Hydraulic Lime, Practical Advantages
Natural Hydraulic Lime (NHL) is generally associated with building conservation or as a green, eco-building material. That's hardly surprising, hydraulic lime goes back as far as the Greeks, Egyptians and Romans. It's use diminished in Britain in the 19th century as people adopted modern Ordinary Portland Cement (OPC).
However, we're learning more about these traditional materials now, than was ever known when they were popular. The inherent natural properties of hydraulic lime provide the same practical benefits of modern OPC but with none of the disadvantages. Naturally, NHL is perfectly suited for new build and can play an important role in the future of modern construction.
Hydraulic lime is fast setting, it can be used on-site just as efficiently as modern cement.
It sets by hydrolysis which renders it more practical in damp conditions.
More suitable for marine construction or masonry exposed to severe weather.
Shrinkage cracks in mortar and render can be virtually eliminated due to its hydraulic setting characteristics when correct moisture control techniques are employed.
It is breathable (vapour permeable), absorbing and evaporating moisture from surrounding masonry.
This also helps to protect the masonry, there is less risk of salt and frost damage.
It has a low modulus of elasticity.
This means it is extremely flexible and allows for movement and thermal expansion.
Available in NHL 2, NHL 3.5 and NHL 5 grades.
This allows design of mortars suitable for masonry of varied density and degrees of weather exposure.
It is supplied in powdered form, it is pretty much the same as mixing and working with a modern cement.
Mixed to the right consistency, hydraulic lime mortar, render or plaster are beautiful materials to work with.
It is softer than modern cement, a softer mortar will not wear away the surrounding masonry over time. Bricks and stones are also reclaimed more easily if dismantled.
Hydraulic lime mortars are indistinguishable from non-hydraulic limes.
They carry the same charming, traditional appearance.