CAN undertook the installation of Helifix Dry Fix (retro fit wall ties) and metal straps to the gable ends of three tower blocks.
Failure of inadequate wall ties to a gable end cavity wall resulted in a complete brick panel falling to ground level from a high rise building. As a result, the property owner required repairs to ensure the safety of three similar tower blocks.
Works comprised installation of remedial wall ties to the gable ends on all three buildings, to ensure that the outer brickwork panels were securely fixed to the inner blockwork leaf and concrete frame, thus preventing a future reoccurrence of the failure.
CAN’s fabric maintenance team selected rope access to assist in undertaking this task, working on a top-down basis to ensure that personnel were never required to work directly beneath potentially loose and unstable brickwork.
CAN installed Helifix Dry Fix wall ties over the top 16 floors to the gable ends on all 3 tower blocks.
A variation in cavity from 20mm to 100mm required the measurement of the cavity depth at each tie location prior to tie installation. It was necessary to ensure a minimum 50mm penetration into the inner leaf, to ensure a secure fixing, and a maximum of 70mm to avoid any damage to internal finishes and services.
To provide additional restraint to the outer skin of brickwork, 2m long retention straps fabricated from mild steel with an epoxy coating were installed to the face of the outer skin of brick work and anchored using threaded rod chemically fixed to the concrete columns.
Duration: 3 Months
Client: London Borough of Hammersmith and Fulham