GDW Scientific Report

CASTEL GRUMELLO

Conservation studio Group 8

A.Y. 2014-2015

CASTEL GRUMELLO Conservation+Studio A.Y. 2014-2015

Index..................................................................................................................................................................................3 Introduction ...................................................................................................................................................................5

Castle description..............................................................................................................................................6

Actual state..........................................................................................................................................................7

Recent intervention...........................................................................................................................................7

Area of intervention..........................................................................................................................................7

Target....................................................................................................................................................................8 Methods...............................................................................................................................................................8 Metric survey ................................................................................................................................................................10

The survey..........................................................................................................................................................12

Horizontal survey............................................................................................................................................13

Materic plan, trilateration..............................................................................................................................14

Vertical survey..................................................................................................................................................16

Photogrammetric survey................................................................................................................................18

Problems encountered during survey..........................................................................................................19

Comments and considerations.......................................................................................................................19

Materic survey ..............................................................................................................................................................20

The survey.........................................................................................................................................................20

Petographic analysis........................................................................................................................................20

Sedimentary rocks...............................................................................................................................20

Metamorphic rocks.............................................................................................................................21

List of rocks classified on site........................................................................................................................22

Other material classified on site...................................................................................................................23

Materic plan......................................................................................................................................................24

Materic elevations............................................................................................................................................26

Degradation survey ....................................................................................................................................................28

The survey..........................................................................................................................................................28

Recognition of the degradation according to ICOMOS..........................................................................28

Survey process..................................................................................................................................................30

Metric survey....................................................................................................................................................30

Materic survey..................................................................................................................................................30

Degradation survey.........................................................................................................................................31

Degradation plan.............................................................................................................................................32

Degradation elevations...................................................................................................................................34

Comments and considerations.......................................................................................................................36

Historic investigation.........................................................................................................................36 Bibliography .................................................................................................................................................................37

Plitecnico di Milano Conservation+Studio A.Y. 2014-2015

Group 8

Prof. Elisabetta Rosina Prof. Alessia Silvetti Eng. Silvia Erba

Secchi Gabriele 762698 - Sterle Enrico 762168 -

Ksenia Alontseva Ksenia 836347 Suardi Andrea 840742 - Ksenia Voronova 836308

Castel Grumello (So)

Introduction: Sondrio’s province extend from Adda Valley till Valtellina including all the Valchiavenna.The province borders Switzerland (precisely, the Canton of Grisons) to the north and west, the provinces of Como and Lecco to the west, the provinces of Bergamo and Brescia to the south and Trentino-Alto Adige/Südtirol region to the east.

The district is mainly composed by mountains and is designed longitudanally by Adda and crossed by the Liro-Mera. All the mountains belongs to Alpi Retiche except for the Splugas’s west part where Alpi Lepontine die.

The main climate is alpine but thanks to altitude and continental nature here several micro-climates exist. Altitude and solar exposure strongly influences temperatures, infact the Retic area with 500-600 meter altitude is warmed by sun, the south part attached to the Orobie is colder and mainly coverd in wood.

Precipitation are more intense moving from the valley floor to the mountain because of wind’s influence coming from Como Lake. Orobic side is much more rainy than the Retic one and winter is drier, indeed the maximum precipitations are registered between may and october. In general it’s a drier area compared to Prealpi and Pianura Padana although snow is common in winter ad it increases with altitude.

The city of Sondrio is settled in the Media Valtellina where Mallero and Adda river Flows, just outside Valmalenco, as all the district is enclosed lengthwise between two mountain chains: Alpi Retiche to the north and Alpi Orobiche to the south.

Sondrio represent the smallest county town in Italy, the territory is just km2. As the rest of the valley the climate is continental with warm summers and cold winters.

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Castle description: The De Piro Castle is located in the peak of a rocky hill (grumo) which has given the characteristic name “Grumello”. The castle can be reached by a secondary road strating from the Strada Panoramica Sondrio.Treviso-Ponte Valtellina. The site is today part of the Comune di Montagna administration, in Sondrio province.

