The depth we can scan into concrete depends on the method used and the condition of the concrete. Ground Penetrating Radar (GPR) typically penetrates up to 300-400mm in dense concrete, and potentially more in dry, low-rebar environments. However, high moisture content, dense reinforcement, or steel mesh can significantly reduce penetration. Ultrasound (pulse velocity) can provide depth readings up to 1 metre or more, but is more limited when the concrete surface is rough or uneven. We always assess the site conditions and select the best technique accordingly.