Specialist applications in the Czech Republic
Sedlec & Český Šternberk - Czech Republic
The Czech Republic is rich in historic buildings. However, their maintenance constantly brings with it challenges due to the sometimes conflicting interests of restoration and heritage preservation. And it is here that Oxal and EXZELLENT come in as the ideal solution-providers. These two repair systems from MC are specifically aligned to the needs of old buildings and historic structures.
EXZELLENT at work
Located in Bohemia some 70 kilometres from Prague, Sedlec is a preserved medieval district within the town of Kutna Hora. With extensive direct ground contact, the masonry of its Cathedral of the Assumption of Our Lady, built in the Middle Ages along the lines of French models, was extremely damp and exhibited heavy algae growth. Chemical removal was ruled out as a solution to this problem, which meant that repair was unavoidable. The client, the Parish of Sedlec, agreed with a recommendation made by MC sales representative Lukas Pecenka to use the EXZELLENT system from MC. This moisture-regulating render can be applied onto the moist substrate without the need for prior drying.
It then ensures that the moisture is absorbed from the masonry and discharged into the air. The work was carried out in 2014. After the old render had been chipped off, EXZELLENT 520 was used as the spatter coat and bonding bridge, with EXZELLENT 610 then being applied as the final coat. Characterised by its mould-inhibiting effect and long service lifetime, this system structure is also resistant to flood waters, splash water and driving rain. The client was entirely satisfied with the outcome, with MC having put itself in pole position for further tasks of a similar nature.
The cemetery in Sedlec features a legendary chapel from the early 15th century, the basement of which has long been used as an ossuary, the final resting place of the skeletal remains of over 40,000 people. The high nitrate content in the damp ground of the still operational cemetery had, in particular, taken its toll on the chapel’s fabric. There were also problems with cracks in the old masonry and in the support columns. The ossuary therefore had to be repaired. Here again, the specimen surfaces prepared by MC and the wide range of requirements covered by the Oxal system convinced the Catholic Parish of Sedlec to opt for the MC solutions suggested.
The cracks in structurally relevant locations were repaired using helical steel reinforcement in combination with the anchoring grout Oxal AVG-QM to provide the rigid fill – sealing with epoxy resin was not allowed due to heritage conservation regulations. The rising damp in the masonry was combated with a horizontal barrier of Oxal HSL, while particularly dilapidated areas with seeping water were restored with the highly sulphate-resistant barrier mortar Oxal SPM. And last but not least, the damp and nitrate-contaminated masonry was rehabilitated with the proven moist-ure-regulating render EXZELLENT.
EXZELLENT again proved its credentials in the repair of Český Šternberk Castle some 40 kilometres south-east of Prague. The solid castle masonry was very damp and exhibited a high salt content due to the presence of faeces in the area of the earlier stables. The specimen surfaces prepared by MC convinced the castle owners to such an extent that here too
EXZELLENT and EXZELLENT historic, the world’s first cement-free moisture-regulating render, were extensively utilised. In all three projects, MC was able to impress with convincing integrated solutions, ably backed up by the reliable advisory skills of Lukas Pecenka.