Natural Hydraulic Lime (NHL) FAQs answer common questions about lime-based stucco systems, EcoMortar, breathability, curing time, strength grades, restoration use, and how NHL compares to cement and hydrated lime.
Natural Hydraulic Lime (NHL) is a 100% natural binder made from limestone that sets through a chemical reaction with water, providing breathability, flexibility, and strength without cement or additives. Mixed with sand, it forms a plaster or mortar suitable for walls, masonry, and lime-based stucco systems. Meoded offers Saint-Astier® NHL in different grades for sustainable, historic, and modern construction projects.
Natural Hydraulic Lime (NHL) is used for masonry, plastering, stucco, pointing, and restoration work. It is ideal for historic and modern construction because it offers strength, breathability, and flexibility. NHL is commonly used for exterior and interior walls, stone and brick masonry, lime stucco systems like EcoMortar, and moisture-sensitive structures.
NHL (Natural Hydraulic Lime) sets through a chemical reaction with water, allowing it to harden even in damp conditions. Hydrated lime (non-hydraulic lime) sets only by carbonation, reacting slowly with CO₂ from the air. NHL provides greater strength and durability, while hydrated lime is softer, more flexible, and better for plaster or limewash finishes.
Natural Hydraulic Lime (NHL) is a breathable, flexible binder made from limestone that sets slowly with water, allowing finishes to expand and contract without cracking. Cement sets rapidly and is rigid, making it more prone to cracks. NHL is ideal for masonry, restoration, and lime-based stucco systems like EcoMortar, offering durable, long-lasting finishes.
Yes, Natural Hydraulic Lime (NHL) is highly breathable. Its porous structure allows moisture vapor to pass through walls, helping regulate humidity and reduce condensation. This breathability protects masonry and finishes from trapped moisture, making NHL ideal for restoration projects, lime-based stucco systems like EcoMortar, and sustainable, long-lasting construction.
Natural Hydraulic Lime (NHL) is not fully waterproof, but it is water-resistant and highly durable. It can withstand rain and damp conditions without deteriorating, while remaining breathable to allow moisture vapor to escape.
These numbers indicate the strength and hydraulic set rate of Natural Hydraulic Lime. NHL 2 is the softest and slowest-setting, ideal for interior plasters and soft masonry. NHL 3.5 provides medium strength for general construction, including scratch, brown, and stucco coats. NHL 5 is the hardest and fastest-setting, suited for structural work and exposed exterior applications.
Yes, Natural Hydraulic Lime (NHL) is suitable for both interior and exterior use. Its breathability, flexibility, and water resistance make it ideal for interior plasters, masonry repair, lime-based stucco systems like EcoMortar, and exterior walls exposed to weather, ensuring durable, long-lasting finishes in all conditions.
Yes, premium Natural Hydraulic Limes, such as Saint-Astier NHL, are eco-friendly, contain zero VOCs and are made from 100% natural limestone with no synthetic additives. They are fully breathable, sustainable, and environmentally friendly, making them ideal for eco-conscious construction, masonry, plaster, and lime-based stucco systems.
Natural Hydraulic Lime (NHL) sets relatively quickly compared to non-hydraulic lime, but full curing takes longer. Initial set occurs within 12–48 hours depending on grade and conditions, while full carbonation and maximum strength can take several weeks. Proper curing ensures durable, breathable finishes for plasters, masonry, and lime-based stucco systems.
Yes, Natural Hydraulic Lime (NHL) is ideal for restoration and historic buildings. Its breathability, flexibility, and gentle curing process protect old masonry from cracking or trapped moisture. NHL allows walls to “breathe,” preserves structural integrity, and is compatible with traditional lime plasters, stone, brick masonry and limestone stucco systems like EcoMortar, making it perfect for heritage projects.
Natural Hydraulic Lime (NHL) based mortars are much less prone to cracking than cement-based products. Its flexibility and slow curing allow it to expand and contract with the substrate, accommodating movement without damage. When applied over a stable, properly prepared surface, NHL finishes maintain long-lasting, crack-resistant performance.
EcoMortar is a lime-based stucco system formulated with Saint-Astier Natural Hydraulic Lime (NHL) and sand. It provides a breathable, durable, and flexible finish for interior and exterior walls. EcoMortar combines the strength of hydraulic lime with traditional stucco techniques, offering long-lasting, sustainable, and aesthetically versatile finishes for modern and historic projects.
A lime-based stucco system, like EcoMortar, uses Natural Hydraulic Lime (NHL) instead of cement as the binder. It typically involves three coats—scratch, brown, and finish (stucco)—applied over a prepared substrate. Unlike rigid cement stucco, lime-based systems are breathable, flexible, and less prone to cracking, making them ideal for historic restoration and durable, sustainable construction.
Lime stucco, such as EcoMortar, is made with Natural Hydraulic Lime (NHL), making it breathable, flexible, and less prone to cracking. Cement stucco sets rigidly, dries quickly, and can trap moisture, leading to potential damage. Lime stucco is ideal for restoration, masonry, and long-lasting exterior or interior finishes.
These Natural Hydraulic Lime (NHL) FAQs are designed to help homeowners, builders, and restoration professionals select the proper lime grade, understand curing requirements, and choose the right lime-based stucco system for long-term performance.