BUILD Interior Products Overview

Three Coat Plaster System

BUILD Products | Interior

Earthaus BUILD products are formulated to support the unique requirements of earthen and bio-based architecture. Designed to function seamlessly with natural building substrates, BUILD plasters provide exceptional compatibility and lasting performance while safeguarding the structural integrity of your project.

For detailed information about the BUILD Plaster System for your specific substrate, refer to:

Wall Systems Guides

PHL Binder (Pozzolanic Hydraulic Lime)

Use for the Scratch + Brown Base Coats

Made with hydrated lime and pumice pozzolan, Earthaus PHL Binder requires the addition of locally sourced sand aggregate and water.

Size : 50 lbs / bag
Cost: $45 / bag

Coat Thicknesses & Coverage
The standard scratch + brown coat thicknesses are unique to each natural building substrate. Actual coverage may vary based on the condition of your substrate. Please Refer to your Wall System Guide.

Added Sand Aggregate:
Locally sourced sand aggregate is a critical component: it provides structural integrity, increases the volume of the plaster, and helps to reduce shrinkage during drying. The quantity of sand that is added the scratch + brown coat mixes differs. A thorough guide to sourcing sand is provided in the PHL Binder Installation Guide.

Scratch Coat Application: The scratch coat functions to create a mechanical bond to the substrate and give texture (tooth) for the brown coat. The scratch coat is horizontally scratched with a scarifier tool.

Brown Coat Application: The brown coat functions to build the plaster to a uniform level and create the final shape of the walls.

To Order: Use the calculator to select your substrate + enter your project square footage to calculate the quantity of PHL Binder needed for a project. The calculator will show separate calculations for both scratch and brown coat quantities.

Product Page & Calculator

INTERIOR LIME PLASTER - SAND & STONE FINISHES

Two Texture Options

Made with hydrated lime, pumice pozzolan, and carefully selected aggregates, Sand and Stone Finishes require the addition of water and can be pigmented in any standard Palette color or a Custom Color.

Compare BUILD Interior Finishes

STONE FINISH

Aesthetic: Smooth texture, matte

Application: Two coats of Stone Plaster over a basecoat of Sand Plaster with optional Olive Oil Soap Sealer

Thickness : Coverage
Sand: 1 coat : 1/8" total: 50 ft²
Stone: 2 coats : 1/16" total: 150 ft²
Actual thickness and coverage may vary based on the condition of the brown coat.

Size: 32 lb / bag
Cost: $125 / bag

To Order: Using the Stone Finish Calculator, select PHL Binder substrate + enter your project square footage to calculate the materials needed for an interior BUILD project.

Product Page & Materials Calculator

SAND FINISH

Aesthetic: Coarse textured, matte

Application: One coat of Sand Plaster with optional Olive Oil Soap Sealer.

Size: 32 lb / bag
Cost: $100 / bag

Thickness : Coverage
Sand Plaster 1/8", 100 ft²
Actual thickness and coverage may vary based on the condition of the brown coat.

To Order: Using the Sand Finish Calculator, select PHL Binder substrate + enter your project square footage to calculate the materials needed for an interior BUILD project.

Product Page & Materials Calculator

FAQ

Yes — Earthaus offers consultation to help you adapt the BUILD Plaster System for a range of natural building techniques, climates, and project goals. Our plaster formulations are designed to be versatile and modifiable, and we’re happy to suggest adjustments based on your construction method, substrate, or design intent.

However, Earthaus is a materials manufacturer — not a licensed design, engineering, or contracting firm. Any guidance we provide is for general informational purposes and should not be interpreted as engineered system design. It is the responsibility of your architect, builder, or project engineer to evaluate any suggested modifications and ensure they meet the structural and code requirements for your specific location and project conditions.

Any diagrams, product data, or application notes provided by Earthaus are illustrative only. Final design decisions, detailing, and code compliance remain the responsibility of the project team. Earthaus warranties extend solely to the quality and performance of our materials when used as intended and properly applied.

We stand behind our plasters as high-performance, breathable systems for natural buildings—but successful implementation depends on collaboration with experienced professionals who understand your full project context.

Earthaus PHL is a pozzolanic hydraulic lime made with all U.S.-sourced materials, including pumice and hydrated lime. Unlike imported NHL (typically from Europe), PHL is more economical, more workable, and easier to apply — especially for natural substrates like adobe or straw. NHL can be stronger in some contexts, but it's often less breathable and less forgiving in dynamic wall systems.

Yes. For interior framed walls and ceilings finished with drywall, Sand and Stone Plasters can be applied to create a seamless, cohesive finish throughout your space.
Using the Sand or Stone Finish Calculator, select Drywall as your substrate + enter your project square footage to calculate the materials needed for interior finish plaster over interior framed walls.