INTERIOR DESIGN AND PRESERVATION STUDIO 1 | PROF. STEFANIA VARVARO | PROF. ROSSANA GABAGLIO

KNOWLEDGE PROJECT Historical studies… Geometrical Survey Materials and phenomena decay CONSERVATION PROJECT Cleaning Consolidation Protection

CONSERVATION PROJECT Contains any information necessary to slow the natural aging process of building materials and act directly on the causes of deterioration. It composes of drawings and technical cards. Drawings Indication of areas of intervention (it depends from material and its phenomena decay) Technical Cards All technical information for conservation works: which products, methods of application, etc. Each technical card describes only a specific operation.

FOR A CONSERVATION PROJECT… Foreword Knowledge of the building: - Its characteristics (geometrical, technical and construction); - Materials and pathologies of degradation; - The physical characteristics of the context (extrinsic causes of degradation) Aims On the causes: - Identification; direct intervention. On the Materials (only after recognize causes): - To remove of the decay products (CLEANING); - To increase and restore the consistency of the material (CONSOLIDATION); - To ensure the resistance of material to the atmospheric agents (PROTECTION)

This is the order of operation…only if material is very damage (polverization..) or very fragile (fresco..) is useful a consolidation treatments before the cleaning one.

CLEANING - Difficulties (theoretical-methodological approach, techniques) - Maximize the permanence of matter, elimination of only harmful deposits…and not “patina”, signs of time - Choice of the method (mechanical or chemical..or all these ones) - The action: less aggressive, intensifying gradually, and only if and where needed Treatments - Dry - Wet

Before and (on the right) after cleaning

MECHANICAL CLEANING WITH LITTLE HAND TOOLS to remove thin crusts, superficial deposit (dust, guano ecc.); low abrasive action tools: soft-bristle brushes (spazzole morbide), broomcorn- brushes (spazzole di saggina), scalpels, spatulas, scrapers (raschietti)…

WITH MECHANICAL TOOLS laser cleaning, cleaning with controlled sandblasting

WITH NEBULIZED, DEIONIZED WATER, WITH LOW PRESSURE uses the natural cleaning power of water CHEMICAL CLEANING specific chemical products to remove thick crusts (chemical solvent and clay or paper pulp, biocide..)

Cleaning with little hand tools

Manual spray and sponge

Swab with wooden stick

MECHANICAL CLEANING

Low pressure water spray cleaning It combines mechanical and washing action. It used for dirt not much adherent to the surface. Water have to be deionized (without salts and impurities) and atomized (water is like a frog of a fine drops).

You have to use low pressure (to not give mechanical action damage to material); spray not touch directly the surface but fall on it (for the same reasons). It’s better to use the least possible amount of water to not have erosion or impregnation of the material

MECHANICAL CLEANING

A thin jet of abrasive powder, consisting of granules of size, shape and hardness variables (balls of aluminum, glass, etc.) at low pressures. You can immediately see the effect of cleaning.

Cleaning through controlled sandblasting

MECHANICAL CLEANING

Cleaning by absorbing clays

CHEMICAL CLEANING

Absorbing clays with water give you a product with big absorbing power, like a foam. You put it on the surface and protect it with a waterproof layer (like silver foil). When you remove this layer -the shutter speed to be defined from time to time according to the tests- you have to clean the surface with water – deionize, atomized, etc. – to remove all traces of clays.

CHEMICAL CLEANING

Cleaning by absorbing clays

Cleaning with paper pulp and AB57 (chemical solvent)

CHEMICAL CLEANING

Cleaning through biocide

Spray application of suitable biocide; elimination of biological patina dry, by brushing; partial result of the cleaning. Clean with water atomized and deionized to remove all traces of biocide

CHEMICAL CLEANING

CONSOLIDATION It includes a series of treatments that aim to improve the cohesion and the adhesion between component of stone material . At the end of this operation the material is less subject to attacks by water and saline and acid solutions. The consolidating materials can be inorganic (barium hydroxide, calcium hydroxide…important for calcareous stones) and organic (resins) Superficial consolidation Structural consolidation (crack, fracture)

Microconsolidation

Consolidation through injection

Consolidation through compress

Re-filling

Aim to eliminate all possible routes of entry of water, closes all discontinuites of material

PROTECTION It ‘s an operation to prevent the attack surfaces by weathering; to limit the process of transformation that the material tends to be subject (it depends of the conditions of environment). It’s a layer which separates the material from the external environment, in order to oppose an appreciable resistance to water penetration. The product must have, however, also features breathable to allow the evaporation of the water contained in building materials. The products most used are alchyl-silane, poly-siloxane, silicon resins… Acrylic resins have little life and their effect is lost in about ten years. More suitable for the interior, particularly suitable for stone materials. The natural waxes (animal, vegetable and mineral) have a tendency to yellowing and to attract dirt; waterproof power decreases rapidly. The best known is beeswax, particularly suitable for wood Required features: light stability, no color change; colorless, no gloss and pearl effect; waterproofing and breathability Application methods: brush (on small parts); spray

SOME EXAMPLES

CONSERVATION TREATMENTS- references - C. Feiffer, La conservazione delle superfici intonacate. I metodi e le tecniche, Skira editore - C. Campanella. Capitolato speciale di appalto per opere di conservazione e restauro, Il Sole 24 Ore - P. Torsello, S. Musso, Il manuale del Restauro Architettonico, 2 volumi, UTET - Recupero e Conservazione - Arkos