How to do the restoration of facade plaster

In the planning of our cities, the theme of urban redevelopment occupies a central place. As a result, the design interventions are more aimed at reconnecting open space and built volume, a concept that we have already covered in a previous focus dedicated

We continue to talk about interventions on the existing one, specifically the restoration of the facade plaster of buildings in historic centers. The following discussion should be considered as a brief guide with general indications to be adopted. Only an in-depth study of the individual case and the professional expertise of the designer in charge can lead to the development of the most suitable solution

With the restoration of the façade, it is possible to recover the image of the building, often overlooked or dissipated in favor of layered and superimposed solutions over time, linked to tastes and needs not supported by a line of coherence and rigor that the urban text of a historic center requires.

Before proceeding with the demolition of existing plaster, it would be good practice to ensure that there are no paints and plasters worth safeguarding. Once the absence of this possibility has been verified, the plastered support can be demolished.

Once the old plaster has been demolished, it is necessary to thoroughly clean the entire wall surface, removing any possible trace of grease, every moving particle and all the dust, brushing thoroughly.

Before applying the new plaster, it is necessary to wet the old wall. This operation is essential for the success of the surgery and the resistance of the new plaster over time.

It is necessary to wet the masonry thoroughly until it is saturated; in this way all the salts contained in it can melt. It is suggested to do this operation before summer, in order to take advantage of the summer period to ensure that the moisture in the wall can completely evaporate, and then proceed with the installation of the new plaster

The stages of making the plaster are the traditional ones, namely:
1. first layer: stingray;
2. second layer: curl or curl;
3. third and final layer: plaster.

But what is the most suitable plaster to use in restorations? Certainly traditional materials such as aerial lime, hydraulic lime, gypsum and lime putty for plastering

To proceed with the drafting of the first layer of plaster, posts and guides are made, which serve to give the right direction of installation in order to have a perfectly coplanar plaster. In order not to run the risk that, once the plaster has dried, you can see the position of the guides, it is suggested to make the guides with the same type of mortar that will be used later and to spread the first layer of the plaster before the guides are dry

To make the curl there are two clearly distinct methods:
— stretch the curl before the rinsaffo is dry;
— spread the curl when the rinsaffo is

The choice of one or the other must result from a careful comparison between the designer and the workers.

Once the plaster has been applied, it is advisable to drizzle the plastered surface to delay drying, in order to limit possible chipping and at the same time make the plaster more resistant.

The plaster, the last layer of the plaster, has a very thin thickness. It can be performed with different tools and methods, on the basis of which the plastered surface takes on different aesthetic effects

Among the most common are:
— the trowel plaster; the tool used is the trowel, it appears smooth and homogeneous, it can be without lines or with light lines;
— laminated plaster is made with trowels or metal blades and is perfectly smooth;
— the scratched plaster, made of wooden boards or rough glass sheets, is rough to the touch and sight, it can be in horizontal or vertical bands;
— the combed plaster, made with wooden or steel combs, is striated with very marked horizontal or vertical grooves;
— patched plaster, made with tools equipped with tips that evenly scratch the surface, has a visual effect similar to speckled;
— brushed plaster is made by applying inert, terracotta chips or ground natural stone to the finishing layer.
— sprayed plaster, made by spraying the last layer with trowels or mechanical tools, is uniformly grainy to the eye

The restoration can be completed with a lime-based paint. Lime paint has notoriously little resistance to weathering and contact. To overcome these drawbacks, today's production offers highly performing solutions. These are lime-based paints enriched with additives that allow defects to be limited, while maintaining not only the aesthetic prerogatives, but also the technological ones, such as the breathability of the dye, which allows old walls to breathe while limiting

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