The oldest document describing the castle, coming from Como archives, dates back to 1329-1333 in “Castro Grumelli”. The origins of the castle date back to the Middle Ages. It was probably built in about 1000 as a military outpost with an observation tower in a strategically placed location for defence and for the protection of local villagers. At that time the local community was headed by Consuls who owned it.

The Castke has been built between the end of XIII and the beginning of XIV century by Corrado De Piro. The ghibellin family De Piro, was a rich family who moved to Valtellina because of the war between Milan and Como. From the strategic position of the construction it was easy for the lords to tease the city, until the pop-

ulation rised under the guide of Tebaldo de Capitani conquered the Castle.

In the early 1300’s, the Consuls presented the Castle to Cardinal Guglielmo Longo who had been elected to the cardinalship by Pope Celestino V. During this period, the castle witnessed many bloody battles. In the 1400’s, the Castle was once again caught in the struggle between the Dukes of Milan and the Republic of Venice. It was initially conquered by Pandolfo Malatesta, general of the Duke of Milan, Gian Galeazzo Visconti. In 1335, after Como lost the war, became property of the new lords, the Visconti family. In 1521 it was destroyed under attack of Grigioni, the lords of the next valley, who didn’t want the fortress to became a warning for them.

After being destroyed the Castle was bought by a wine production company which started to produce wine in the hill where the Castle is. In 1987 the company administration decider to leave the Castle to the Italian Environmental Found (FAI).

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Actual state: Castle Grumello is a rare example of “castello gemino�. The remains of two castles are connected by a very irregular path and between the two main structure it is still possible to recognize the foundations of other rooms.

It’s probable that between the two castles once there was an enclosed corridor, allowing the connection. The oriental part consists in a squared, well preserved tower with wall of different heights. This complex was clearly a military fortress, while the occidental structure presented spaces more coherent with a living function. Both the structures have towers, they are made of stones and lime mortar and lots of their foundations are directly in the lower rock. The Castle foundations reside in a rock compound called Scisti di Edolo (micascisti, mainly muscovitici), which belong to the Alpi Orobie.

The panoramic view form the castle is really breathtaking, showing both the valley, the Adda river path and all the vineyards in the terraced hills.

Recent intervention: When FAI started to deal with the Castle in 1987, a plan for the castle conservation was made. An accurate survey, both geometrical and architectural has been done in 1989. The survey allowed the production of plans and elevations both in 1:200 and 1:50 scale. They were made in order to understand the condition of the site and start planning the restoration. The project regarded the castles as well as the landscapes and the natural elements of the site. Stones were consolidated, lime mortar were renewed and the top of the walls repaired. The interior spaces were cleaned from grass and vegetation.

Area of intervention: The area we analysed is the part between the two castles. It used to be a passage connecting the two main bodies and some rooms to accommodate guests. Nowadays it is clearly the most damaged part. The only remains consist in foundations, however the shape of the rooms and the position of the wall is still visible. The FAI intervention since 1989 for this central part was expressed by the presence of some furniture and signs asking the visitors not to climb the foundations. Since the walls are all very low (foundations), the condition of the compound was clearly critical from the beginning both in vertical and horizontal analysis.

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TARGET: The survey and the following representation give precise information regarding the actual conditions of the structure, referred to the kind of activity and use which are connected to the specific site. The survey is, infact, an analysis made to get the complete comprehension of the object, both of the visible and non-visible parts, internal and external. We need to understand the site in order to be able to organize a conservation project after our survey.

Methods: The survey of an architectural body asks for different investigations. Firstly, the investigation is both visual and by instruments. Secondly, it regards different fields of knowledge and expertise. The first one is about the building techniques, materials and structures, the second one refers to the understanding of the historical age and the architectural features. Finally it is also required to analyse the relationship of the body with the surrounding (its context) and the other buildings.

Describing our practical experience, the survey has been done in five different days of site visiting. It was firstly organized a basic metric survey in order to understand scales and dimensions we should have to deal with. This survey was done based on a plan of the site which is the one of FAI. After this general geometrical survey we moved toward a more detailed metrical analysis in order to be able to draw differences in heights and angles.

