Substrate check and preparation for renovation works indoors

A prerequisite for successful renovation is a prior survey and analysis of damage. One of the most important investigations is the recording of the type, thickness and characteristics of the existing masonry.

Examinations of the moisture on internal and external walls at different heights provide important information on the causes of the moisture damage. Such information is necessary in order to set up an appropriate renovation concept. This also includes recording data about the permeability of ground and hence which water load is prevailing.

Step by step


    1. The floor damp rises in a capillary way into the masonry. The horizontal damp-proof barrier is defective or non-existing.


    2. A prerequisite for large-size successful renovations is a comprehensive analysis of the conditions of the concerned building parts. Masonry samples are taken with the drill core device and sent air-tight packed to a laboratory.


    3. The laboratory will check the degree of moisture of the masonry samples (precisely ratio between actual moisture content and saturation moisture) and the salt content on the samples. This information will help to set up the renovation concept.


    4. Remove the old render at least 80 cm above the damaged and salt-loaded area


    5. Chisel a recess of 4 x 4 cm in the angle wall/floor. As a rule, a watertight and shrinkage-compensated mortar, for ex. weber.tec 933 must close this area. Thanks to its bonding strength it must be resistant against the backwards water ingress.


    6. Scrape out the brittle joint mortar network in a depth of 2 cm.


    7. Ventilation or other room drying measures with appropriate devices are helpful for drying of the moist masonries.