Horizontal cracking in brickwork, external rendering or building blocks can often be caused by the failure of cavity wall ties. These are metal restraints that prior to 1978 were manufacture from galvanised steel. They were expected to last the lifetime of the building but it was found that some corroded after only 15 or 20 years. When the ties corrode they expand to several times their original thickness, which causes the wall to crack at the mortar joints and often result in major damage and sometimes collapse of the wall.

Our qualified surveyor will carry out a survey using a metal detector, borescope and damp meter and by drilling into the wall at appropriate intervals he will view inside the cavity to check for wall tie corrosion. He will also determine the extent of any external cracking and advise you of any appropriate repairs that are required or if the services of a structural engineer are needed. We will then issue a detailed report, our recommendations and estimate for all necessary wall tie replacement and remedial work.

Tapco Cavity Wall Ties

We use a double expansion remedial wall tie that is manufactured from corrosion resistant Austenitic 304 grade stainless steel tie bars with Neoprene sleeves. These have a unique ‘tall-nut’ which when turned with a setting tool, rotates the whole tie bar, forcing the inner leaf sleeve to open and grip the masonry. At a factory set torque level, the end of the ‘tall nut’ shears away and the remaining nut is forced down the bar to expand the sleeve and grip the outer leaf.

Guarantee

Procedure