In June-September, with the agreement of the architect and the contractor, the project team participated as observers in several tests carried out to clean a facade of a similipierre brickwork. This involved dry blasting with different materials, wet blasting with water jet at various temperatures and pressures.
The observations made, combined with the literature research, show that in the case of dry blasting, low pressure and the least abrasive materials are recommended (in this case calcium carbonate was used). Pressure washing highlights microcracks in the surface of the plaster and raises questions about over-saturation of the plaster and masonry from the amount of water sprayed at very high pressure. Thick accumulated dirt is difficult to clean, either at very high pressure or by insisting a lot with the cleaning jet (wet or dry) leading to uneven surface erosion.
During the summer, the project team also started the analysis and interpretation of the first analysis results from collected plaster samples.Three different laboratories were contacted, one of them from the University of Applied Arts in Vienna. The first observations are related to a wide variety of composition (binder-aggregate ratios). The types and quality of the cements used are aspects that require more detailed and in-depth understanding and investigation.
Thanks to our partners: Kerakoll, Remmers, Timis County Department for Culture
Thanks to Polarh architectural office and Erbașu firm for the access to the restoration site of the University Palace in Bucharest
“Forgotten Textures – Historical Plastering. Research and practical studies for repair and maintenance” Project in phase II carried out by Pro Patrimonio Foundation and supported by the Romanian Order of Architects from the Architecture Stamp Tax and PSC Group.