A non-loadbearing external wall construction including a 20mm deflection head with one layer of Glasroc X Sheathing Board 12.5mm to external side and three layers of Gyproc FireLine 15mm to the internal side of 100mm SFS framework. 50mm Isover Acoustic Partition Roll (APR 1200) in the cavity. For heights up to 4000mm.
Fire Integrity (mins)
Fire Insulation (mins)
Sound Insulation (Airborne) Rw (dB)
Maximum Height (mm)
|StandardsBS EN ISO 10140-2,Acoustics - Laboratory measurement of sound insulation of building elements. Measurement of airborne sound insulation.||Standard types|
|StandardsBS EN 1364-1,Fire resistance tests for non-loadbearing elements - Walls.||Standard types|
|Fixing strap||Gypframe GFS1 Fixing Strap|
|Screws side 2||Layer 1: Glasroc X Screws 25mm|
|Stud fixing||British Gypsum Wafer Head Jack-Point Screws 13mm|
|Board side 1||Layer 1: Gyproc FireLine 15mm
Layer 2: Gyproc FireLine 15mm
Layer 3: Gyproc FireLine 15mm
|External board joints||Glasroc X Sealant|
|Insulation||Layer 1: 50mm Isover Acoustic Partition Roll (APR 1200)|
|Abutments and openings||100mm Hadley SFS Stud|
|Stud||100mm Hadley SFS Stud|
|Base channel||104mm Hadley SFS Channel|
|Head channel||104mm Hadley SFS Channel|
|Screws side 1||Layer 1: British Gypsum Jack-Point Screws 25mm
Layer 2: British Gypsum Jack-Point Screws 41mm
Layer 3: British Gypsum Jack-Point Screws 60mm
|Board side 2||Layer 1: Glasroc X Sheathing Board 12.5mm|
This section should be read in conjunction with the Products list.
- Abutment Fixing: SFS stud (100mm x 50mm x 1.2mm) suitably fixed to structure at 600mm centres.
- Base Channel Fixing: SFS channel (104mm x 40mm x 1.2mm) suitably fixed to floor at 600mm centres. All SFS components are supplied direct from Hadley Group.
- Deflection Allowance: For vertical movement up to 20mm. To be determined by a Structural Engineer.
- Dropped Soffit: For principles of deflection head construction refer to detail ST‐225-ZZL3-02
- Finishing Requirements: To achieve the specified performances, the system should be finished using either one of our Thistle or ThistlePro plasters, or Gyproc jointing products to the internal face. See the product range guides on the British Gypsum website for more information.
- Fixing Strap: Used to support horizontal board joints to internal side and enable board screw fixing at 300mm centres.
- Loadbearing: No
- Maximum Height: The maximum heights quoted are limited by the fire state field of application or by limiting deflection of L/240 at 200 Pa, whichever is the lower of the two.
- Other Requirements: SpecSure® system performance warranty confirms that British Gypsum proprietary systems will perform as specified for the lifetime of the building. The SpecSure® warranty requires that all components are specified in full and constructed in accordance with British Gypsum’s installation guidance. For more details see the British Gypsum website. Always check with the design team before making any changes to the chosen specification, ensuring appropriate substantiation is sought to confirm that the solution still meets all required project performances.
- Screw: Board side 1, Layer 1 (inner) and Layer 2 (middle), fix securely to SFS supports around the perimeter of the board at maximum 300mm centres except the head channel; Board side 1, Layer 3 (outer), fix securely to all SFS supports around the perimeter of the board and intermediate stud positions at maximum 300mm centres except the head channel. The uppermost board fixings are positioned 130mm below the structural soffit through board in to fixing strap. Board side 2, Layer 1, fix securely to all SFS supports around the perimeter of the board and intermediate stud positions at maximum 300mm centres except the head channel. The uppermost board fixings are positioned 130mm below the structural soffit. External corners reduce fixings to 200mm. All joints staggered between layers. First fixing of the external board into the stud should be 100mm above the floor channel leg and then fixed working up the stud (board side 2). Fix working from the centre of each board on the internal side (board side 1). Position screws not less than 13mm from cut edges and 10mm from bound edges of boards. Set screw heads flush with plasterboard surface; do not break gypsum core.
- Sealant: On the internal side, locate sealant at junctions with adjoining structure and other air paths. Apply as a continuous bead to clean, dry, dust-free surfaces, leaving no gaps. After application of sealant, bulk fill gaps between floor and underside of plasterboard using Gyproc joint compound.
- Stud Centres (mm): 600 mm
- Approx. Weight (kg/m2): 51 kg/m²
- Head Channel Fixing: SFS slotted channel (104mm x 70mm x 2.0mm) suitably fixed to soffit at 600mm centres.
- External board joints: Apply a continuous 6mm bead of Glasroc X Sealant along vertical and horizontal edges of board where boards will abut each other. Push the sheathing board up to the previous board ensuring the sealant 'mushroomed' out fully sealing the joint.
- Stud Fixing: SFS studs (100mm x 50mm x 1.2mm) should be cut 25mm short and engaged into the slotted head channel and fixed through the slots with British Gypsum Wafer Head Jack-Point Screws 13mm each side of stud (25mm below the top of the slot)
Need CAD, BIM, Test Reports and Technical Specifications?
Log in to access CAD .dwg files.
Log in and add a System Specification to a Project to access BIM files, Test Reports, and Technical Specification files.
Please add this Specification to a project and go to that Project to access the related Test Reports.
|Test report label||Test report name|
|Test report labelSound Insulation Test Report||Test report nameBTC 21850A|
|Test report labelFire Resistance Test Report||Test report nameBTC 21749F|
|Test report nameBTC 21755F|
A unique warranty that confirms British Gypsum proprietary systems will perform as specified for the lifetime of the building.