Wall Tie Failure
Target's Method of Repair
Target's Retro Flex wall tie replacement system is helical tie that can be installed from the outside or inside of a structure.
Retro Flex is inserted through an oversized hole in the near leaf and is installed into the inner leaf using a hammer action (similar to a nail). The Retro Flex is fixed to the near leaf using Polyester Resin or Bond Flex. Retro Flex is a non-expansive remedial wall tie and does not suffer from the same problems that an expansive fixing has.
Every Retro Flex installation can be proof tested of its connection to the far leaf using a Target Load Test Unit, but is more commonly performed randomly as installation proceeds.
Because the fixing method employed does not induce additional stresses into the substrate Retro Flex can be used in many and varied materials, from poured concrete columns to aircrete blocks, with satisfactory results and there is no concern to achieve the vital edge distance spacing necessary with any expansion fixing.
The design of the Retro Flex remedial tie ensures that any potential for installer error can be minimised. The multiple drip design of each fin allows the Retro Flex to be installed at an angle of up to 25° towards the inner leaf without the possibility of any water transfer across the cavity. It is recommended that each Retro Flex is installed horizontally.
The Retro Flex installation procedure is outlined below:
- Drill a 10mm or 12mm hole through the near leaf using a SDS hammer drill. The hole should be 25mm from the end of any brick and on it's horizontal centre.
- Push the pilot drill and drill extension through the previously drilled hole and drill a pilot hole into the far leaf. Note: If the far leaf is a soft material this procedure may be omitted.
- Insert the Retro Flex tie into the Power Support tool, insert the combination through the hole in the near leaf and, using a SDS hammer drill, drive the Retro Flex tie into the pilot hole in the far leaf.
- Once the Retro Flex tie is installer into the far leaf pilot hole the holding capability can be checked using a Target Load Test Unit. As a general rule about 1kN loading in tension is an adequate bond.
- After an acceptable proof test is performed the near leaf connection is made using Target Polyester Resin or Bond Flex XL cementitious grout. The drilled hole may then be colour matched for an excellent finish.