Applications and uses of lime mortar. Where is lime mortar used?

Lime is used in different fields, including agriculture, gardening, industry and construction. For building mortars, quicklime is usually not used directly; instead, slaked lime or lime putty is used. Lime mortars are valued for plasticity, workability, vapour permeability and their ability to work with soft porous materials.

Features of simple lime mortar

Lime mortars can be simple or complex. In a simple mortar, only one substance acts as the binder component (lime), while in a complex mortar there are several binders (cement, gypsum, lime).

Simple lime mortar is a mixture of slaked lime or lime putty, water and sand. When preparing it, it is important to use already slaked lime, follow safety rules and choose proportions for the specific task. The strength and reliability of the finished work depend on the composition, sand quality, amount of water and curing conditions.

Features of complex lime mortar

As mentioned earlier, complex lime mortar includes several binders or additives. Lime-sand, lime-cement and lime-gypsum mortars are commonly distinguished. Additives are selected according to working conditions: cement increases strength and moisture resistance, gypsum speeds up setting, and lime improves plasticity and ease of application.

It should be noted that lime mortars can be lean, normal or fat. A lean mortar contains too little binder, so it has poorer adhesion, lower plasticity and may crumble. A mortar that is too fat contains excess binder, shrinks more and may crack while drying. In practice, the goal is a normal mix that is easy to apply and does not give excessive shrinkage.

Use of lime-gypsum mortar

Lime-gypsum mortar includes lime, water, gypsum and sand. Gypsum is added to reduce setting time, because simple air-lime mortars harden slowly. This type of mix is used mainly for interior plastering in dry rooms. For wet areas and exposed exterior surfaces, gypsum additives should be used with caution or avoided, because gypsum is sensitive to long-term moisture.

Use of lime-cement mortar

One of the most popular fillers for lime mortar is cement. It is added to the mortar for specific construction purposes, for example, finishing and facade work. The popularity of lime-cement mortar is explained by its relatively low price, strength and plasticity, as well as good adhesion of the mortar to the surface. To prepare such a mortar, only high-quality slaked lime is used. Lime-cement mortar is actively used for finishing work in rooms with high humidity. It can easily be used to plaster walls made of brick, wood and concrete.

Use of lime-sand mortars

This type of mortar involves mixing lime, water and sand. The sand should be sifted and cleaned of excess impurities, and the proportions are selected according to the purpose of the mortar and strength requirements. Ratios of about 1:2 or 1:3 for lime and sand are often used, but there is no universal proportion for all work. To increase strength and moisture resistance, cement may be added to the mixture, producing a lime-cement or cement-lime mortar.

The applications of lime mortars are mainly related to construction and restoration. They are used for masonry, plastering, repair of old brick and stonework, and in places where plasticity and vapour permeability are important. When choosing a mix, it is necessary to consider humidity, temperature, substrate material and strength requirements.