Cavity Wall Tie Replacement
Cavity wall design incorporating metal wall ties, has been in use since the beginning of the nineteenth century, to prevent rain penetration and to improve thermal insulation.
Over recent years, it has become apparent that a high number of properties, built before 1981 are suffering from premature wall tie corrosion.
Latest research by the Building Research Establishment, has found that wall ties corrode faster in the mortar within the external leaf of brickwork, leading to oxidisation where they will expand to several times their original size. This expansion will cause structural instability, by lifting the mortar Joints where they lay.
Visual evidence of corrosion can be seen by horizontal and diagonal stepped cracking to external wall surfaces. If corrosion is severe it will lead to distortion and bulging. In some cases external walls have collapsed during gales. Research has also found that a high percentage of properties inspected, had an inadequate number of wall ties especially around openings, i.e. windows and doors.
We have a range of solutions from Helical for various applications and wall types.