During my usual run yesterday, I passed by the ongoing library expansion. The workers were tiling the exterior entrance with what looked like standard thin-set. From my experience, that mortar isn't suitable for the large porcelain slabs they had stacked nearby. This is a common error that causes tiles to detach over time, especially with foot traffic. It's irritating to see such a basic oversight on a public building. They're essentially creating a future repair headache for the city. As a tile setter, it's hard to watch without intervening.