THE PROBLEM The idea of cavity wall ties and indeed the installation of cavity wall ties are not recent issues. In the main, cavity walls have been constructed since the beginning of the 20th century, but specific types of cavity wall construction date back to far earlier periods in history. Cavity walls were constructed to offer protection from the elements, and to create better thermal qualities. They consist of two separate walls "tied" together using some form of "cavity wall tie". Large numbers of walls with metal wall ties were constructed in the building boom of the 1930's. After the Second World War, cavity walls became a standard form of construction for dwellings, and many other forms of buildings. Old metal wall ties commonly came in the form of a strip of metal, with a sacrificial protective coating of either black bitumen or zinc. In the early 1980's the problem of cavity wall tie corrosion became evident, identifying that the zinc/bitumen coated steel wall ties which had been used in the construction of cavity walls deteriorated much quicker than had been anticipated. In 1981 the British Standard for the protection of metal wall ties in construction was amended, and the zinc protective coating was tripled in thickness. Deterioration of cavity wall ties has been found to be a much more serious and widespread problem to walls throughout the UK than was first anticipated, particularly in exposed areas or in walls of particular construction, and with specific mortar types. Possible visual symptoms of cavity wall tie corrosion: • Horizontal and Stepped cracking to masonry/mortar pointing/external coatings. • Bulging walls. • Loose high level masonry. Eroded Cavity Wall Ties in walled Situation Deteriorated C W Ties Up & Under became involved in undertaking the replacement of deteriorated cavity wall ties in the late 1980's. Consequently, we have extensive experience in both inspecting the condition of the existing cavity wall ties, and the undertaking of remedial works where necessary. THE SOLUTION • In order to assess existing cavity wall ties, Up & Under use various types of specialist equipment. High quality metal detectors are used to locate the wall ties within the construction. After location, the condition of the wall ties is assessed using fibre optic boroscopes. • After assessment of the cavity wall ties, Up & Under will put forward a specification for remedial works if required. • In general terms, the remedial work is dependent on the severity of the problem and the specific type of wall tie within the construction. Up & Under have an extensive range of high quality stainless steel remedial wall ties to suit almost every application. Once completed, our remedial works are left to a very high cosmetic standard. New high quality remedial cavity wall ties As an independent contractor, we can select the best product for each particular situation and recommend the best possible remedial action to be undertaken, as and when necessary. Cavity Wall Ties Works undertaken by Up & Under are normally covered by our long-term guarantee. Please do not hesitate to request further information. Freecall: 0800 4581052 or email sales@upandunda.co.uk website designed and constructed by www.outhousemedia.net