Then we started the visual survey, based on materials. The materials were mainly stones, mortar and vegetation. So we managed to study the typical stone of Val Malenco and we visited the Stone and Minerals centre in Sondrio to get explanations about particular stones. At the same time we studies the characteristic vegetation of the area to recognize plants and small shrubbery. The third step was to map all the surfaces of our complex

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trying to determinate all the kinds of degradation and deterioration. This survey was once again visual with the support of books and edotypes , while for names and types of degradation we based the analysis on the ICOMOS dictionary. Our approach was so base on three different thematical survey, and we also wanted to deeper the analysis also with three different scales. The first one, as explained at the beginning, served as a guideline to understand how to act in the others. The second was teh detailed general survey of the whole area. The third was a very detailed zoom on a particular slice that we indicated as the most damaged.

Example of edotypes taken during the survey regarding materic and degradations:

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Laser distancemeter:

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Castel Grumello (So)

GoPro Hero 3 Black Edition.

It is a video camera born mainly for sport porpouses characterised by a wide angle lens capable of 172°, it has been implemented for the use in several sectors. It takes 12 Megapixel pictures FullHD videos. It can be emoted commanded by smartphone and easily linked on several supports. In our case we used to make video ad reach not walkable areas.

Digital reflex cameras: Pentax K-x, 12MP, lens: 55mm f1.8 The fixed lens of this camera is quite narrow but has little optical deformation: this enhance the capability to take good pictures for collages with faithful dimensions.

Nikon D3200, 24Mp lens: 18-55mm f3.5/5.6

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THE SURVEY: The various phases of the survey can be summarized in: Recognition of the case of study and choice of survey techniques Survey Graphic transposition of the survey Object analysis through the lens of the survey and the representation, the historical and bibliographical documentation, archives In our study case the survey was direct, using simple measurement instruments. The metric survey is thou characterized of two phases. One on site, consisting in the measurements, the draws of the edotypes and the information collection. The other is the production of the technical drawings.

General metric edotype:

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Horizontal survey

Detailed metric plan

We decided to start our survey from the horizontal analysis of the dimensions. We encountered a problem considering the dimension of the site and the distance between the two castles. We didn’t have the instruments to control and measure both the distance in horizontal and the different in height in the whole space between the two compounds. We decided then to start from defined points (STRONGHOLDS) that we underlined in our 1:100 survey and start the trilateration from them.

For the trilateration we used both a laser distancemeter and a tape distancemeter, so we could measure the same distance with different instruments, litating the mistakes.

The trilateration method consists in the determination of a point thanks to the properties of every triangular structure. In geometry, trilateration is the process of determining absolute or relative locations of points by measurement of distances, using the geometry of triangles. In two-dimensional geometry, it is known that if a point lies on two circles, then the circle centres and the two radii provide sufficient information to narrow the possible locations down to two. Additional information may narrow the possibilities down to one unique location. It is possible to define the point based on the length of the triangle sides. We tried to make all the triangles as equilateral as possible and to take more measurements (coming from different triangles) in order to have always more than one triangle coming to a point.

We proceded measuring the perimeter our study case first, than, based on the point we found of the perimeter we moved inside the foundations site and mesaured with more details.

After all the measurements with these instruments we used the points we determined of trilateration as basic points where to poition our pictures. The next step was infact a photoshooting of the entire architectural body in horizontal, in order to collect all the detailed information.

This technique consisted in a series on pictures taken maintaining the camera lens perpendicular to the surface of the complex and 50 cm distant. The pictures were taken every 50 cm. All the pictures collected have been afterward put together recreating a big pictures of the plan from which we could really precisely define the position, nature and condition of each single stone.

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Metric plan, trilateration:

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Vertical survey: The vertical survey consists in the facades and sections determination. The procedure we followed is connected to the horizontal survey. After we determined the strongholds, in the edotypes we pointed many other spots from which the elevation has been measured with an appropriate instrument (longimeter). With this method we have been able to indentify the difference in heights of each spot we pointed and so the general slope of the site, for which the precision and accurancy would only be based on the numebr on points measured.

