Written by Stucco Champions — Southern California’s Authority on Exterior Plastering.

Is It Possible to Grind Stucco? A Guide to Surface Correction

Stucco is designed to be permanent. Once it cures, it is essentially rock. But what happens if the texture is too rough, or a previous patch job left a visible hump on the wall? Homeowners often ask: "Can I just sand it down like drywall?"

The answer is No, you cannot sand it. But you can grind it.
Grinding stucco is a heavy-duty process that requires diamond-tipped tools and strict safety protocols. It is not a standard maintenance task; it is a corrective measure for bad application. This guide explains the machinery and methods used to flatten a stucco wall.

1. Why Grind Stucco?

We typically grind stucco in two scenarios:

• High Spots: When a patch repair was not feathered correctly and sits "proud" (higher) than the surrounding wall.
• Texture Changes: When a homeowner wants to convert a heavy "Spanish Lace" texture to a smooth finish, we must knock down the peaks before applying the new smooth coat.

2. The Tool: Diamond Cup Wheels

Standard sandpaper will disintegrate against cement. To remove stucco, you need an Angle Grinder fitted with a Diamond Cup Wheel.
These wheels are metal discs studded with industrial diamonds. They spin at 10,000 RPM and eat through cement instantly.

3. The Danger: Silica Dust

Grinding stucco releases a massive cloud of silica dust. This is a known carcinogen and lung irritant.
Safety Protocol:
1. Respirator: You must wear an N95 or P100 mask. A paper dust mask is insufficient.
2. Dust Shroud: Professional grinders are equipped with a vacuum shroud that sucks the dust directly into a HEPA vacuum. Grinding without a shroud will coat your entire neighborhood in white powder.

4. The Technique: "Feathering"

The goal of grinding isn't just to make it flat; it's to blend it.
Hold the grinder flat against the wall. Do not tilt it on its edge, or you will gouge "half-moon" cuts into the stucco. Move in circular motions, gradually working from the center of the high spot outward to feather the edge into the existing wall.

5. Post-Grinding Repair

Grinding leaves the surface smooth and open-pored. It will look different than the surrounding texture.
The Fix: After grinding, you almost always need to apply a new Skim Coat or Fog Coat to restore the finish and seal the surface. You cannot just paint over raw ground stucco; it will absorb paint unevenly.

Conclusion: A Last Resort

Grinding is effective, but it is aggressive. It removes the waterproof finish coat, exposing the brown coat underneath. Only grind if you plan to re-coat the area immediately. If you are unsure, consult a professional to see if a "build-up" skim coat is a better option than grinding down.