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QualityControlManualforStoneCladdingFacades

ManuelPrataRibeirodaCosta

M.Sc.ThesisExtendedAbstract

2011


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1Introduction

Theaimofthiswork isthecreationofaQualityControlManualfornaturalstone inbuildingsfacadescladding.Thismanualisintendedtocontributetothereductionoftheanomaliesandpathologiesthat

mayoccurduringthelifetimeofthebuildings,causedoramplifiedbyabadchoiceormisapplicationofthecladdings.

Outsidethescopeofthisstudyare,therefore,alltheworksthatarenotperformedonsite,suchasthe

draftdesignoftheanchorsthatmustalwaysbedonepreviously.

Naturalstoneisoneofthematerialsusedinbuildingconstruction,foralongtime,duetoitsdurability,strengthand the finalaestheticqualityof thebuildings. Since themorewidespreaduseof reinforcedconcrete structures, in the twentieth century, the stone turned to be used almost exclusively as

cladding, losing its roleof structural elementof thebuilding.Natural stonehasnot lost, however, itsmostappreciatedfeatures,suchasthe"nobility"ofthebuildingandqualityasacladdingmaterial,beingthereforestilloftenusednowadays.

Currently,thereisawiderangeofoptionsavailableforchoosingthetypeofstoneandofitsfinishing,allowingmanydifferentcladdingstypes.Theevolution,overtheyears,ofstonecladdingwentalsoalongwithasignificantprogressofthetypeofanchorsusedtosupportthestonespanels.Differentdirector

indirectanchoragemethodsforthestonesarenowavailableandthereisasuitablesolutionforanykindofstoneorbuilding.However,eventaking intoaccountgooddurabilitycharacteristicsof thestone, itappears that some relatively recent buildings,with stone cladding, present anomalies or pathologies.

Anyanomaliesinabuildingcangiverisetoproblems,butwhentheseanomaliesareonthefacades,thesituationbecomesmoreserious.Theanomalieson the facadesdamage, inmostcases, theaestheticsqualityofthewholebuildingandcancauseproblemsofinfiltrationandpoorinsulation.Whendealing

withstonecladdingsintheexteriorofthebuildingsthereisanothersituationthatcannotbeneglected:theriskofdetachmentandfallofstonesthatcanendangerpeople.Therefore,pathologiesanddefectsinexteriorfacadescanbeextremelyserious,soitusextremelyimportanttominimizetheircauses.

Whateverthecladdingtechniques,afinalresultofgoodqualityanddurabilityrequiresthecomplianceofbuildingproceduresspecifictothenatureofthemasonrybackupwherethestoneistobeinstalled,thechosenanchoragemethod,thetypeofstoneused,amongother.However,oftentheseprocedures

are not followed, either because they are not properly known or due to economic reasons, lack oftrainingofinstallers,lackofsupervisionorotherreasons.Theincorrectapplicationofastonecladding,using a technique well known for its good results, may compromise the final outcome. These facts

severely penalize theuseof natural stones, disseminate incorrect information about thedurability ofthestoneandcreatepreconceptiontopotentialusers.Manyoftheundesirableaestheticandfunctionalmutations observed during the lifetime of a building were stone cladding was used are not directly

relatedtothestonesthemselves,buttotheinappropriatechoiceorpoorinstallationoftheanchoragesystems. These kinds of errors can completely cancel out the potential benefits of this buildingtechnique,givingraisetosignificantfutureexpensestocorrectthedefects.


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A good understanding of the procedures outlined in the Manual requires prior knowledge of thedifferent types of natural stone – igneous, sedimentary and metamorphic rocks ‐ and their main

characteristics‐porosity,compactness,permeabilityandhygroscopicity.Thedifferenttypesoffinishesthatcanbeappliedtothestones‐polished,bush‐hammered,roughsawn,thermalfinish,sandblasted,smoothedand scratched ‐ shouldalsobe considered. To identify these characteristicswe can relyon

testsperformedaccording to thePortuguese standardNPEN1469.These testsallow toevaluate thesuitabilityof thecladdings to theconditionsunderwhich theyareusedandto the functions theywillperform.

2Typesoffacades

Thereareseveralkindsofstonecladdings,dependingonthenatureof theanchoragesystemusedtosupportthestonepanels:methodsofdirectanchorage(bondingandsealing)andmethodsof indirectanchorage(withstaplesandpointsofmortar,withgrout‐inanchorsandmetalsupportsubstructure)are

themostused.

2.1Directanchoragemethods

This technique is characterized by the usage of a continuous anchorage product (such as mortar orcement‐epoxyresin)bindingthestonesurfacetothemasonrybackupwherethestonewillbeapplied.

[1]

It is important to be aware of the correct ways of application and restrictions to the use of thisanchoragemethod in order to obtain good quality results. French regulation on buildingswith stone

claddingfacades"CahiersduCSTB(CahiersduCentreScientifiqueetTechniqueduBâtiment)”containsstandards and guidelines that are followed by many installers and producers of materials for theapplicationofstone.Theserulesdeal, for instance,withthethicknessandmaximumsizeofthestone

panels,themaximumheightatwhichtheycanbeinstalledandanchoragematerialsspecifications[2].