After collecting all the points and their relative height (referred to the first point measured at the base), we had again a sort of vertical and horizontal framework in which we can insert a collage of the facades. All collages once again were made by collecting all the pictures made at the same hight and the same distance from the surface

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Mesurments have been taken by tight distances in order to be as accurate as possible.

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Castel Grumello (So)

Photogrammetric survey The theoretical principles of perspectical representation. if applied to photography, are called photogrammetry.

The caption of a photo frame is possible (considering it’s s central perspective) if we do not consider possible mistakes because of the curvature of the lens. It is proved that a picture of an object is identical to the perspective of the object itself, made with the focal point in the centre of the optical system of the camera. Once considered the perfect compatibility between photography and graphical representation, it must then be possible also to use the theorical principles to get the real measurement of an object from its picture. The photogrammtry has been foundamental for all kinds of survey we did. We already described the used of the camera in the metric survey. Once we collected all the pictures, we made the collages of the single sides and the plan by overlapping pictures and straightening them. For this particular operation we used the software RDF, the version for students, and we mainly adopted the geometrical straightening. In other cases we also used Photoshop CC to correct the perspetive of the pictures.

We also used the videocamera GoPro to make short movies of the pavements of our site and to reproduce the exact movements we made with camera in order to have a possibility to check the plan and the elevations once again.

Collages of the plan:

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Problems encountered during survey: The first problem we encountered was questioning how to connect the whole complex together since we didn’t have any georeferetiation.

Another problem was related to the areas in which we could and could not go in order to survey. Both for problems of safety and private property Third problem, relate to the first one was the hard work of determining the actual difference in heights of each point, since the ground in really irregular. We didn’t manage to measure precisely and in 3D how the surface goes.

Comments and considerations: The metric survey would generally focus on the architectural details in the end. Unfortunately our study case consists in the remains of foundations, so it it impossible to recognize architectural details and ornaments. We decided than to focus our attention in the precision of the whole survey, since it seems there were no principal and secondary parts and not clearly better and worse conserved. Our details have become the stones and the vegetation growing on them.

Collages samples:

Central wall , external view (drawing ref: 6)

East wall , external view (drawing ref: 10)

East wall , internal view (drawing ref: 9) Group 8

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MATERIC SURVEY

Supported by the tools we presented in the paragraphs above we created an accurate survey taking information either from lessons and experts who advised us about manuals (E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc) (Bishop A.C., Woolley A.R. & Hamilton W.R. (1999). Cambridge Guide to Minerals, Rocks and Fossils).

The initial method was a mixture of empiricism and notions, several kind of local stones are present in the valley, as we primary identified the presence of metamorphic and sedimentary rocks. The link between rocks is probably entirely made by hydrated lime.

As the we have just foundation rest we don’t have the presence of other materials except for the vegetation and the furnitures added in the last intervention.

The following analysis were lead with the support of rock professionals met at the Rock Museum in Sondrio.

Petography analysis: Castel Grumello is located on the top a rock prong that explicate some of geophysical features of the area.

Geological, tectonic and morphogentic processes sculptured the area. This hump is made by a rock formation named “Scisti di Edolo” that belongs to alpi Orobiche and not to Alpi Retiche as it would be normal to think.

The big presence of glacier made the rest. This means that the area has rocks coming either from Sondrio and other surrondings area, specially from Bergamo distric.

Sedimentary rocks are types of rock that are formed by the deposition of material at the Earth’s surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle and accumulate or minerals to precipitate from a solution. Particles that form a sedimentary rock by accumulating are called sediment. Before being deposited, sediment was formed by weathering and erosion in a source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers which are called agents of denudation.

Impurities present in these rocks lead to a wide range of chromatic aspect even from the one which are born with the same kind of stone. They are normally recognised and divided according to their origin. In our case study they probably belongs to “calcari” and “dolomie” coming from the head of Mallero Valley; Mallero is a stream originated on the Monte Disgrazia and Passo del Muretto which has an altitude of 2.600m and flows into river Adda just passed the city of Sondrio.

