St. Martin Cathedral, originally Gothic sacral building in the historical zone of Bratislava, is the most important and largest church in our capital city. It is one of the most prominent Bratislava landmarks and after the Bratislava castle the second most popular tourist locations. Its construction started in the 13th century on the land of an older cemetery, which previously was a smaller chapel. It shaped itself during several centuries and its present look came only in the 1849th
St. Martin’s Cathedral is a three-aisled hall-type building with central ship, two lateral ships and pre-built presbytery. The building is oriented in the direction west-east. On the west side of the building there is completed built prismatic tower which is the dominant architectural element of the temple. The church tower was originally built as part of city walls served as stronghold. In 1760 it was destroyed by lightning and replaced with the new building which did also not sustain long. Tower church succumbed a devastating fire in 1833 and was restored in neo-Gothic style with gilded pillow and a copy of the Hungarian royal crown on top. With its height of 87 meters it is the highest church tower in Slovakia. On the facade of the bell tower there is located above the broken windows four clocks. Since 2002, St. Martin’s Cathedral is a national monument.
Reconstruction and rehabilitation
The last reconstruction that building went through over the past year had to do with the care and restoration of plaster facade of the tower and west facades. After solidification of sand and weathered plaster primer based on water glass created the contact bridge has been applied to the façade plaster to level the background and large inequalities. The final layer is made of the historic plaster dyed through the substance of two different granularity. Fine-effacement in the top level of the tower is without any cracks, the bottom of the tower and west facade with significantly different coating is fully stable but locally occurring small cracks due to the method of extinguishment and tension applied at the very outer layer of the historic plaster. The final coating meets the state requirement and historic monument preservation. Relatively large inaccuracies and inequalities of the original plaster were removed entirely and preparation of the substrate as well as individual plaster layers returned to the surface are made very well, creating a long-term guarantee of quality and stability.
Historical plasters Baumit HR 810 870 WX with grain size of 0-1.2 mm and Baumit HR 810 880 with a grain size of 0-4 mm, which were used in the reconstruction of the façade of St.Martin’s Cathedral, very appropriately complement the range of plaster mixtures intended for the rendering of difficult surfaces of historic buildings. Whole series of historical plasters Baumit HR, developed specifically for the area gets into awareness of not only designers, authorities of historic preservation, but especially restoreringand expert implementation companies that are interested to perform quality work with long-term life. It is indisputable that without quality material such a solution would not be possible.
That is why the problem of suitability of original solutions is so current, and the requirements for unifying identity are even higher. The suitability of products Baumit HR for both manual and machine processing is added by a wide range of possibilities of techniques of definitive interpretation. Rough application, the extinguishment with a spoon or wooden float, sponge or polystyrene float. And not just the size and orientation of moves, but also pressure on the background, in full security and coverage to viscosity limits at sharp roughening of the surface to the opening limit of application of the plaster. The result is a requirement of the required adjustments and plaster dyed through the substance represents in the final solution in its complete expression the compact and determining character of prevailing of dominant age.
Materials with the highest demands
Strength class 1.5 to 5.0 N / mm2 ranks the plaster that was used in the reconstruction of St.Martin’s Cathedral, to the softer coat. By incorrect application of very hard plaster and diffusely enclosed plasters in the surface layers of historical buildings and disrespecting the laws of building physics and mechanics (sorption properties of plaster, ensuring the moisture transport…) are the reasons of volume changes that lead to a gradual separation of plaster from the background.
Specifically important today appears to be the plaster resistance to dirt due to the environment in the form of acid rain, cushioning, impact changes in heavy rain or whirlwinds. Less weak, very high porosity and strongly demineralized surfaces are not able to withstand the load. The degradation process is then accelerated to total separation of plaster from the background.
Baumit plasters HR represent a perspective group of plasters, which is suitable to be classified in the compound of claddings of historical buildings. Meeting the requirements of monument restoration and protection as the primary goal of reconstruction is reflected in the plaster behavior that is specified for a particular cladding while still considering the special situations of the facility and is secondarily fleshed out
St. Martina – mended plaster facade of the tower and west facades
Owners and investors :
Thanks for close cooperation Regional Monuments Office in Bratislava, represented by Mgr. Marta Belohorcová
Text: Cooperation with Baumit (Ing . Jozef Bak , PhD.,) Chief technology monument restoration officer .