Lime Plaster

Lime plaster is an integral part of the chemical substances used in modern applications. It is also called hot lime, fat lime, lime putty, etc. It is made up of lime, water, and sand. When talking about lime plaster, it is for the non-hydraulic version. It is different from the traditional cement plaster.

Let us know all about the chemical composition of this lime plaster, its key benefits, and the possible areas of concern. The common properties of lime plaster include quick setting, durability, and cement-like properties. We’ll cover related topics like lime plastering and the main differences between lime plaster and cement plaster. 

What is lime plaster?

It is an innovative form of plaster that is made up of calcium hydroxide, sand, and water. It is one of the best plasters available and offers multiple benefits like condensation, breathability, flexibility, and ease of working. The popularity of lime plaster is high because it protects the building and offers support to the structural integrity of the building.

Lime plastering is prepared by heating the limestone or calcium carbonate at a temperature above 850 degrees Celsius. The quick lime or calcium oxide thus produced is converted to the slaked lime or calcium hydroxide by adding water. Hence, lime plaster is sold as a white powder or wet putty. Water is added to this powder before using it. Further, when it reacts with atmospheric carbon dioxide, calcium hydroxide turns back to calcium carbonate.

Benefits of lime plaster:

Some of the advantages of lime plaster are:

• It has a high pH value and is perfect for eliminating the growth of fungi and bacteria. Hence, there is no possibility of mould growth in the lime plaster.
• It is least affected by water. Hence, it is beneficial over gypsum plaster, earthen plaster, or drywall plaster.
• It is absorbent plaster that allows quick diffusion and moisture evaporation.
• It is one of the most durable forms of plaster compared to other counterparts like clay plaster, gypsum, etc. Hence, lime plaster is widely used as the lime render on the exterior of buildings.
• There is no requirement for the expansion joints in lime plaster. It is less brittle than cement plaster and is used widely in modern buildings.

Disadvantages of lime plaster:

Some points of concern in the lime plaster are:

• The non-hydraulic form of lime plaster sets slowly.
• It is highly acidic white when in wet form and hence needs utmost care for the elimination of patches.
• The lime plaster may cause chemical burns as it can have a pH as high as 12. Hence, the plasterers use mild acids or vinegar or lemon juice to neutralise chemical burns.
• It requires sufficient moisture to set and needs to be protected from drying for a couple of days.
• There is an increasing shortage of plasterers capable of doing lime plaster activities.

Difference between lime plaster and cement plaster:

The key differences between lime plaster and cement plaster include:

 Conclusion

Hence, it is easy to understand all about lime plaster. It is made up of sand, lime, and water and is widely used to construct different buildings. It has multiple advantages over traditional cement plaster and is gaining popularity globally.

It can be denoted by calcium hydroxide or Ca(OH)2. It is made when the plaster comes into contact with the air’s carbon dioxide and then gets transformed into calcium carbonate. The lime plaster is prepared using calcium carbonate and heating limestone at a temperature over 350 degrees. Lime plaster is used in multiple applications and chemical reactions based on the benefits.