The site has a prevalence of metamorphic rocks either of igneous or sedimentary origin. These rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock — to different temperature and pressure conditions than those in which the original rock was formed. This proExample of sedimentary rock Turbidite

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cess is called metamorphism; meaning to “change in form”. The result is a profound change in physical properties and chemistry of the stone. The original rock, known as the protolith, transforms into other mineral types or else into other forms of the same minerals, such as by recrystallization. The temperatures and pressures required for this process are always higher than those found at the Earth’s surface: temperatures greater than 150 to 200 °C and pressures of 1500 bars. Metamorphic rocks compose 27.4% of the crust by volume.

Granite is probably the most diffused rock in the area. It is a common type of felsic intrusive igneous rock which is granular and phaneritic in texture. The word “granite” comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a holocrystalline rock. The term ‘granite’ also applies to a group of intrusive igneous rocks with similar textures and slight variations on composition and origin. These rocks mainly consist of feldspar, quartz, mica, and amphibole minerals, which form interlocking, somewhat equigranular matrix of feldspar and quartz with scattered darker biotite mica and amphibole (often hornblende) peppering the lighter color minerals. Occasionally some individual crystals (phenocrysts) are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic texture is known as a granite porphyry. Granites can be predominantly white, pink, or gray in color, depending on their mineralogy. By definition, granite is an igneous rock with at least 20% quartz and up to 65% alkali feldspar by volume. Granite differs from granodiorite in that at least 35% of the feldspar in granite is alkali feldspar as opposed to plagioclase; it is the potassium feldspar that gives many granites a distinctive pink color. The extrusive igneous rock equivalent of granite is rhyolite. Some of the kind of rocks actually comes from granitic metamorphosis.

Primary role is played by schist originated either in place and in the valleys close by (specially Valmalenco micascisti). Schist is a medium-grade metamorphic rock with medium to large, flat, sheet-like grains in a preferred orientation (nearby grains are roughly parallel). It is defined by having more than 50% platy and elongated minerals,often finely interleaved with quartz and feldspar. These lamellar (flat, planar) minerals include micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is produced. Schist is often garnetiferous. Schist forms at a higher temperature and has larger grains than phyllite.Geological foliation (metamorphic arrangement in layers) with medium to large grained flakes in a preferred sheetlike orientation is called schistosity.

Serpentine are quite diffused as well in the area and on our analysis case. Here appear mainly with a green colour and fine grain alternatively with fibrous texture and high schistosity or non shist.

Gneiss is another rock widely used in the complex, it is formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks. It is often foliated (composed of layers of sheet-like planar structures). The foliations are characterized by alternating darker and lighter colored bands, called “gneissic banding”.

We recognised several types of gneiss with different chromatism from dark to light grey, some shifting to green or even warmer colour as pink but all referable to metamorphic rocks.

Example of metamorphic rock Gneiss

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List of rocks and material classified on site: Granite: Common type of felsic intrusive igneous rock which is granular and phaneritic in texture

Oxidized granite: Granite showing a superficial presence of metals.

Micascisto: Methamorphic rock mainly constitued of mica and quartz. It is another kind of granite.

Serpentine: Greenish, brownish, or spotted minerals commonly found in serpentinite rocks. They are very common in Malenco Valley.

Marble: Non-foliated metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.

Sandstone: Also known as arenite. It is a clastic sedimentary rock composed mainly of sand-sized minerals or rock grains.

Concrete stone: artificially agglomerated stone, different compositions.

Gneiss: High grade metamorphic rock. It is formed by the metamorphosis of granite, or sedimentary rock.

Damaged granite:

Lime mortar: Type of mortar composed of lime and an aggregate such as sand, mixed with water.

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Other materials classified on site: During our surveys we decided to classify even the materials that did not direct belong to the structure specially related to the ground because they actually are in a strict relation to the site as here does not exist an internal environment in contrast to an external but it is all in one.

