The series of photographs above provide a good example of how much corroded steel wall ties can expand; and this can in some instances be up to twelve times the original thickness of material used. Note that only the section of tie inserted in the external face of this wall has corroded having been exposed to the severest weathering; but this is not always the case as wall location / orientation and, or quality of original wall tie material may dictate extent of corrosion.
The following series of photographs illustrate the typical damage pattern that corroded wall ties can create in a cavity wall, reducing its structural stability and in particular the ability to withstand horizontal wind loading. Cavity walls suffering from corroded ties generally exhibit horizontal bed joint cracking and occasionally diagonal cracks through perp joints radiating from corroded tie locations.
Thor Helical Remedial produce a wide range of wall ties to suit masonry of all types and strengths and locations. We can survey and specify a wall tie to accomodate any masonry composition and location. Most commonly used ties will be of the helical 'Drive Tie' type made of 304 grade stainless steel, or 316 grade for use in marine coastal environments.
The following series of photographs illustrate 'Drive Ties' being installed in combination with a number of 'Crack Stitch' bars to restore structural integrity to a wall. All existing wall ties will have been located and removed following installation of the remedial ties.
As an approved specifier and installer of the Thor Helical products we can offer an insurance backed 10 year warranty on Masonry Beam works for a small additional fee through Construction Guarantee Services Limited.