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330 INSTALLATION OF WALL TIES GENERALLY
      • Masonry:
          - Stable at all times during wall tie installation.
          - Formation of holes: Minimize.
          - Cavities: Clear and free from debris.
          - Fixing holes: Clean.
      • Wall ties:
          - Installation: Accurately and securely.
          - Drips: Centred on cavity.
          - Expansion anchor fixings: Set to the correct torque.
          - Bonded fixings: Thoroughly grouted.
      • Facework: Keep clean.

340 POSITIONING OF WALL TIES
      • Spacing of wall ties: site specific .
      • Additional ties:
          - Reveals of unbonded openings and edges (including gables and movement
             joints): Fix additional ties within 225 mm at 300 mm maximum vertical centres .
          - Cavities with insulation batts: Beneath the lowest row of insulation batts .

350 REMOVING MASONRY UNITS FOR REUSE
      • Removal of units: In one piece. Clean and set aside for reuse.
      • Units unsuitable for reuse: Obtain instructions.
      • Adjacent masonry:
          - Joints: Do not damage or widen.
          - Old mortar: Remove.
          - Cavities: Keep clean.

355 REMOVING MASONRY UNITS
      • Adjacent masonry:
          - Joints: Do not damage or widen.
          - Old mortar: Remove.
          - Cavities: Keep clean.

360 CORE DRILLING MASONRY WITH RENDERED FINISH
      • Drilling: Carefully and accurately to provide access to existing ties.

365 REMOVAL OF EXISTING WALL TIES FROM INTERNAL LEAF
      • Wall ties: Remove carefully and completely.
      • Internal leaf/ finishes: Minimize disturbance.

368 REMOVAL OF EXISTING WALL TIES FROM EXTERNAL LEAF
      • Wall ties:
          - Flexible wire ties: Crop or bend down against face of internal leaf.
          - Rigid ties: Crop against face of internal leaf.
      • Internal leaf/ finishes: Do not disturb.

 370 MAKING GOOD OF CAVITY WALL INSULATION                                      6118-AEW-XX-XX-NBS-A-01
       • Cavities: Clear of dirt and debris.
       • New insulation: Agrément certified .
            - Thickness: To match existing.
            - Installation: Secure. No gaps.

RotF generic (intermediate) NBS 2014
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