What is a lime plaster?

It is a type of plaster composed of sand, water and lime, usually non-hydraulic hydrated lime. Lime rendering is perfectly suited for old buildings and is essential to use lime for restoring a building that was originally constructed with lime render. Lime renders are porous and flexible, allowing water to escape the building. Any fine cracks which develop will self heal, as opposite to cement, which cracks and lets water in. There are two types of lime plasters:

  • Natural hydraulic lime
  • Aerial lime  

Why use Parexlanko Lime plasters?

Illustration of hand trowel applying renovation repair mortar to historic heritage building wall

Respect of the old building

  • Low mechanical resistance
  • Flexibility and deformability
  • Water impermeability but porousity and vapour permeability
  • Reversibility of coatings

Qualities of implementation

  • Smoothness
  • Plasticity
  • Attaches to supports

Aesthetics and healthy building

  • Brightness
  • Respect for regional colours
  • Limitations of the appearance of mould, fungi, and micro-organisms
On what support can a lime plaster be applied?

The application of a lime plaster can be done on various supports, such as old masonry of rubble stones, bricks, natural stones including soft stones (chalk, tufa) mounted with low resistance mortar (DTU 26.1) , constructions of rammed earth, adobe, clinker, cob, cob, hemp... For each of our products, you will find all the admissible supports on the technical sheets.  

Posted on: 20/01/2022
Why make lime joints?

The use of a lime mortar is possible to repoint old masonry. It allows adhesion by molding to preserve the integrity of bricks or stones and dosages in accordance with traditional recipes on site.  

Posted on: 20/01/2022
Why use lime plaster?

Lime brings enormous benefits, which is why it is honoured during renovations of old buildings. Lime plasters and mortars are used for:

  • Their respect for old buildings

The microporosity of the lime allows the manufacture of a mortar permeable to water vapour. Lime thus makes it possible to avoid condensation, to reject humidity and thus allows the building to breathe. It also significantly improves interior comfort. 

Moreover, thanks to its bacterid properties, it limits the appearance of moulds, fungi and micro-organisms. 

Lime is also impermeable to runoff water and thus protects the building from external bad weather.

  • Their quality of implementation 

Lime makes it possible to produce creamy products that are easy to apply and work with and have good adhesion to substrates.

  • Their aesthetics 

Due to its luminosity and its characteristics adapted to the specificities of old buildings, lime gives an unequaled decorative cachet to a facade for a lasting restoration faithful to tradition.Finally, associated with other biosourced materials such as hemp, lime has insulating properties, both acoustic and thermal.  

Posted on: 20/01/2022

FAQ

What is heritage lime render and why is it used?

Heritage lime render is a breathable, flexible plaster composed of lime, sand and water. It allows moisture to escape, prevents condensation and damage in historic masonry, and self-heals any fine cracks that develop. All of this makes it ideal for restoring buildings originally built with lime renders.

What are the benefits of heritage lime renders?

These renders are breathable, flexible, ideally suited to absorb building movement, impermeable to rainfall yet vapour permeable, reversible, easy to work with, limit the appearance of mould and fungi, and compatible with regional colours and textures.

On which substrates can heritage lime renders be applied?

Lime renders adhere best to traditional substrates, such as rubble stone, brick, soft stone, rammed earth, cob and hemp. They are generally not suitable for modern impermeable or cement-based surfaces unless specific preparation steps are taken. For each of our lime renders specific substrate information and preparation instructions can be found on their Product Data Sheets.

What is the difference between lime render and cement render?

Lime render is softer, more flexible and breathable compared to cement render. While cement render can trap moisture and cause damage to historic masonry, lime render moves with the building and allows moisture to evaporate naturally.

What textures and finishes do Sika have available for lime renders?

Sika heritage lime renders come in various finishes such as float or sponge smoothed, medium scraped, brushed, spray textured and smooth spray textured. They’re available in a range of colours to suit different aesthetic requirements.