Wall plaster with lime mortar: lime damping, mixture proportions, application

Lime mortar is a traditional option for plastering walls because it provides a natural finish and durability. Because of its special qualities that give walls flexibility and breathability, lime mortar has been used for centuries. It’s an adaptable material that keeps its integrity under a variety of circumstances.

Working with lime mortar requires an understanding of lime damping. The process of letting lime absorb moisture and mature before using it is known as "lime damping." In order to guarantee that the mortar reaches the proper consistency and strength, this step is essential. Over time, the performance of the plaster can be greatly impacted by proper damping.

Proper mixing of lime mortar is an additional crucial element for an effective application. Plaster adheres and cures well when the lime, sand, and water mixture proportions are correct. Correctly calculating these ratios contributes to a durable, smooth finish that can withstand a range of environmental factors.

Lime plaster application requires meticulous planning and execution. Lime mortar application may be different from other plaster types, but done correctly, it can improve the durability and appearance of your walls. Whether you’re plastering a new building or renovating an existing one, knowing these tricks will make your work look better and work more efficiently.

A classic tool for wall plastering, lime mortar is renowned for its flexibility and longevity. This article discusses the ideal methods for applying lime mortar, how to mix it properly, and how it functions as a dampening agent. Having a thorough understanding of these elements will help guarantee a durable finish that improves the look and functionality of your walls.

What is lime plaster

Plaster’s plasticity and resistance to cracking can be greatly increased by adding lime to solutions. Working with her becomes much simpler; it doesn’t dry out as quickly, adheres to the tree with ease, and has a smoother, flawless surface. It offers great defense against fungus and mold as well. Unquestionably, another benefit is that lime is environmentally friendly; unlike artificial additives, it poses no threat to the environment.

Lime is a common plasticizer used in construction. It should be remembered, though, that plastering facades is only permitted in regions with a dry climate. It is also not advised to use these solutions in rooms with high humidity levels (above 60%).

When it comes to repairs, lime plaster is much easier to remove from the walls than, say, regular cement because it is warmer and more vapor-permeable, or "breathing." However, too much lime may cause the surface strength to deteriorate. Because of this, it ought to be added sparingly, carefully following the ratios.

Lime plaster, as we can see, has numerous benefits. One of the drawbacks is that they are not as strong as cement compositions. Additionally, using it to lay tiles or in damp rooms is not advised.

However, it is not necessary for such a solution to be extremely powerful. Plastering is, after all, intended to level the surface and seal small cracks. For laying, a stronger solution is needed. But in this instance, SNiP says it’s acceptable to add a tiny bit of clay or lime dough to it to make it more flexible.

You should use extreme caution when extinguishing the lime because hot mixture splashes can cause burns. Even the tiniest lime dust particles have the potential to cause harm, as they can accumulate on the mucous membrane. As a result, you should wear gloves, a respirator, and protective clothing when working.

Preparation of calcareous milk (extinguishing)

Because calcium oxide, or negative lime, releases a lot of heat and water vapor when it interacts with water, it is not appropriate for use in pantry or plastering applications. Here, CA (OH) 2 is the alkali that is formed. This is where cooking plaster is required. Fur (gathered lime) can be prepared by hand or purchased as a powder.

Extinguishing is a fairly easy process. You must make lime milk first. Put in a bath or bucket:

• clean cold water;
• lump lime in a ratio of 1:1 from the mass of water.

Lime should be added gradually, in tiny pieces, while the mixture is continuously stirred. If not, the material will not react entirely because the top layer, having started a reaction, forms a hydroxide on the surface, preventing water from reaching the lower portion of the container.

This kind of plaster is typically used to finish utility rooms and is thought to be a less expensive alternative to cement mixtures. Similar proportions apply in this instance:

• for preparing a primer solution, the ratio of lime and sand is 1:2;
• when spraying it on the walls, it is 1:2;
• for use as a main finishing coating 1:5.

Lime-sand plaster is made by mixing the ingredients dry and then adding water. Sifted river sand should be used instead of unclean sand for mixing.

Since this mixture takes time to harden, you can cover it with polyethylene and use it the following day. It won’t lose its characteristics.

Lime-cement

Because of its high durability, this plaster is frequently used for interior and facade construction. Depending on the goal, the mixture’s component ratios change:

• for spraying 1:0.4:4 (cement, lime dough, sand);
• when used as a primer: 1:1:4;
• for obtaining finishing coatings: 1:1.5:1.5.

