Slightly widen the crack and seal with the polyurethane sealant DUROFLEX-PU, after priming with PRIMER-PU. Next, to waterproof and aesthetically restore the area, apply the acrylic elastomeric waterproofer DUROSTICK No39 in roof tile color over the entire surface of the drainage gutter.
Alternatively, seal with dB BLOCK at a thickness of 3mm and apply DUROSTICK No39 in roof tile color. An excellent solution is also the application of the flexible cementitious sealant DUROFLEX POWDER (roof tile color) in 2 to 3 consecutive coats of 1-1.5mm thickness each. On friable substrates, priming with the micromolecular stabilizer AQUAFIX is recommended.
