Non-hydraulic lime is also known as either hydrated lime or putty lime. Lime Putties set and harden through drying out and absorbing carbon dioxide from the air. They typically have a very slow set: CO2 is only absorbed when certain conditions are met. Putties are the softest, most breathable limes available.
Lime putty is made by adding an excess of water to quicklime - a process known as "slaking". Quick lime is super-heated limestone which is quenched in water quickly. The result is a chemical reaction between the carbonated stone and the water which results in the putty formation. When this cools down you are left with pure lime putty which should resemble clotted cream.
Lime putty is used as a lime mortar, lime plaster and repair mix when mixed with aggregates like sands and stone dusts. Lime putty can be used for flexible background plastering, soft brickwork and stone repairs. For more details on this please contact us and we can discuss the specifics of your project and the most suitable Limes required.
The main advantage to be gained from using lime putties in a lime mortar or lime render is their ability to allow old walls to breathe - very important for moisture control / damp prevention. Putty is pretty much the opposite to cement which is far too strong, impervious and tends to hold moisture captive within walls that have been built in solid form without a cavity.
To view our selection of Lime Putties and washes with more information on their application please feel free to click here