After years of research, global sourcing, and close collaboration with the world’s leading lime producers, we are proud to introduce a new chapter in our legacy:
Meoded proudly presents Saint-Astier® Natural Hydraulic Lime – the gold standard in sustainable restoration and durable construction.
Saint-Astier® is a family-owned business with a rich heritage spanning over four generations, dedicated to producing high-quality Natural Hydraulic Limes. They source their exceptional limestone from their own quarry, a vast 350-hectare underground deposit known as the ‘Cathedral of Limestone,’ ensuring unparalleled and consistent mineralogical quality even at depths of 200 meters. Renowned for its purity and absence of additives, Saint-Astier® Natural Hydraulic Lime (NHL) is a trusted choice for historic restoration mortar, stucco, and plaster, avoiding the use of harmful Portland cement. For over 150 years, Saint-Astier® NHL has been used worldwide to conserve, restore, and enhance various structures, from historical monuments and listed properties to vernacular and modern architecture.
Pure and natural hydraulic lime, gentle hydraulic, used when elasticity, low strength or high vapor exchange are desirable.
Recommended Applications – Smooth finishes & and mortars for weak stones.
Pure and natural hydraulic lime, moderately hydraulic, recommended when moderate strengths and better freeze-thaw resistance are required.
Recommended Applications – Base Coat, Scratch/Brown Coat and Stone Works.
Pure and natural hydraulic lime, eminently hydraulic, specified when strength and high freeze-thaw resistance are necessary.
Recommend Applications – Slabs, and Mortars for Hard Stones.
Trusted for over 160 years. Made in France. Loved worldwide.
Saint-Astier® NHL is the gold standard in lime binders—ideal for both historic restorations and sustainable new builds. Here’s what makes it stand out.
Unlike some tan or clay-heavy NHLs, Saint-Astier® contains lower iron and alumina levels—meaning no risky salt expansions, alkali-silica reactions, or hidden ingredients like gypsum or cement. You get a cleaner, more stable material that performs for the long haul.
Saint-Astier® keeps the “Free Lime” content just right—enough to self-heal cracks and improve freeze-thaw resistance, but not so much that it weakens the mortar or absorbs too much moisture. Some brands have 65–88% free lime, which makes mortars soft and spongy. Saint-Astier® hits the sweet spot.
Many producers have to manipulate their lime with fillers or re-burnt materials to meet standards. Saint-Astier® doesn’t. Their natural limestone deposit is so consistent and high-quality that no artificial tweaking is needed. What you see is what you get.
Need to adjust your mix? No problem. Saint-Astier® NHL retains 80% of its strength even after being reworked within 24 hours—meeting both European (EN 459) and American (ASTM C-141) standards. Most other NHLs can’t do this.
Saint-Astier® NHL 3.5 and NHL 5 can be mixed with sea water—yes, sea water!—without risk of damage. Perfect for coastal builds or islands where fresh water is limited. Over time, it gets even stronger.
Traditional Type-N or Type-O mortars with even a touch of Portland cement can damage old brick and stone. Saint-Astier® NHL is 100% Portland-free, making it ideal for sensitive restoration work.
What’s in the bag is what’s on the label. Saint-Astier® is true Natural Hydraulic Lime—no blends, no cement, no additives. Just add sand and water, and you’ve got a top-quality mortar.
Architects, conservators, and builders worldwide trust Saint-Astier® for its reliability, consistency, and unmatched performance. It’s not just another lime—it’s the benchmark others are measured against.
Saint-Astier® NHL The natural choice for those who demand the best.
This is the most widely used type of lime. It comes either in a powdered form, such as Type N, NA, S, or SA, or as a paste known as Lime Putty. While Hydrated Lime boasts excellent physical and aesthetic properties, it has significant limitations in construction. It sets only through carbonation (the re-absorption of CO2), which restricts its use to thin layers. It is impractical for use in scratch or brown coats in plaster but can be highly effective as a finish coat, often requiring blending.
Hydraulic Lime is a vastly superior material to hydrated lime for most construction applications, especially where strength, durability, and performance are required. While it is chemically related to hydrated lime, its key difference—and major advantage—is that it sets through a combination of hydration (with water) and carbonation (with CO₂). This dual-setting process gives hydraulic lime significantly better performance in a wide range of conditions.
Unlike hydrated lime, which sets slowly and only in contact with air, hydraulic lime can set in damp, cold, or even underwater environments—making it ideal for structural applications, thicker plaster layers (including scratch and brown coats), exterior use, and areas with high humidity.
There are three main grades of Natural Hydraulic Lime (NHL):
Hydraulic lime maintains breathability, flexibility, and compatibility with traditional materials—qualities that are essential in the restoration of historic buildings and beneficial in modern eco-conscious construction. It provides strength without sacrificing vapor permeability, reducing the risk of trapped moisture and associated damage.
High-quality hydraulic limes like St. Astier NHL derive their hydraulic properties naturally from the specific composition of the limestone from which they are produced—no additives or cement are required. This results in a more stable, reliable, and long-lasting material than so-called “hydraulic” blends made by adding pozzolans or cement to hydrated lime, which can compromise performance and building longevity.
In terms of application, hydraulic lime can be used by the same tradespeople who apply stucco or plaster. While some care must be taken with mixing and curing, the learning curve is small, and the benefits are significant. The final result is a more durable, breathable, and aesthetically pleasing finish that will stand the test of time.
Quick Comparison:
NHL 2 vs NHL 3.5 vs NHL 5
Compressive Strength (28 days)
~2 MPa
Slow
Very High
High
Moderate
Use in Marine/Coastal Areas
Not Recommended
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