A sound preparation plan identifies the substrate, removes weak or incompatible material, creates a consistent profile, cleans thoroughly, and repairs defects with materials chosen for their depth and movement.
Mechanical profile, not cosmetic scuffing
Mechanical preparation creates the specified surface profile and removes unsuitable surface material. Cleaning contamination must be addressed before profiling rather than assumed to happen through grinding alone. The equipment, tooling, passes, edges, and dust collection should match the hardness and condition of the concrete.
Acid etching is not an equal substitute on every floor. It may react unevenly where oil, sealers, paint, or hard-troweled areas are present, and it adds rinsing and neutralization variables. See diamond grinding versus acid etching for the decision factors.
Repair cracks according to behavior
A narrow dormant shrinkage crack is different from a moving joint, settlement crack, or broken edge. Cleaning, routing, filler stiffness, repair geometry, and finish treatment should reflect that difference. A coating can make a repaired crack less distracting, but it cannot stop the building from moving.
When displacement, recurring movement, or structural concern is visible, pause the finish decision and seek the right concrete or engineering review.
Contamination and moisture require evidence
Oil can penetrate beyond the dark mark seen at the surface. Existing sealers may be nearly invisible. Moisture vapor may be active even when the floor looks dry. Preparation should include inspection and, where risk supports it, testing or test patches.
No single field test predicts every future condition. The goal is to reduce unknowns, select compatible products, and document assumptions before the floor is covered.
What to document before coating begins
Photograph cracks, joints, drains, patches, thresholds, and contamination before moving items. Record which features will be filled, which remain visible, and where a repair may telegraph. Confirm whether the coating stops at the garage door, continues onto the apron, or turns up walls.
A written substrate map is especially useful in commercial work and older garages because it creates a baseline for later inspection.
Common questions
Does grinding remove every oil stain?
Not always. Oil can penetrate into concrete. Ask for a documented cleaning and acceptance plan. If contamination remains, the system designer must decide whether affected concrete can be treated or requires removal.
Should control joints be filled?
It depends on the joint’s purpose, expected movement, traffic, and desired appearance. Filling a moving joint rigidly can lead to cracking. The proposal should state which joints are filled or honored.
Can grinding make a wavy slab flat?
Surface preparation creates profile and removes weak material; it is not the same as leveling. Correcting slope or major flatness problems is separate concrete work.
Bring the unanswered items into your inquiry
This guide is a planning aid. Ask the installer to identify the current product requirements, verify the concrete and document any unresolved condition before agreeing to the system. The references below provide context; their requirements apply to their named products or procedures.
Use the moisture-test record checklist, oil-contamination questions, and threshold and drain detail schedule where they match your floor.
References behind this guide
Technical limits apply to the named product or test. Confirm the current requirements for your proposed system.
