Preparation of groove parts of internal masonry basements

Especially at the groove part (angle between concrete slab/basement wall), where several building components meet, there is often the highest moisture load. Because this area is the lowest part of the building and is situated near to water location. Their old coverings, screed and render must be removed in general. Also, the damaged joint mortar network must be scraped out at a depth of up to 2 cm. The aim is to achieve a load-bearing substrate with open capillarity, with which the new waterproofing can have a good key. For the preparation works, best practice is to use sand-blasting with solid particles and substances. The choice of an appropriate preparation method depends on the type of substrate and the chosen waterproofing system.

Simple & safe to the goal

  1. 1. Carry out the waterproofing in a trough shape. Each waterproofing layer/section must overlap by at least 20 cm. Existing coverings, screed and render in transition areas with the wall, are to be removed.

  2. 2. Chisel a recess of 4 x 4 cm in the angle between the concrete slab and basement wall; it will provide a good key for the following watertight mortar weber.tec 933 with the substrate.

  3. 3. The recess, in the area where a bitumen sheet is laid (usually in the first masonry row), will impede the uprising damp between waterproofing and masonry.

  4. 4. In connection with binding cross walls (for ex. inner walls) with outer walls a complete separation of the transversal wall can be carried out, in order to obtain a throughout internal waterproofing (without "break").

  5. 5. Ensure that all necessary slots are done for installations to be fixed in the wall-cross sections prior to waterproofing works so that the waterproofing layers can be applied behind the installations.

  6. 6. Alternative: also a vertical damp-proof barrier as capillary waterproofing with the silicone micro-emulsion horizontal damp-proof barrier weber.tec 940 E or the silane-based injection cream weber.tec 946 can be installed in this area.