Celotex GA4000 insulation boards, focusing on measurements, cutting, fixing, and sealing:

Measuring and Cutting

1. Flat Roofs (Below Timber Joists):
   • Measure the space between joists precisely.
   • Cut the board to fit snugly, leaving a 10mm gap around the perimeter for expansion.
2. Flat Roofs (Between Timber Joists):
   • Measure joist spacing and subtract 2-3mm for a friction fit.
   • Use a straight edge and a fine-toothed saw or a sharp utility knife for cutting.
3. Pitched Roofs (Between Timber Rafters):
   • Measure the gap between rafters. Cut the insulation board 1-2mm smaller for a tight fit.
   • For angled cuts, use an angle finder and mark the board before cutting.

Fixing

1. Flat Roofs (Below Timber Joists):
   • Use appropriate screws and washers, spaced at 300-400mm intervals.
   • Ensure the fixings are long enough to penetrate both the insulation board and into the joist by at least 25mm.
2. Pitched Roofs (Below Timber Rafters):
   • If mechanically fixing, use fixings that are suitable for the depth of the insulation and the rafter.
   • Space the fixings at 600mm centers along the rafters.
3. Wall Applications (Solid Masonry Internal Linings):
   • Use a combination of adhesive and mechanical fixings.
   • Adhesive should be applied in continuous beads approximately 300mm apart.

Sealing

1. All Roof and Wall Applications:
   • Use airtight tape specifically designed for insulation boards to seal all joints.
   • Ensure all cuts are clean and straight for effective sealing.
2. Vapor Barriers:
   • Overlap vapor barrier sheets by at least 100mm.
   • Seal overlaps with vapor barrier tape.
3. Around Penetrations:
   • Use expanding foam or sealant for gaps around pipes, cables, or other penetrations.
   • Ensure the foam or sealant is compatible with the insulation material.

Additional Tips

• Accuracy: Always double-check measurements before cutting. A slight error in measurement can lead to gaps and reduced insulation efficiency.
• Cutting Surface: Use a stable and flat surface for cutting. A workbench with a cutting mat is ideal.
• Tools: Keep your cutting tools sharp. Blunt tools can lead to uneven edges, making it harder to seal joints effectively.
• Handling: Handle the boards with care. Despite their rigidity, the edges can be prone to damage if mishandled.
• Clean Work Area: Keep your work area clean. Debris and dust can hinder proper adhesion of tapes and sealants.