A non-loadbearing external wall construction, including a 20mm deflection head, with an inner layer of Glasroc X Sheathing Board 12.5mm and outer layer of 50mm Isover Polterm Max Plus insulation to external side and one layer 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|
|External insulation||Layer 1: 50mm Isover Polterm Max Plus|
|Insulation||Layer 1: 50mm Isover Acoustic Partition Roll (APR 1200)|
|Base channel||104mm Hadley SFS Channel|
|Head channel||104mm Hadley SFS Channel|
|Abutments and openings||100mm Hadley SFS Stud|
|Stud||100mm Hadley SFS Stud|
|Board side 1||Layer 1: Gyproc FireLine 15mm|
|External board joints||Glasroc X Sealant|
|Screws side 1||Layer 1: British Gypsum Jack-Point Screws 25mm|
|Screws side 2||Layer 1: Glasroc X Screws 25mm|
|Fixing strap||Gypframe GFS1 Fixing Strap|
|Stud fixing||British Gypsum Wafer Head Jack-Point Screws 13mm|
|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-ZZL1-02
- 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 layers are fixed securely to SFS framing 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. Fix working from the centre of each board on the internal side. 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): 32 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.
- External Insulation fixing: External insulation must be correctly installed to ensure the performance of our system. Attach Isover Polterm Max Plus insulation 1200 x 600mm in a horizontal orientation and brick stagger with one fixing through the centre of each slab into the SFS framework. Add two further fixings 400mm apart up the slab’s vertical edge into the SFS framework. Steel fixings are stainless steel self-drilling insulation fastener screw 6.3mm diameter by others with length sufficient to ensure minimum 10mm threaded penetration of the fixing into the SFS framework. Insulation is retained with stress plate square retaining washers, 70mm x 70mm, 6.8mm diameter central hole by others.
- 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)
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|Test report label||Test report name|
|Test report labelSound Insulation Test Report||Test report nameBTC 21830A|
|Test report labelFire Resistance Test Report||Test report nameContact Technical Support Team|
A unique warranty that confirms British Gypsum proprietary systems will perform as specified for the lifetime of the building.