Local vegetation is characteristic and FAI did a good job with classification though we referrer to it.

In order to suit the purpose of our investigation we decided to classify biolocical intervention in: grass, botanic plants, alga, moss and saxifragaceae.

Grass: Erbaceous plants with narrow leaves growing from the base.

Botanic plants: Vegetal living being specially planted on a elevation for aesthetics.

Alga: Microscopic vegetal organisms withoutstem nor leaves which can be seen outdoors and indoors, as powdery or viscous deposits (thickness: tenth of mm to several mm).

Moss: Vegetal organism forming small, soft and green cushions of centimetric size. Mosses look generally like dense micro-leaves (sub- to millimetric size) tightly packed together.

Saxifragaceae: Vegetal organism gnerally growing from the ground or between stones. The Latin word saxifraga means literally “stone-breaker�

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Materic plan:

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Granite

Marble

Lime mortar

Botanic plants

Oxidized Granite

Sandstone

Buca pontaia

Alga

Micascisto

Concrete stone

Gravel

Moss

Serpentine

Gneiss

Grass

Saxifragraceae

Conservation studio Report

Castel Grumello (So)

Materic elevations:

Group 8

Granite

Marble

Lime mortar

Botanic plants

Oxidized Granite

Sandstone

Buca pontaia

Alga

Micascisto

Concrete stone

Gravel

Moss

Serpentine

Gneiss

Grass

Saxifragraceae

Conservation studio Report

Castel Grumello (So)

DEGRADATION SURVEY

Degradation survey is an essential part of this work, infact without a proper understanding of the existing situation we would risk to loose the historical heritage. A national standard comes in our help: UNI Normal 88.

This deals with natural and artificial rocks pointing all the degradations that can be seen by eyes. We referred at the same time at the ICOMOS Illustrated glossary on stone deterioration patterns.

The survey underlined the presence of recent intervention (15 years old) which altered the conservation status exposing our part of the castle to major degradation. Here are the aggressions we have detected on the area (images reffers to ICOMS): Anthropic degradation: degradation it manifests with some parameter modification regarding the colour such as hue, value and saturation. It could be localized or diffused, in our case it is mainly referred to the presence of iron oxides in the rocks.

Crack: Individual fissure, clearly visible by the naked eye, resulting from separation of one part from another. The mortar weaknesses lead to few fractures with the potential detachment and lost of parts.

Concretion: Kind of encrustation having a specific shape: nodular, botryoĂŻdal (grape-like) or framboĂŻdal (raspberry like). Concretions may even have conic shapes of form drapery-like vertical sheets. Stalagmites and stalactites are kinds of concretions. In general, concretions do not outline, contour the surface of the stone, and are of limited extent Crust: Generally coherent accumulation of materials on the surface. A crust may include exogenic deposits in combination with materials derived from the stone. A crust is frequently dark coloured (black crust) but light colours can also be found. Crusts may have an homogeneous thickness, and thus replicate the stone surface, or have irregular thickness and disturb the reading of the stone surface details.

Crumbling: Detachment of aggregates of grains from the substrate. These aggregates are generally limited in size (less than 2 cm). This size depends of the nature of the stone and its environment.

Chromatic alteration: it manifests with some parameter modification regarding the colour such as hue, value and saturation. It could be localized or diffused, in our case it is mainly referred to the presence of iron oxides in the rocks.

Detachment: continuity between materials is being lost and generally it is a situation that occur before the fall of the material. Normally it refers to plasters and mosaic, in our case rocks on the top are more affected as it is demonstrated by the cracks happened in some areas on top.

Disgregation: little mechanical stresses provoke grains or crystals detachments. It is quite diffuse in the mortar especially on the top and in presence of vegetation.

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Castel Grumello (So)

Delamination: consists of detachment along bedding or schistosity planes, not necessarily orientated vertically. In delamination, mechanical overload is not noticeable. Delamination is transitional to splitting Efflorescence: generally whitish, powdery or whisker-like crystals on the surface. Efflorescences are generally poorly cohesive and commonly made of soluble salt crystals. We have some little examples due to the stone realise of salt.

