This is why we do our due diligence and thoroughly examine every sample that comes into the lab. This is from a church built in 1776. At first glance it all looked the same, but after review even the original joint profile was discovered! Note the width of the original mortar too. It shows a more refined and thinner joint. The Portland Mortar was then installed over the arris and onto the face of the stone. Did I mention we offer this service for free?! Check out our full list of services!