Wall Tie Inspection

Wall Tie Inspection

Wall ties, usually galvanised, pitch coated, stainless steel or plastic based are used to tie together two skins of brick/block/concrete together.  Ties in older buildings are often subject to failure and inspection is often undertaken either as routine measure or where visible defects such bulging, movement of the wall and/or cracking of the wall is evident.

Position of wall ties can be identified by use of a metal detector and the position of ties plotted.  Visual examination of the condition is undertaken by borescope with access to the wall cavity from localised inspection points drilled at the location of the tie.  It is important to identify the wall tie position accurately as often insulation materials and debris prevent clear views of the tie condition.

Assessment is undertaken  in accordance with the criteria outlined in BRE Digest 401 “Installing Wall Ties “, which set out how to visually grade existing wall ties and what recommendations are made depending upon condition. BRE 401 identifies nine categories of wall tie corrosion, ranging from number 1: Bright and shiny – no problem, though to number 9: very rusty and laminating – urgent repair required.

In addition to wall tie inspection, Nicholls Colton Group also inspect cavity walls for:

  • The width of the cavity
  • Detailed visual inspection within the cavity investigating area to be filled including wall tie position and condition
  • The condition of the structure for damp or condensation issues
  • The services through the cavity which would be affected by cavity fill, e.g. ventilation, gas flu
  • Presence of insulation/voids/debris