The in-situ measurements for compressive stress in solid unit masonry are estimated using the Flat Jack Test as per ASTM Standard C-1196. This method is developed by adopting Standard RILEM D-2 for measurements of in-situ properties of rock masses. This is a relatively non-destructive method to determine in-place properties of masonry building structures. The Flat Jack Test is suitable for old brick masonry buildings where the development of a remold sample of masonry block is not viable. BSL is now providing this test facility in Pakistan.