Historical & Geological Context
Natural Hydraulic Lime (NHL 3.5) is burned from argillaceous limestone containing natural silicates. It achieves an initial hydraulic set in contact with water, followed by prolonged atmospheric carbonation. With moderate compressive strength and high elasticity, it flexes with historic building movements without cracking delicate soft stone or historic bricks.
Petrographic & Geological Characteristics
Argillaceous limestone calcined and slaked to preserve natural dicalcium silicates (C2S).
Lime Mortar & Breathability Compatibility
Dual setting: initial hydraulic set underwater followed by long-term carbonation. Ideal for exterior ashlar.
Provenance & Historical Sourcing
Unique silicious limestone basin of Saint-Astier in the Périgord.
Condition Report & Patina
Certified EN 459-1 pure NHL 3.5; zero fly ash, slag, or portland clinker.
Chaux Hydraulique Naturelle Pure (NHL 3.5)
Dordogne, France (FR)
Non-commercial reference. Not sold or brokered by Le Cercle du Roi.
This material dossier is compiled from public geological surveys, heritage conservation research (BRGM, CTMNC, Historic England, Monumentenwacht), and historical treatises. Inclusion does not constitute a sales offer by Le Cercle du Roi.