Testing Bond Strength of Masonry

This Digest covers the technical background, the calibration and the interpretation of results for bond wrenches. It features the use of the 5 BRENCH but the principles and methods described are relevant also to standard bond wrenches available on the market. The BRENCH is a BRE development of the bond wrench, an in-situ tool for testing the bond of masonry units (bricks and blocks) to mortar. It is a powerful tool, used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. It is complementary to, but more versatile than, the British Standard Wallette method.