Erosion: material removal from the surface due to different processes -abrasion, usage, chemical or biological). Stones here are raw so it is difficult to define this.

Encrustation: it manifests with some parameter modification regarding the colour such as hue, value and saturation. It could be localized or diffused, in our case it is mainly referred to the presence of iron oxides in the rocks.

Missing part/lacuna: due to the fall and lost of parts. It is used when the dictionary doesn’t present any other possible definition.

Patina: Chromatic modification of the material, generally resulting from natural or artificial ageing and not involving in most cases visible surface deterioration.

Pitting : Point-like millimetric or submillimetric shallow cavities.

The pits generally have a cylindrical or conical shape and are not interconnected, although transitions patterns to interconnected pits can also be observed.

Staining: kind of discolouration of limited extent and generally of unattractive appearance.

Example: iron oxides are driven by water from the rusting railing, and induce the development of a brown staining on the underlying stones.

Vandalism: deliberately mischievous or malicious destruction or damage of property.

Grass: herbaceous plants with narrow leaves growing from the base.

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Castel Grumello (So)

Presence of vegetation: Grass and little plants are present all around the wall rest.

Alga - bio patina: Chromatic modification of the material, generally resulting from natural or artificial ageing and not involving in most cases visible surface deterioration. In our case we deal with biological patina composed by a soft, thin and homogeneous layer by micro-organism, moss... Diffused on all facade especially on mortar.

Moss: Vegetal organism forming small, soft and green cushions of centimetric size. Mosses look generally like dense micro-leaves (sub- to millimetric size) tightly packed together.

Saxifragaceae: Vegetal organism gnerally growing from the ground or between stones. The Latin word saxifraga means literally “stone-breaker”

Survey process: Our case study is represented by the central part of Castel Grumello which once probably was a residential part, nowadays we can appreciate the presence of the foundation of that ancient settlement; we have several walls that probably reveals the presence of 3 rooms and the strict relation with the mountain infact the castle lay down directly on rocks.

Metric Survey: The plans that we have received allowed us to proceed with a special accuracy, infact after the due verification about real measures and quotes we proceeded investigating the origin and the historical stratification of our zone.

The castle has lived long without being touched but around lot of changing happened. The walls surrounding the area are probably and an inheritance of the several wineyard around, infact the construction method appear to be different: it is dry stone (that’s what suggest us it is from wine yard, they build like this to allow the flow of water) the castle instead is made by stones aggregated with mortar.

Despite the destruction of the castle by Grigioni we can consider to be lucky cause the conservation is clear by any other later modification (except for the wall we have treated in the previous paragraph).

The survey was led using different kind of supports starting with a direct investigation using eidotypes (by the Greek eìdon, see, and tupòs, sketch) drawn by us.

This investigation required the use of these instruments: _A laser distance meter to measure longer distances and slopes _A rigid meter for vertical measurements _A tape meter for most of the flat distances and trilaterations.

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Castel Grumello (So)

Several notes about damages during the surveys were of the great help, nevertheless we decided to support them taking many pictures. Once at home we made collages both plan and elevations to have a better record of what we have seen. This was of great help when we met rocks experts at the rock museum in Sondrio as they helped us with a more conscious observation of the stones presents in our site.

We availed ourself with the use of a GoPro camera to record a video around the castle.

Materic survey: Degradation is strongly related to the composition of the construction that is entirely made by stones. The direct consequence is that we have an extremely tough material but weak connection due to the mortar. The structure lays on the rock itself and it is characterised by the presence of local stones either metamorphic and sedimentary as described in the previous chapter.

This stones can be attacked by vegetation but are not sensible to deep degradations.

Degradation survey: The site is highly exposed to weather conditions so it presents several damages and show the signs of the previous intervention.

The main risk is represented by the close presence of vegetation which attacks the structure settling inside the mortar and by the anthropic use. The area is not protected and people and kids are allowed to play on it creating additional stresses.