Additionally, pre-made dry mixtures like the Weber Vetonit 414 brand are available for purchase. It works well on any surface, both indoors and outdoors. Because the plaster is reinforced with microfiber, it can be used as a base or leveling layer and hardens without shrinking. Vetonit consumes 1.4 kg/m2 at a 1 mm thickness.

Lime-gypsum

You can accelerate the hardening process and obtain a more level and resilient surface by mixing gypsum with sand-lime solution. This kind of solution works great even on wooden and stone surfaces.

The following are the dilution proportions:

• when sprayed (lime paste, sand, gypsum): 1:0.5:2;
• for use as a base coat: 1:1.5:2;
• as a primer: 1:1:2.

Working with such compositions is more challenging because the solution solidifies so quickly. It needs to be prepared in small amounts as a result.

Lime-clay

Very rarely, this plaster is used to finish fireplaces, stoves, and huts. It’s ready in this manner:

• proportions for primer (lime paste, clay, sand) 2:1.5:2;
• for mixing as a coating 2:1:3.5;
• for spraying 2:1:3.

A medium-fat clay should be used for mixing. Its quantity in the mixture needs to be increased if it is lean and the solution does not adhere to the trowel. Conversely, if the clay is overly viscous, the proportion of sand needs to be raised.

Plastering with lime mortar

Preparing the walls

Remove all of the outdated finishing if you are renovating rather than starting from scratch with blank walls in a new building. Using a metal brush or scraper, old wallpaper is removed after being moistened with water. If the old whitewash needs to be completely removed, the surface can be wetted with liquid paste. Using a spatula, it is simple to remove the glue and whitewash once it has dried.

With a grinder or knife, large cracks are widened. After that, they are primed, dusty, and sealed with a robust cement mortar. Serpyanka tape has been used to secure their locations.

Using an axe or hammer drill, create notches about 10 cm wide to ensure plaster is firmly fastened to concrete or brick walls. Wooden strips called shingles are used to cover wooden walls. It is secured with nails, which only need to be bent slightly rather than hammered all the way in. A metal mesh that is pressed onto the roof can be used to replace the shingles.

The first layer cannot be applied without priming the walls. The primer will strengthen the plaster’s adherence by adhering to any leftover dust.

Guide beacons are used when exact evenness is required. After using a tiny bit of putty to secure them to the wall, they are leveled. The rule that will be used to level the mixture during plastering should be spaced 20 cm shorter between beacon profiles.

Applying plaster

Let’s talk about the technology involved in plastering walls by hand instead of utilizing a machine. Three layers are required when using lime plaster to achieve a high-quality surface:

1. Scrap is used for better adhesion of the subsequent layer to the surface. In this case, the solution is prepared more liquid, with a creamy consistency. It is simply thrown onto the walls in a thin layer and is not leveled.
2. Main primer layer. Its thickness is 1-3 cm. It is a thicker solution. It is applied with a trowel or a float between the beacon profiles. The rule is used to level the plaster and remove excess.
3. Finishing layer (covering). Used to smooth the surface and remove minor defects. The consistency of the solution is similar to a splash. The layer thickness is several millimeters. After application, rub with a float.

Counseling! Applying an excessively thick primer layer is not advised because lime mortar sets more slowly and can "float." Apply it once more in a second or third layer, allowing each to dry for approximately a day. Only after the plaster has fully dried can such a surface be rubbed.

In the event that plaster needs to be repaired after a while, the steps involved in doing so can be repeated: clean the finish’s chips and cracks; prime the wall; apply the mixture in multiple layers; and rub once it has dried.

Plastering walls with lime mortar is a time-tested and efficient method of creating surfaces that are both breathable and long-lasting. Lime damping’s special properties aid in controlling moisture, extending the life of your plasterwork. You can make a plaster that can withstand different kinds of weather and still provide a smooth surface by combining lime with the appropriate amounts of sand and water.

Lime plaster application calls for meticulous attention to detail. Good adherence and a long-lasting finish are ensured by properly priming the surface and layering the plaster. In order to prevent common problems like uneven surfaces or cracking, it is imperative to adhere to recommended techniques and curing times.

All things considered, lime mortar is a tried-and-true option for wall plastering. It is a useful alternative for both conventional and modern building due to its advantages in moisture management and flexibility. You can get a long-lasting, high-quality finish with careful mixing and application.

Video on the topic

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