Product Overview
EcoMortar® Base is a dry, ready-to-use lime mortar formulated with Saint-Astier® Natural Hydraulic Lime. Specifically designed to serve as the scratch and brown coat in a lime render or stucco system, it provides excellent adhesion, flexibility, and breathability — all without cement or synthetic additives. As the foundation layer in traditional or modern lime plaster systems, EcoMortar® Base is used to level and build up the wall surface in preparation for the final finish coat. Its natural composition makes it ideal for both new construction and restoration work, ensuring compatibility with a wide range of masonry types. Durable, eco-conscious, and easy to apply, EcoMortar® Base is the trusted starting point for long-lasting, breathable stucco systems. Pair EcoMortar® Base with EcoMortar® F3.5 Finish to complete your stucco system, a perfect match for long-lasting, natural, and breathable exterior finishes.
Key Benefits
● Vapour Permeable: Facilitates moisture movement, reducing the risk of trapped moisture and associated damage.
● Cement-Free Composition: Composed solely of natural hydraulic lime, ensuring compatibility with historic masonry and sustainable building practices.
● Easy to Mix and Apply: Designed for straightforward application, enhancing work efficiency.
● Suitable for Traditional Masonry: Ideal for use on stone, brick, and other traditional building materials.
● Environmentally Friendly: Produced with lower energy than cementitious mixes and contributes to CO₂ re-absorption during curing.
● Contains Zero VOC
Recommended Applications
● Base Coat for External Lime Renders: Provides a solid foundation for finishing coats in lime render systems.
● Restoration Projects: Perfect for use in the conservation of historic buildings requiring breathable and compatible materials.
● Eco-Friendly Construction: Ideal as a scratch and brown coat in new builds focused on sustainable, natural building methods.
Packaging and Storage
● Available Sizes: 77 lb bags
● Shelf Life: 12 months from the production date when stored in dry conditions and in original packaging.
● Storage: Keep in a dry, cool place to maintain product integrity.
Composition
● Binder: Saint-Astier® Natural Hydraulic Lime
● Aggregates: Well-graded fine sands
● Additives: Natural additives to enhance workability and curing
Application Guidelines
MIXING
Mix for 4 to 5 minutes with a whisk mixer (450 to 500 rpm). High-speed mixers (more than 500 rpm) are not recommended as they can over-mix the product and modify its performance. Manual mixing is not recommended.
WATER ADDITION
EcoMortar® Base requires approximately 1.5 – 2.0 gallons (192-256 fl. oz.) of water per 35kg (77lb) bag, depending on desired workability and application type. Add water gradually until desired consistency is achieved.
CONSUMPTION / COVERAGE
Scratch Coat: Approximately 35-45 sq. ft. per coat at 8-10mm (5/16″-3/8″) thickness.
Approx. 1.925 lbs per sq. ft. at 3/8″ (9.5mm) thickness, depending on surface porosity and texture.
Brown Coat: Approximately 50-60 sq. ft. per coat at 8-10mm (5/16″-3/8″) thickness.
Approx. 1.4 lbs per sq. ft. at 3/8″ (9.5mm) thickness, depending on surface porosity and texture.
For uneven or exposed surfaces, multiple coats may be necessary, allowing each layer to firm up before the next.
(MAX. thickness of 10mm per coat)
APPLICATION NOTES
Apply on dampened, clean, and sound substrates. Do not apply to frozen surfaces or in direct sun on hot days. Ensure proper mechanical keying for optimal adhesion (e.g., open texture or scoring). Do not apply in layers thicker than 3/8″ per coat. For thicker builds, apply in multiple coats, allowing each layer to partially set before the next. Wait a minimum of 6 days between scratch and brown coat. Spray the scratch coat with water daily for the first 3 days, then moist it again 20 minutes prior to the brown coat application. Let the brown coat dry for 5 to 7 days, before application of the EcoMortar® Finish. Wet the brown coat for the first 2 days, then moist it once more 20 minutes before applying the EcoMortar® Finish coat.
WORKING TEMPERATURE
Apply between 8°C and 30°C (46°F to 86°F). Lightly dampen substrates before application. Avoid rapid drying from heat or wind; cure gently with water misting if needed. Protect fresh mortar from frost and drying winds for at least 10 days after application. Seal opened bags immediately after use. On hot or windy days, lightly mist the surface every few hours for the first couple of days to prevent premature drying.
TOOLS & CLEAN-UP
Apply using a steel trowel or plastering float. Clean tools with water before material hardens.
Technical Specifications
| Property |
Value |
| Dry Bulk Density |
1400 kg/m³ |
| Compressive Strength |
7 days: 1.2 N/mm²
28 days: 1.9 N/mm²
90 days: 3.6 N/mm² |
| Elasticity Modulus |
5000 MPa |
| Vapour Permeability |
0.85 g/m²·h·mmHg |
| Capillarity |
Type C and F |
| Maximum Grain Size |
EF: 0.8 mm
TF: 1.3 mm
F: 1.8 mm
M: 2.5 mm |
Note: “EF” refers to the Extra Fine granulometry, “TF” to the Thin Fine, “F” to Fine, and “M” to Medium.
