When doing a concrete overlay repair good surface preparation is key to a long lasting repair. These pictures show what can happen when you do not prepare a substrate to the correct International Concrete Repair Institute (ICRI) surface profile. We recommend mechanically preparing the substrate to a minimum CSP 5 following ICRI Guideline 310.2R to allow for proper bonding. These pictures show US SPEC TP Mortar delaminating from the existing substrate because of the lack of substrate preparation.