The influence of craftsmanship on the inner structures of lime plasters

Paper in proceeding, 2005

The use of traditional lime plaster in restoration of old buildings is motivated by both technical and historic reasons. The plasterer deals daily with a multivariable problem where the variables are related in such a complex way that we are not even close to finding converging solutions by traditional scientific methods. The decisions and actions of the craftsman will have an influence on both the surface structure and the inner structure of the lime plaster. The present paper will focus on the time between application of mortar and working on the surface to make a floated finish. In total, 32 lime plaster surfaces have been analysed. Half of them have been worked on after they have stiffened up and half of them have been worked on while they are still fresh. The results clearly show that the time between application of mortar and working the surface is a critical parameter. If you wait until the right time, you receive a more homogeneous and compact material with an open surface and a higher frost resistance. Keywords: lime, plaster, pore structure, frost damages, craftsman