Which methods are suitable for thick brick walls with moisture penetration?
In the case of large cavities/voids in masonry, the voids are first filled to prevent uncontrolled drainage of the injection material. Injection resins can then be applied to create a continuous damp proof course (dpc), providing the masonry with lasting protection against moisture. An example of this can be found in the project report on the renovation of a bank building in Rzeszów.
Which methods are suitable for very thick walls?
For very thick walls, curtain injections within the wall cross-section are suitable, as they enable continuous sealing even with thick walls. The pore structure of the wall is sealed with an injection gel, creating a new sealing layer and allowing the basement walls to dry out from the inside. A practical example can be found in the project report on the renovation of the Grevesmühlen malt factory.
Do post-construction damp proof courses also help with salt efflorescence?
Yes, post-construction damp proof courses can also be effective in salt-contaminated masonry. The targeted injection of resins permanently prevents capillary moisture transport, significantly reducing the moisture level even in heavily damp and cavity-rich masonry. You can find an example of this in the project report on the renovation of an old building's basement.
How can buildings with salt-contaminated masonry be protected?
Buildings with salt-contaminated masonry can be protected by surface sealing, which prevents moisture ingress while remaining permeable to vapor. This allows residual moisture to escape without causing further damage, while the building fabric remains stable in the long term. Examples can be found in the project reports on the renovation of the La Palma Astronomical Observatory and the city wall in Potsdam.
Suface Sealing Observatorio La PalmaSurface Sealing City Wall Potsdam
How are large cracks sealed?
Large cracks, such as those found in parking structures, are repaired using a crack injection process: The cracks are first widened into a wedge shape, cleaned, the edges are taped off, and then saturated with epoxy resin until completely saturated. This restores the structural bond in the concrete and creates the basis for a new, load-bearing coating. You can find an example in the project report on the renovation of an underground car park and in a video about the work carried out.
What categories are there for crack repair?
The following categories are distinguished in crack repair:
CATEGORY D
Expandable crack filling materials
For limited expansion filling, structures are required that do not cause the crack filling material to tear even when subjected to expansion and compression movements across the entire crack surface.
CATEGORY F
Low-viscosity, solvent-free epoxy injection resins are predominantly used for structural bonding (filling). The good spreading and flow properties of these crack filling materials enable the injection of cracks with crack widths > 0.1 mm and penetration into the finest ramifications. Structural bonding can also be achieved with some PU resins.
CATEGORY S
Elastic and swellable acrylate gels are used to seal component joints and protect components against water ingress or pollutants (e.g., chlorides). These products are characterized by good penetration properties, high flank adhesion, and adjustable reaction times.
