The corrosion of cavity wall ties results in the expansion of the metal embedded in the outer leaf of the masonry, eventually to a size several times its original thickness. Symptoms of cavity wall tie corrosion are usually visible through the 'jacking' action associated with this phenomenon. This can been seen as cracks within the mortar bed joints, slight separation of cross walls or stair stringers from flank walls, cracking of ceiling finishes as ceiling joists are pushed up, cambering of window sills and diagonal cracks over windows, especially soldier arch lintels.
The advanced corrosion of wall ties can incorporate significant outward bulging of the walls in addition to the above symptoms. Recently pointed mortar bed joints at regular intervals would also indicate that corrosion of the cavity wall ties might have occurred.
Our surveyor will carry out a visual inspection for wall tie corrosion using an optical borescope at several points within the cavity and a metal detector will also used to check the existing wall tie density. If it is determined that a secondary cavity wall tie installation is required, the correct system for the wall will be recommended. The cavity wall tie works carry a 30-YEAR GUARANTEE.
Alan Allison specialize in the repair and replacement of lintels.
Stepped mortar bed cracks and dropped brickwork above external window/door openings is normally due to defective, inadequate or no lintel support. In some cases on older properties the brickwork above the openings was built directly off the top of the timber windows. It is common to see problems (especially after later window replacement) if new lintels have not been installed or the brickwork was not adequately supported at time of works. If the brickwork has only dropped slightly it is possible to carry out a structural epoxy resin stitch repair (in-situ lintel), however in most cases it is necessary to install a new lintel to the correct specification.
We would be pleased to carry out an inspection and report our findings, including prices for any required works which would be emailed the same day.
*Please note: Our inspection and report does not constitute in whole or in any part a structural survey. Subject to our findings, it may be necessary to instruct a Structural Engineer to carry out a detailed inspection.