The objective with the present project was to combine studies of textbooks and masonry constructions with laboratory analyses of historical mortars from the time period 1800 to 1950. The objective was to investigate the development of knowledge and craftsmanship of the mason during this period. The three different sources display the same trends from binder rich to binder poor and to mortars based on cement and lime mixes. There was a change from a complex and varying use of different mortars in the 19th century to a simplified and standardized use in the 20th century. This process also includes a change to a centralised and industrialized production of binders. A consequence of this was that a loss of the craftmans knowledge of how to handle different hydraulic binders and pozzolans. The later part of the period was characterised in a loss of knowledge in this aspect for all actors working with masonry and renders.