Is the laser cleaning of historical stone cost-effective?

For the laser cleaning of Gotlandic sandstone monuments by means of surface ablation the advantages are experimentally confirmed and the expense factors of this laser application are compared with their counterparts of the conventional restoration technique. Results indicate for the case of commercially available, Nd:YAG, Q-switched laser systems that the laser cleaning represents an efficient, fully controllable and selective tool for conservator’s practice. Depending on the system applied the expenses in the range of 0.17-0.45∈per dm2 of the laser-cleaned surface are lower by an order of magnitude than these of chemical and mechanical methods.