12.5mm Gyproc Fireline Duplex - 1200mm x 2400mm - British Gypsum

12.5mm Gyproc Fireline Duplex is British Gypsum’s fire‑resistant plasterboard with an integrated vapour control layer, designed for internal walls and ceilings where enhanced fire protection and condensation control must be achieved in a single board. It combines the proven performance of Gyproc Fireline with a factory‑bonded foil backing, making it ideal for external wall linings and warm‑to‑cold interfaces. 

Gyproc Fireline Duplex is a specialist gypsum board featuring a glass‑fibre‑reinforced fire‑resistant core and a metallised polyester foil on the reverse face. This dual‑function design provides improved fire resistance while acting as a vapour control layer (VCL) to limit moisture movement into the building fabric. The board is used in partitions, wall linings and ceiling systems where both fire performance and vapour control are required—particularly in external walls, rooms‑in‑roof, and loft conversions. Its smooth face is suitable for direct decoration, skim finishing or tiling.

Because it delivers fire protection and vapour control in one board, simplifying installation while ensuring compliance with fire‑safety and moisture‑management requirements—ideal for modern external wall and ceiling systems.

• Face colour: Pink
• Reverse colour: Metallised polyester film

Edge options: Tapered edge, 2 tapered edges

• Fire‑resistant gypsum core reinforced with glass fibre
• Integrated vapour control layer - no need for separate membranes
• Two‑in‑one performance for faster installation and reduced material use
• Suitable for external wall linings and warm‑to‑cold junctions
• Smooth, finish‑ready surface for plaster, paint or tiles
• BES 6001 ‘Excellent’ responsible sourcing rating
• Compliant with EN 14190 for laminated gypsum boards

• Internal wall dry‑lining systems
• Ceilings and partitions requiring both fire protection and vapour control
• Rooms‑in‑roof and loft conversions
• Areas with condensation risk (e.g., cold‑side interfaces)
• Upgrades to existing walls where a VCL is required

• Ensure metal or timber studs are plumb, level and securely fixed
• Standard stud spacing: 600 mm centres (or 400 mm for higher performance)
• Confirm all services are installed and tested before boarding
• Foil side always faces the cavity/external wall, not the room
• Decorative face (pink paper) faces into the room
• Keep the foil intact - do not puncture unnecessarily
• Use drywall screws: 25 mm for single layer, 38 mm for double layer
• Fix at 300 mm centres on studs
• Keep screws 10 mm from tapered edges and 13 mm from cut edges
• Ensure screw heads are slightly recessed but not breaking the paper
• Seal all board joints with foil tape or approved VCL tape
• Seal around electrical boxes, pipes and service penetrations
• Avoid gaps between boards - tight joints maintain VCL integrity
• Apply joint tape (paper or fibre) to all joints
• Use Gyproc jointing compound in two or three coats
• Sand lightly once dry for a smooth finis
• Confirm all foil-backed areas are sealed with no tears or gaps
• Check screw heads are filled and joints are smooth
• The board is now ready for skim coat, paint, or tiles