Troubleshooting Guide
Most jobsite microcement issues stem from substrate movement, incorrect coat thickness, or applying sealers over residual moisture. Use this diagnostic matrix to identify, correct, and prevent application challenges across the system (MyPRIMER, MyBASE, MyCROCEMENT™, and MyGUARD).
CRITICAL TIMING & SITE CONDITIONS: Before starting, review our
Master Drying & Curing Guide
for mandatory environmental requirements and recoat windows.
Diagnostic & Repair Matrix
1. Poor Adhesion or Peeling
- Symptom: Microcement flakes, lifts, or detaches from the surface.
- Root Cause: Dusty, oily, or unprimed substrate; insufficient drying of MyPRIMER; or applying base coats over a non-bonded substrate.
- Quick Fix: Scrape back loose material to a sound edge. Clean and degrease the area, re-apply MyPRIMER, allow it to cure completely, and rebuild the layers.
- Prevention: Sand* and degrease all surfaces before priming. Ensure MyPRIMER reaches its specified drying window before applying base coats.
2. Mesh Telegraphing (Visible Fiber Pattern)
- Symptom: Fiberglass mesh grid lines or strands show through base or finish coats.
- Root Cause: Mesh placed over dry base material rather than embedded in wet MyBASE (MyBASE powder mixed with MyBOND), or base skim coat was applied too thin.
- Quick Fix: Sand* high spots lightly. Skim a thin coat of mixed MyBASE over the area to encapsulate the mesh, sand* smooth once cured, then proceed to MyCROCEMENT™ finish coats.
- Prevention: Always sink fiberglass mesh directly into the first wet layer of MyBASE, smoothing it fully before applying the second base layer.
3. Unintended Trowel Marks or Ridges
- Symptom: Dark burnish lines, harsh ridges, or uneven surface texture in finish coats.
- Root Cause: Overworking material as it sets, improper trowel angle (held too steep), or applying finish coats too thick. Using a polycarbonate microcement specific trowel reduces the chances of burnishing and are recommended for beginners.
- Quick Fix: Let the coat dry completely. Knock down ridges using 80–120 grit sandpaper* (for base coats) or 120–220 grit (for finish coats). Apply a light skim of MyCROCEMENT™ using consistent, low-pressure passes.
- Prevention: Maintain a wet edge, keep trowel blades clean of dry buildup, and apply thin, tight coats.
4. Hairline Cracks or Structural Fractures
- Symptom: Fine cracks opening up across base or finish layers.
- Root Cause: Substrate flexing/movement, unjoined seams, skipped mesh in high-stress zones, or coats applied thicker than recommended.
- Quick Fix: Confirm substrate movement has stopped. V-groove the crack, fill with mixed MyBASE, embed a mesh patch across the repair, sand* smooth, and re-skim.
- Prevention: Always secure the substrate and embed mesh in MyBASE over board joints, backsplashes, and high-stress areas. Respect layer thickness limits.
5. Sealer Haze, Clouding, or Spotting
- Symptom: White film, dull patches, or water marks appearing on the sealed finish.
- Root Cause: Applying MyGUARD over damp MyCROCEMENT™, heavy pooling during application, or liquid exposure before full cure.
- Quick Fix: Lightly sand* the clouded area with 220-grit sandpaper* to break the sealer layer. Allow trapped moisture to evaporate, then re-apply a light, even coat of MyGUARD.
- Prevention: Verify MyCROCEMENT™ is completely dry before sealing. Roll MyGUARD uniformly using a short-nap roller without letting sealer pool in low spots.
Download Printable Diagnostic Sheet
Troubleshooting & Field Fixes Guide – PDF — Keep a laminated copy on-site for rapid issue identification.
*PPE & Cleanliness Notice: Sanding and mixing powders create airborne dust hazards. Always wear appropriate personal protective equipment (PPE), including a fitted dust mask/respirator (N95+), protective eyewear, and gloves. Use adequate ventilation or active dust extraction. Wear suitable footwear to avoid transferring dust outside the work area.