Disgregation is diffused but we highlighted higher level of risk in the east wall which actually is the tallest one and is characterised by a different height on his two facade due to the difference in the ground level.

All the north faced is covered with ornamental vegetations and appears to be solid. The bottom part it is in dry stone and is probably part of the intervention happened 15 years ago.

The south part is influenced by wineyard walls once again in dry stones, but it mixes with a part that could have been included in the castle. Degradation here mainly refers to the vegetation action.

Micro cracks are present all around but significant one could be seen just in the east wall on the top rocks, these leads to some detachments but we don’t observe any dangerous situation as the wall are short, nevertheless we need to plan a constant intervention if we don’t want to loose the manufacture in few decades.

Several chromatic alteration are present but these could be considered mainly as a characteristic of this rocks, infact the oxydes are naturally present in the rocks and we don’t appreciate other significant change.

Croncretion is widely diffused on the walls but it is a superficial so the routine maintenance by cleaning (nowadays almost totally absent) would be enough to prevent this phenomena.

Shadowed sides are more affected by biological patina’s attack, in particular the diffusion of moss should be controlled.

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Castel Grumello (So)

Degradation plan:

Group 8

Anthropic

Detachment Disgregation

Missing part/ lacuna Patina

Presence of vegetation Alga - bio patina

Crack Concretion

Delamination

Pitting

Moss

Crust

Efflorescence

Staining

Saxifragaceae

Crumbling

Erosion

Vandalism

Chromatic alteration

Encrustation

Grass

Conservation studio Report

Castel Grumello (So)

Degradation elevations:

Group 8

Anthropic

Detachment Disgregation

Missing part/ lacuna Patina

Presence of vegetation Alga - bio patina

Crack Concretion

Delamination

Pitting

Moss

Crust

Efflorescence

Staining

Saxifragaceae

Crumbling

Erosion

Vandalism

Chromatic alteration

Encrustation

Grass

Conservation studio Report

Castel Grumello (So)

Comments and considerations: The central part of the structure have been well preserved as it was in origin but it is basically made by walls crest which are by definition the weakest part. Materials are not in a risky status so the main intervention to preserve the actual status is a regular cleaning and a maintenance of the lime which is the part that guarantee the integrity of the walls.

Historic investigation: The current site situation is quite unique and interesting as history gave back to us the rest of the castle just as it was after the destruction led by Grigioni as the middle part have been buried for a long time and the rest was just a ruin.

In the degradation survey we highlighted the fact that just few alteration were made by inhabitants that were cultivating Grumello’s soils. Modification so regarded the boundaries wall to the north and to the south. North wall have been consolidated during the recent restoration while the south, probably, have been modified by wineyard workers in order to arrange terraces.

We observe wall joints, some holes that looks too wide to be considered buche pontaie and an arch totally integrated into the new boundary structure.

No sure conclusion can be actually stated but it led us to two different hypothesis. The wall joint and the arch could simply represent structure reinforcement as the soil is extrimely solid due to the presence of rock but at the same time is very irregular and maybe needed deeper foundation in some points. Second hypothesis is that the castle was wider than what appears today and there were hosted some rooms for servants -that were normally on the basement- or for storage purposes. Holes in the wall have been strongly modified (and the internal part filled with rock material) but they could have been old windows.

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Castel Grumello (So)

BIBLIOGRAPHY Professor’s lectures and meeting with professionals have been the base of our work, though we consulted these sources: Books

“Per il restauro del castello de Piro al Grumello” FAI

Mario Docci, Diego Maestri. Manuale di rilevamento architettonico e urbano. Bari: Laterza Editori, 2010.

“Raccomandazioni NorMaL-1/88. Alterazioni macroscopiche dei materiali lapidei: lessico”, CNR-ICR, 1990, Roma

E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc

Bishop A.C., Woolley A.R. & Hamilton W.R. (1999). Cambridge Guide to Minerals, Rocks and Fossils

ICOMOS Monuments_and_Sites_15_ISCS_Glossary_Stone

Websites

www.comune.sondrio.it/site/

www.valtellina.it www.icomos.org/en/

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