This article walks through how to apply Earthaus Base Finish, from substrate preparation through both coats, along with care and repair guidance. It is a summary of the official Earthaus Base Finish Application Guide, adapted for clarity and ease of reference. To view the full document, see the Earthaus Base Finish Installation Guide (PDF).
What Is Base Finish?
Earthaus Base Finish is a coarse, matte interior lime plaster.
Unsealed and absorbent. Not suitable for showers or wet areas.
Named for its raw texture and commonly used as a base for other finishes.
Materials Summary
Total system thickness: 1/16" – 1/8"
Two coats of Base Plaster
Primer Grit: Additive used with any PVA or latex primer on level-4 drywall or painted surfaces
Mineral Pigment: One Pigment Pack per bag of Base Plaster (optional)
No sealing required, but Olive Oil Soap Sealer may be applied optionally for stain resistance
Properties
Made from US-quarried lime, pumice, and plant-based binder
Optional mineral pigment
100% natural, breathable, mold-resistant
Absorbs CO₂ and re-carbonates into limestone
Zero VOCs or chemical additives
Highly workable and durable
Where Base Finish Can Be Used
Suitable for:
Interior dry wall surfaces
Feature or architectural texture walls
As a finish on its own or under other finishes (e.g., Tadelakt)
Not suitable for:
Showers, wet areas, or anywhere moisture resistance is required
Exterior application
Substrate Preparation
Approved substrates:
Level-4 drywall
Previously painted drywall (must be clean and dry)
Any surface primed with PVA or latex primer + Earthaus Primer Grit
Primer instructions:
Use PVA or latex primer (zero or low VOC preferred).
Add 1 cup Primer Grit per 1 gallon of primer.
Mix 30 seconds with drill + paddle.
Apply 1 even coat with roller or brush.
Allow to fully dry.
Application Sequence
Substrate prep (priming with Grit)
Base Plaster Base Coat (1/32–1/16")
Base Plaster Finish Coat (1/32–1/16")
Mixing Instructions
Add 2 gallons of water to a 5-gal bucket.
Add full Pigment Pack (optional); mix 1 min with high-RPM drill.
Strain pigmented water through 5-gal mesh strainer.
Add Base Plaster in 1/3 increments, mixing and scraping sides each time.
Final mix: 3 minutes minimum with high RPM.
Adjust water slightly if needed (aim for thick milkshake consistency).
Coat Details
Base coat:
Apply evenly at 1/32–1/16" per coat.
At ~60% dry, smooth ridges with clean trowel.
Let dry fully before finish coat.
Color lightens significantly when dry.
Finish coat:
Apply "tight coat" slightly thicker than aggregate grains.
When firm but damp, double back with second tight coat.
Optional: Add textural effects while wet using tools.
Optional: Light burnishing while semi-dry for smoother finish.
Tips & Common Issues
Even base coats: Prevent high spots/ridges to avoid color inconsistencies.
Coat thickness: Thicker coats increase cracking risk.
Burnishing: Too much pressure can bruise and darken finish.
Color variation: High spots/ridges are more prone to discoloration.
Care & Maintenance
Cleaning:
Unsealed finish is absorbent — do not wash with water.
Use vacuum or dry dusting.
Optionally seal with Olive Oil Soap Sealer for better cleanability.
If sealed, follow Earthaus Stone Finish cleaning guidance.
Repairs:
Staining: Superficial stains: light sanding with fine abrasive cloth or sandpaper; deep stains: spot patch or recoat full wall.
Hairline cracking: Often from substrate movement; can be patched, but may remain visible if movement continues.
Chipping: Most common on outside 90° corners; repair by filling with Base Plaster.
Storage & Disposal
Storage: Mixed: up to 14 days, covered at room temp (remix with drill before reuse); Dry: up to 1 year if kept dry with low humidity.
Disposal: Let excess plaster fully dry in container; discard dry material in regular trash.
Tools List
Category | Tools Needed |
Substrate Prep | Drill, small mixing paddle, roller or brush |
Mixing | 1200 RPM drill, egg-beater paddle, mesh strainer |
Application | Hawk, trowel, scraping knife |
Project Consultation
Earthaus offers technical consultation with experts for project-specific questions.
© 2025 Earthaus Plaster LLC.
Still Have Questions?
Email [email protected] or text 1-800-917-2414.