Lime solution, its composition and characteristics

Gaining knowledge about the fundamentals of materials like lime solution can help you maintain and beautify the outside of your home. For centuries, builders have utilized lime solution, commonly referred to as lime wash or whitewash, as a multipurpose coating for their facades. Its basic yet efficient ingredients are water, hydrated lime, and occasionally other additives like fibers or pigments.

The main component, hydrated lime, is made from heated limestone that is combined with water to form a putty-like consistency. When this mixture is exposed to air, it goes through a carbonation process that eventually turns it back into limestone. Because of this special quality, lime solution is able to absorb and release moisture without becoming trapped inside the walls. For traditional or historic buildings made of traditional materials to remain healthy, this breathability is essential.

The natural antibacterial and antifungal qualities of lime solution are one of its most notable features; these qualities make it an excellent decorative option as well as a useful one for preventing the growth of mold and mildew on external surfaces. Lime’s high pH level makes it naturally resistant to biological growth by creating an unfavorable environment for microorganisms.

Lime solution has a unique matte finish that softens with time to give buildings a classic, weathered appearance. Lime solution blends in with the building’s surface, enhancing rather than masking its texture and character, in contrast to contemporary synthetic paints that can produce a coating that looks plastic-like. Architects and homeowners looking for a sustainable and eye-catching external finish love it for its ability to age gracefully and develop a natural patina.

What is lime

This material functions as a binder in the solution, or as the component of the component. As a result, gypsum in gypsum mixtures and cement in cement mortar are knitted.

Its manufacturing process remains unchanged over millennia. Limestone, the mineral of the same name, serves as her primary source of raw materials. The primary component of this sedimentary breed is calcium carbonate. In specialized furnaces, limestone is ground into a powder and burned, releasing carbon dioxide. The calcium oxide that remains in the form of lumps is known as negative lime.

The local term for it is Kipelka. This is because the water starts to attach itself to the stuck when it is added, and a significant amount of heat is released during this reaction. The resultant mass gets bigger and is primarily made up of bastard lime, also known as calcium hydroxide. In lime solution, it acts as an astringent.

Use in plaster solutions

Following the application of a lime solution to the wall, atmospheric carbon dioxide and gashenic lime—also known as a fur—interact. It is important to avoid overdrying the freshly plastered room because water is required for this reaction. The plastered layer solidifies and becomes a stone composed of calcium carbonate and sand after a few days.

The quality of the substance

In general, limestone is not a chemically pure breed. Furthermore, the amount of calcium oxide in the lime may differ if we consider that some of it is made from industrial waste.

The material’s quality is determined by its impurity content. Therefore, if clay was present in the initial raw materials, up to 20% of silicates, aluminums, and calcium ferrites will be present in the finished product after firing. This type of lime is known as hydraulic lime and is applied externally when water effects are felt on the plastered surface.

There are three primary categories for simple lime or air. Depending on how its impurities behave:

Because impurities function as inhibitors and alter the rate of extinguishing, this classification is significant. Therefore, normal is up to 25 minutes, skinny is more than 25 minutes, and fatty varieties are completely extinguished for 8 minutes. Complete eradication used to be possible even longer: the year that lime was mixed and cleaned could pass while plastering the surface beneath the fresco.

This is crucial in the modern era as well, since improper extinguishing causes the plaster layer to relax, adhere poorly to the wall, and give the impression of height.

The composition of the lime solution

This mixture consists of three main ingredients: sand, lime, and water. The most common way that lime is used is in dough form; owing to its high cost, fur powder is used less frequently. When boiling water is bred with water, a quantity of water that is ten times greater than what is required for extinguishing results in the lime dough. It turns out that the extinguishing process happens in lime milk. It’s crucial to thoroughly mix and eliminate lumps from the dough when making it. Garbage must be removed from the mixture if it is encountered.

