Embedded steel has been used for strengthening structures for hundreds of years. Embedded steel is particularly common in historic and heritage buildings, often as a structural frame (I beams and columns) or to secure masonry blocks (steel dowels, pins and cramps).

Unfortunately, with time, corrosion of the embedded steel can cause unsightly staining, cracking, or, in extreme cases, failure. For historic buildings, as-built drawings or records are not usually available. The first problem is to identify the type, quantity, and location of any embedded steel.

GPR surveyor scanning listed building facade to locate embedded metal
GPR scanning to locate embedded metal in a listed building

Sandberg undertakes embedded metal location and investigation surveys using GPR and other detection techniques. The main advantage of GPR for this type of survey is that it will detect all metals, not just ferrous metals. GPR will also provide information about the depth and often an indication of size and section.

GPR can also help determine construction detail and thickness and detect other features like voids.