The flooring samples arrive in a handsome box. The slab underneath has a crack nobody has discussed yet. It is tempting to let the new floor settle the conversation.
Record what the crack is doing
MAPEI's substrate requirements distinguish preparation from slab movement and moisture issues. Photograph the crack, note any height difference or dampness, and have uncertain conditions assessed before selecting the flooring system.
Match the repair to the finish and the problem
Ask what each proposed product is intended to do: fill a void, prepare a surface, isolate certain movement, or address moisture. Those are separate functions. Do not fill every intentional joint simply to make the concrete look continuous. Keep the repair compatible with the chosen adhesive, underlay, and flooring instructions.
Before the next step
- Photograph cracks before grinding or filling.
- Flag displacement, active change, and moisture.
- Get a compatible written preparation specification.
Keep the crack visible until the assessment and compatible repair plan are settled. Then you can choose the finish with fewer unanswered questions. Compare carpet with more inspectable finishes once the slab is understood.