When the exterior masonry began to fail on a building extension at Ella Flagg Young Elementary School in Chicago, only 10 years after its completion, it was discovered that it had been constructed with insufficient and poorly installed wall ties. The brick veneer has now been secured and made completely safe following the installation of some 19,000 DryFix retrofit wall ties from masonry repair specialist, Helifix Ltd.
The 10mm diameter ties were specified by the structural engineers for the contract, following previous good experience of DryFix on other projects. Their rapid installation leads to low installed costs, they provide a secure and reliable connection and, because they are fully concealed and hidden in the mortar joints, they leave the building unmarked.
To ensure sufficient lateral restraint of the outer masonry, the local contractor undertook installation of the 19,000 ties on the three story school building addition. Small pilot holes were drilled through the veneer mortar joints and into the variable hollow and filled backup blocks. The DryFix ties were then simply power-driven into position, using a special attachment, to provide a secure and reliable connection without the need for grouts, resins or mechanical expansion.
With the brick veneer stabilized, structural integrity was restored to the Ella Flagg School building removing any potential of possible structural collapse.