Preparing the dough in warm weather and sturdy containers is preferable. You shouldn’t make a knead because the temperature can rise to 90 degrees after extinguishing. Shovels and mixers are options.

In 15 to 30 days, the dough will be ready at last. The term is dependent on both the air temperature and the quality of the dry material.

Stones should not be present in the small portion of sand that is appropriate for plastering. You have to strain it through a sieve in order to do this. This is particularly crucial for the plaster covering layer since unnecessary inclusions will cause the grout to become clogged or, in the words of plasterers, "draw."

The composition of the mixture

A table that represents the fundamental ingredients of one cubic meter of solution can be created:

Don’t pay too much attention to these figures. You should absolutely inspect its quality after kneading. It’s simple to do: Give the trowel a small amount of solution and observe how he responds to it. If it slides, you should add more lime because it was thin. If it adheres firmly, you can add more sand.

This kind of solution takes a few days to work, and it can be diluted with water if needed. Three applications of lime plaster are made: spray, soil, and covering. The composition of the first and last layers is more liquid, while the soil is thick. The maximum ratios of sand to dough were 1: 5 and 1: 6.

Lime solutions with the addition of other binders

Lime solutions have a few drawbacks, including slow hardening and poor strength. A combination of lime and other astringent was used to make up for these deficiencies. It is, first and foremost, cement and gypsum. As a result, the first addition will be a lime-gypsum mortar, and the second addition will be a lime-cement mortar. Within ten minutes of being added to the solution at the workplace, GIPS enables the composition to grasp more quickly and is applied to the wall.

The plaster layer is strengthened by the cement and can be knitted both centrally and locally. The brand of cement and the brand of the finished plaster determine the ratios of the cement-license solution. The cement, lime, and sand ratios for various solution brands are shown in the table:

In interior decoration, the use of tale mortar may seem excessive. To speed up gravity, the cement to lime ratio can be lowered to 1:1, 1:2, or even 1: 3.

Cement provides stiffness, while lime gives the solution flexibility. Plaster application was made more convenient by the addition of a plasticizer. Liquid soap is frequently used for this in daily life, but it weakens the plaster. You can buy an air-winning plasticizer in the retail network to prevent this. These liquids have the potential to decrease the amount of astringent needed, but more significantly, they aid in cement mixtures’ ability to retain their shape and avoid sinking.

Facade construction frequently uses lime solution, a traditional building material valued for its adaptability and sustainability. It is mostly made of calcium hydroxide, or slaked lime, combined with water to create a workable paste that adheres well to a variety of substrates, including plaster, stone, and brick.

Lime solution’s breathability is one of its main qualities; it lets moisture in the walls escape, preventing the growth of mold and moisture buildup. Because of this feature, it’s especially appropriate for older buildings or those located in humid climates, where controlling moisture levels is essential to preserving indoor air quality and structural integrity.

In addition, lime solution has the ability to mend itself over time. The process known as carbonation occurs when the lime ages and reabsorbs carbon dioxide from the air, turning it back into calcium carbonate. The material is strengthened and minor cracks are repaired by this natural process, extending the facade’s life and robustness.

The tensile strength and flexibility of lime solution can be increased for contemporary applications by adding fibers or pozzolans. These adjustments lessen the possibility of cracking and other damage over time by making sure it can tolerate outside stresses while still permitting the movement of the building materials.

An old-fashioned building material with many uses and environmental benefits is lime solution. It is mostly made of lime, water, and occasionally additional ingredients like sand or fibers. It provides a long-lasting, breathable finish for building facades. Among its many qualities is its exceptional permeability to moisture vapor, which aids in preventing moisture accumulation and the growth of mold inside walls. Because lime solution can be recycled or reused and has little effect on the environment, it also encourages sustainability. Comprehending its composition and advantages can improve the longevity and visual appeal of home facades, regardless of whether they are utilized in new construction or restoration.

Video on the topic

Lime mortar for masonry brick. Replacing Portland cement with available components.

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