Clay Wash Interior Wall Application

Preparation, Substrates & Best Practices

Proper application is essential to achieving the full aesthetic and performance benefits of clay wash. While clay wash is forgiving compared to some mineral finishes, it still requires correct surface preparation and specification

Suitable Substrates for Clay Wash

Clay wash performs best on:

• Clay plaster

• Lime plaster

• Mineral-based plasters

• Properly prepared cement plaster

Gypsum surfaces can be used with appropriate mineral primers

Surface Preparation

Before application, walls must be:

• Clean and dust-free

• Free from synthetic sealers

• Lightly absorbent

• Structurally sound

Surface preparation directly affects adhesion, appearance, and long-term performance

Priming Requirements

Mineral or clay-compatible primers are recommended to:

• Regulate surface absorption

• Improve adhesion

• Ensure consistent finish

Using incompatible primers can block breathability and compromise performance

Application Method

Clay wash is typically applied in:

• One or two thin coats

• Using brush or roller

• With cross-directional strokes

Natural hand movement is part of the aesthetic, and uniform perfection is neither expected nor desired

Drying and Curing

Clay wash dries through:

• Water evaporation

• Physical bonding

Adequate ventilation and moderate temperatures support optimal drying and finish quality

Common Application Mistakes

Avoid:

• Applying over sealed or glossy surfaces

• Overworking the surface

• Using incompatible primers

• Expecting uniform color like synthetic paint

Quality Control and Specification

For architectural projects, proper specification ensures:

• Predictable results

• Consistent appearance

• Long-term durability

Mock-up panels are recommended for large or high-visibility projects.

Correct clay wash interior wall application ensures that both aesthetic and performance benefits are fully realized. With proper preparation and execution, clay wash delivers reliable, high-quality results for modern interior architecture.