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P11 Foamed/ fibre/ bead cavity wall insulation

130 SURVEY OF EXISTING WALLS
• Timing: Before starting insulation work.
• Purpose: To confirm suitability for filling.
• Report: Submit, stating:
- Form of construction, materials used.
- General condition of walls.
- Thickness of walls.
- Width and condition of cavity.
- Exposure to wind driven rain.
- Nature and extent of remedial work and other work required to ensure suitability.
- Other information considered relevant.

140 REMEDIAL WORK TO EXISTING WALLS
• Responsibility: Contractor .
• Work to be carried out: As identified by the survey .
• Approval: Obtain before starting insulation work.

170 SUITABILITY OF WALLS
• Timing: Before and during filling of cavities.
• Defects: Report immediately.

230 CAVITY FILL
• Material: To be chosen by the Contractor.
- Type: Currently certified as suitable for the purpose and exposure situation by the
British Board of Agrément (BBA).
• U value before installation: site specific.
• Required U value after installation: site specific.
• Recycled content: Submit proposals.
• Installer: Approved in accordance with the BBA Surveillance Scheme.

310 GAPS AND OPENINGS
• Gaps: Seal with tightly packed mineral wool to prevent loss of fill.
• Openings: Fit approved sleeve to keep openings permanently clear.
• Air bricks/ grilles of untrunked vents: Remove and seal openings into cavity.

320 INJECTION HOLES
• Arrangement: Form neatly to a regular pattern and to sizes recommended by
cavity fill manufacturer.
• Before commencing filling of each wall: Form all holes in that wall.
• Precautions: Avoid damage to dpcs, cavity trays, flues, etc.
• Debris: Prevent from falling into cavity.

330 MAKING GOOD
• Blockages: Remove from vents and refix or replace any air bricks.
• Injection holes: Fill, replacing existing materials where possible.
- Finished appearance: Obtain approval of first few holes before completing the
remainder.

RotF generic (intermediate) NBS 2014 6118-AEW-XX-XX-NBS-A-01