1. Clean the damaged locality of the siding with a cleaning solution of 1/2 cup trisodium phosphate and 1 gallon of water. Use a supple bristled brush to clean the cracked locality, removing all dirt and debris from the damage location. Rinse the siding with clean water to remove soapy residue.
2. blend the latex-modified cementitious patching compound according to the manufacturer’s directions in a little bucket. The consistency of the compound should be rigid sufficient to contain on the tip of a putty knife.
3. Fill the crack with the compound utilizing the brim of the putty blade. Push the compound solidly into the chink. somewhat overfill the chink with the aggregate. Scrape the exterior of the chink with the edge of the putty blade to grade the aggregate with the surrounding surface.
4. Wait three hours for the compound to cure. Keep the exterior of the aggregate moist by squirting it with a mist of water if it starts to dry. permit the compound to therapy for 24 hours.
5. decorate the patched locality the identical color as the rest of the siding in order to blend the patch in with the surrounding cement fiber exterior. permit the decorate 48 hours drying time before moving the surface.
Hope this helps.