE YOU START
Accuracy is part
of the system.
FluxCore is designed as part of a complete construction. Keep the framing straight, avoid rigid bridges across the decoupled structure, maintain the specified clearances and seal the lining carefully. Project-specific engineering and local structural, fire and building requirements always take precedence over this general installation guide.
01 Installation sequence
Tools & Materials
Prepare the complete tool and material set before starting the wall. Correct measuring, cutting, levelling and fixing tools make the installation considerably faster and more accurate.
KEY INSTALLATION POINTS
- 2×4 timber studs for the structural wall
- ProSilence steel studs and FluxCore Clips
- Insulation and gypsum fibreboard
- FluxCore Compound and acoustic sealant
- Suitable screws, measuring, cutting and levelling tools
02 Installation sequence
Stud Wall Framing
Build a rigid and accurately aligned timber framework as the structural foundation for the decoupled FluxCore wall.
KEY INSTALLATION POINTS
- Measure accurately and cut the timber to length
- Use double bottom and top plates where additional rigidity is required
- Use double end studs for increased rigidity
- Install the remaining studs at 600 mm centres
- Use a cross-line laser and spirit level throughout the installation
- Finish with vertical bracing for maximum rigidity
03 Installation sequence
Installing the FluxCore Clips
Install the FluxCore Clips and steel studs that form the mechanically decoupled mounting structure for the inner wall.
KEY INSTALLATION POINTS
- With double bottom and top plates, position the first and last clip rows approximately 200 mm from floor and ceiling
- With single plates, approximately 100 mm can be used
- Space the remaining rows evenly at approximately 500–700 mm intervals
- Secure each steel bracket with an 80 mm wood screw through the centre
- Join steel studs with a 100–200 mm overlap and four self-drilling screws per joint
- Insert the FluxCore isolator, level each clip precisely and tighten securely
04 Installation sequence
Insulation & First Board Layer
Install the first gypsum fibreboard layer accurately, seal the construction and add the insulation before closing the opposite side.
KEY INSTALLATION POINTS
- Score gypsum fibreboard 2–3 times before snapping, or use a saw for fine trimming
- Use a 6 mm spacer below the board and approximately 3 mm at the side
- Maintain more than 2 mm clearance where the ceiling is uneven
- Use Fermacell gypsum fibreboard screws; pre-drilling is recommended
- Use approximately 4–5 screws per row and make sure they are securely seated
- Seal every board layer generously with noiseproofing sealant
- Install the insulation after the first side has been boarded
05 Installation sequence
FluxCore Compound & Second Board Layer
Complete the wall with the damping compound and a staggered second layer of gypsum fibreboard.
KEY INSTALLATION POINTS
- Use approximately 1 kg / 1 litre of FluxCore Compound per 600 × 2400 mm board
- Spread the compound evenly with a coarse notched trowel
- Stagger the second-layer joints so they do not align with the first layer
- Level the first board precisely before continuing
- Do not screw the second board layer into the metal channel — fasten it only to the first gypsum fibreboard layer
- Use approximately 4–5 screws per row and 4–5 rows over the full board height
3D DETAIL GUIDE Supplementary installation video
Door frame, threshold and floor.
A supplementary SketchUp walkthrough of the construction, including the sound-door frame, the floor on U-BOAT supports and the closure at the threshold.
FLOOR AND LOWER SEAL FIRST — DOOR SECOND
- Build the internal floor and close its exposed edge first. Plan the complete finished floor height, but leave the door opening clear. Support the floor on U-BOAT. The usual build-up above the joists is chipboard, Compound and one layer of gypsum fibreboard, plus any floor finish. A second gypsum fibreboard layer is optional. Fix the vertical floor-edge lining to the floor's own support.
- Seal the lower floor-edge junction while access is unobstructed. Apply suitable flexible sealant at the lower edge and other accessible perimeter junctions, without rigid contact. Inspect the seal before installing any raised door support, threshold or frame: these would otherwise block access to the lower junction.
- Only then install the raised support and the door. Set the door height to suit the finished internal floor level. Fix the frame directly to the outer structure and support the threshold independently of the decoupled floor, following the door manufacturer's instructions. Do not damage the completed lower seal. The door itself is not mechanically decoupled in this arrangement.
- Finish the accessible upper junction and any cover strip last. Maintain clearance between the floor and the fixed threshold and seal the upper junction with suitable flexible sealant. The lower seal was completed in Step 2; do not leave it until this stage. A cover strip must not screw, clamp or otherwise bridge the two structures together.
Alternative: a low threshold at the outer room's floor level — outward-opening doors only. Instead of raising the door, retain its threshold at the outer floor level. This leaves a step up to the higher internal floor. A finishing strip can conceal the closed floor edge; in this alternative it is fixed only to the decoupled floor construction and kept clear of the fixed frame, threshold and outer floor. Close and seal the floor edge before installing the door and strip. The strip is decorative, not a substitute for the sealed lining. No raised support is used, but the threshold still requires normal support in accordance with the door manufacturer's instructions.
An older visual overview, not a replacement for current instructions. The numbered sequence above describes the raised-threshold arrangement; the low-threshold alternative requires an outward-opening door. Build and seal the floor edge first in either case. Current product instructions and project drawings govern dimensions, materials, support and fixings.
INSTALLATION PRINCIPLES
Protect the
decoupling.
The clip, channel, board layers, sealing and damping interface work together. Small details can create unwanted rigid connections, so the final construction should follow the project drawings and product instructions rather than treating the clip as an isolated component.
Keep it aligned.
Level the framing, steel studs, clips and first board layer accurately.
Keep it separated.
Maintain perimeter clearances and avoid mechanical bridges across the decoupled structure.
Keep it sealed.
Seal the intended board perimeters and joints thoroughly with suitable acoustic sealant.
Stagger the layers.
Offset the second-layer joints and keep second-layer fixings out of the metal channel.