Curtain injections with large wall thicknesses
Companies are again and again faced with the challenge of redeveloping and sealing historic buildings. The particularities which represent both the charm and difficulty of these tasks at the same time – besides the old building materials and designs, missing plans or details – are frequently also the dimensions of the structure or individual structural components.
When sealing such buildings, a great deal of creativity and flexibility in selecting the most suitable materials and methods is therefore required, as was the case during the redevelopment of the Grevesmühlen Malt Factory, one of the most important and largest industrial monuments in Mecklenburg. The building was erected in 1893, when several breweries existed in Grevesmühlen and the Malt Factory, which had been founded in the 1880s, had to be expanded.
During the redevelopment and conversion of the old Malt Factory, around 660m² of basement walls up to 120 cm thick also had to be sealed.
Conventional exterior sealing was impossible due to the existing neighboring building and subbasement in some areas. Curtain injections into the outside of the structural components, are, however, also extremely complex, costly and difficult with large wall thicknesses. Planners and material manufacturers were therefore faced with the question: What to do with a wall thickness of 1.2 sqm. As the masonry was sufficiently porous, it was possible to form the sealing curtain within the structural component instead of within the adjacent soil, especially as its structure and nature were unknown.
In this way it was not necessary to drill completely through the walls, but it was possible to make drill holes up to about 2/3 of the wall thickness in the form of a grid.
This considerably reduced the time required to make the approximately 4,000 drill holes. The injection material also had to be selected to suit the building’s special features. Whereas the slowly reacting injection gel WEBAC® 250 is generally used for curtain injections within the masonry, it was in this case decided to use the acrylate gel WEBAC® 240 due to the masonry's porosity and absorptivity. The injection gel closes the pore structure of the wall and forms a new vertical sealing level within the wall so that the inside of the structural component can dry out.
The use of room dryers accelerates the drying process of the masonry. Such additional measures are recommended especially in the case of large wall thicknesses, because otherwise the masonry would continue to release humidity over a very long period. Following the extensive redevelopment, the factory now houses various shops, boutiques, coffee bars, doctor's practices and the administrative center of the district government.
If you have any questions on curtain injections or gel injections of comparable buildings or on the materials used, please do not hesitate to contact us.