CrackWeld DIY Concrete Floor Repair Kit (4-Pack) - Repair Concrete Cracks in Basements, Driveways, Garages, Patios, & Pool Decks Permanently repair cracks in concrete floors and slabs (hairline up to 1/2 inch wide) No need to route the cracks prior to application Fills the full depth of the crack and cures as a rigid compound that is stronger than concrete Complete kit includes all materials needed - you only need a standard caulking gun