Lime is ideal for Mortars, plasters, and paints, especially in historic preservation and restoration -

  • Lime mortars sacrificially protect stone and brick
  • Lime mortars, paints, and plaster allow your walls to “breath”
  • Lime mortars can and have lasted hundred of years.
  • Lime mortar creates water tight walls
  • Lime mortars create stronger, more structurally sound walls
  • Lime paints, have special light refracting and reflecting qualities that make them extraordinarily beautiful.

Used in mortars, plasters, stuccos, and paints for centuries, if not millennia, lime is one of the most versatile and long lasting building materials ever used. Lime has many attributes that make it specially suited for use in masonry restoration.

Unlike today’s framed structures with masonry veneers, traditional masonry structures were just that– solid masonry. The thickness of the walls kept moisture out of the living space and provided strength. Inevitably, the thickness of the walls also guaranteed they would constantly contain. This all worked very well with lime mortars, plasters, and paints (lime wash) because lime is able to absorb large amounts of water, and due to its porosity, very easily release the moisture back into the atmosphere. Substitution of modern materials for historic lime based materials can lock moisture into walls causing a myriad of problems including failure of masonry units, interior water damage and structural failure of interior wythes of the wall.

In addition to vapor permeability, lime has other attributes that make it desirable to use in historic restoration, preservation, and masonry construction. Lime is flexible and soft, i.e. it has a high flexural strength and low compression strength. Thus, as buildings settle, and move through thermal expansion and contraction, the lime components are able to absorb this movement. In the case of masonry walls, absorption of this movement in the mortar joints, protects the bricks and stones from damage.

The last major advantage of lime is that when used in mortars, it has a much higher bond strength than unmodified non-lime mortars. Lime has a much smaller particle size than other common mortar binders (e.g. 1/500th the particle size of Portland cement) consequently lime more effectively fills and bonds the pours of your brick or stone. Additionally, because lime creates creamier mortars, there is no need to introduce air entraining agents to the mix. Air entrainment creates bubbles and lessens the surface area contact between the mortar and the brick and stone. Because of these properties and the high flexural strength, only lime mortars have always been permissible by code in seismic zones 3 and 4.

The use of traditional lime materials does present some challenges. Lime cures differently and by different mechanisms than modern materials. The curing process can also be more affected by adverse weather conditions. In fact, masons and craftspeople well versed in modern materials often have problems installing lime materials. Many have given up on the products or try to talk clients out of using them due to inexperience and misunderstanding. Centennial Preservation uses only lime mortars and is well versed in the application of all lime materials. Consequently, our craftsman truly understand these materials and how to properly use and cure them in any weather condition so that your restoration or preservation project is beautiful and functioning long into the future.

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