M02.03
Prep, moisture, and why floors fail
The unglamorous science that protects warranties — and the admin's job when numbers go red.
- Explain CSP and why prep is a line item
- Know what to do with a high RH reading
- Treat dew point as a stop-work condition
What 'prep' means when we say it
Concrete is not a clean canvas. It has laitance, oils, curing compounds, old coatings, cracks, and moisture vapor. We mechanically prepare to a specified Concrete Surface Profile (often CSP 3–5 for resinous systems) by shot blast and/or grind, then handle joints, cracks, and details. Admin must never let a GC delete prep to 'save a week' without a written, priced, Eric-approved change — which we will usually refuse.
Red-flag readings and words
| Signal | Admin action |
|---|---|
| In-situ RH (ASTM F2170) or calcium chloride backup (F1869) fails the system limit | Stop sequence. Document. PCO for mitigation or wait. No hopeful applications. |
| Oil, unknown coating, or 'we think it's clean' | Photo, hold, estimating / field lead. |
| Dew point / condensation / 'slab is sweating' | Treat as stop-work. Note weather on daily report. |
| Soft concrete, scaling, hollow sounds | Do not pretend. Extra repair is extra money and time. |
Takeaways
- Prep is the job. The coating is the finish.
- Record the number. Do not editorialize it away.
- Warranty language dies in undocumented moisture.