Quick Repairs: Jetcem Rapid Repair Cement is a cement-based product that is easy to use and sets in approximately 30 minutes. Repairs Cracks and Holes: Fills up to 25mm in one application (for deeper fill use Jetcem Rapid Setting Sand & Cement). Internal and External Use: Seals and repair cracks and holes in both internal and external environments. Fast Setting Properties: Fast setting properties suitable for repairs to concrete, stone and brick substrates Before applying, ensure surfaces are clean, sound and free from dust, crumbly material or any contaminants which may affect adhesion.