Thereare twoanchoragetechniquescommonlyusedtobindthestonepanel to themasonrybackup:collagebydots(theoldertechnique,nolongerused)andcontinuousanchorageofhigh,mediumorthin

thickness(thethinoneisthemoreoftenusedtechnique)[3].

Accordingtothechoiceofthebindingmaterialemployed,twotypesofanchoragecanbedistinguished:bondingandsealing. [4]Thebondinganchoragemethodusesadhesives suchas cementpaste,epoxyresinsormortar.[5]Thesealinganchoragemethoduseslimebasedmortarorwhitehydrauliccement.

Usingthismethod,thelikelihoodoftheappearanceofstainsislowerthaninthecasewheretraditionalcementsareused.[5]

In all methods it is advisable to use a deformable binding material settlement, consistent with the

expansionandcontractionofthestonepanelcausedbytemperaturechangesanddeformationofthefacade.Thesephenomenamaybeamplifiedwiththeincreaseofthedimensionsofthestonepanels.

Nowadays,thismethodtendstobeusedinsmallareassuchaswallsand,lessfrequently,inthecladdingofentirefacadeswheremethodsofindirectanchoragearebettersuited.[6]


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2.2Indirectanchoragemethods

Thistechniqueischaracterizedbythepresenceofseveral isolatedelementsofanchorage,bindingthe

stonespanelstothefacade.Theseelementsareusuallymadeofmetalandallowtheabsorptionofthedeformationsthatthestonepanelsmightsuffer.Therefore,thecladding,whichismorefragilethanthesupportinrespecttodeformations,sufferslessstress.Thistypeofanchoragehastowithstandboththe

vertical forces (such as theweight of the stonematerials) and the horizontal actions (such aswind).Thesemethods create a free space between the stone panels and the building itself. Air circulationthrough this cavity avoids the concentration of moisture and condensation, keeps the natural stone

panelsdry,providingnaturalisolationforthebuilding.[7]

The anchors used in the indirect method can be classified into three groups: staples and points ofmortar,grout‐inanchorsorsupportsubstructure.[7]

Severalfactorsshouldbetakenintoaccounttochoosethebestanchoragemethodforeachcase,such

asthenatureofthefacade,thesize,characteristicsandweightofthestonepanels,theexistenceornotofthermalorsoundinsulationbetweenthestonesandthebuilding,theareaofthefacade,thepriceoflabour,etc.

There are some rules common to the three anchorage methods, namely in what concerns the

characteristicsofthestonestouse(suchasitsminimumthicknessandmaximumsize)andthequalityofsteelanchors(dependingonthenaturalfeaturesoftheplace).

For the proper application of indirect anchoragemethods, the choice of the specific location of the

bracketsinthefacadeisveryimportant:toavoidtensiononboththeanchorsandthestonepanelitself,thepanelcannotbeanchoredtotwoseparatewalls,thatmaysufferdifferentdeformations(closetoexpansionjointsforexample).[8]

2.2.1StaplesandPointsofmortar

Thisparticularmethodof indirectanchorageconsists inthefixingof thestonespanels tothebuildingwall using staples made of circular section wires. The points of mortar are needed for the properfunctioningof thestaplesandtoallowtheadherenceofthepanelstones.Thewires,usuallymadeof

stainlesssteel,duetoitsdurability,arewrappedinmortar.

This method is not compatible with the application of a continuous thermal insulation in the spacebetweenthewallandthepanels,duetothepresenceofthepointsofmortar.

Usuallythemethodconsistsintheuseoffourstaplesperstonepanel:twostaplesforsuspensionandtheothertwoforpositioning.Thestaplesofsuspensionareusedtosupporttheweightofthepanelandareusuallyplacedontheundersideofthestone.Thestaplesofpositioningcanbelocatedonthetopor

onthesidesofthepanel.Tofixthestaplestothestonespanels,itisnecessarytodrillcircularholesontheedgesofthestonestoinsertthestaples.


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2.2.2Grout‐inanchors

Inthismethod,thestonepanelsareanchoredtothebuildingswallsusingmetallicelementsthatmay

differinshape,sizeandotherfeatures.Thesebracketsarefixedtothewallsthroughmechanicalfixingmethods such as screws (Figure 2.1) or through the use of mortar or cement (Figure 2.2). Grout‐inanchorshavedowelpinsthatareinsertedintoholesdrilledonthetopofstonepanelstopreventthem

frommoving.

Fig.2.1 Fig.2.2

Fig.2.1‐Examplesofbodyanchorusingmechanicalfixingmethods[9]

Fig.2.2‐Exampleofgrout‐inanchorfixedwithmortarorcement[9]

The choice between these two methods depends, essentially, on the nature of the building facade

wherethestonepanelwillbeapplied.

Usuallyeachstonepanelisfixedtothewallusingfouranchors.Twoofthemareplacedinthebottombaseof thehorizontal faceof the stone; theyhave thedual functionof supporting theweightof the

stoneandrestrictitsthehorizontaldisplacements.Theothertwoareplacedinthetophorizontalfaceof thestoneandrestrict thehorizontaldisplacements. [10]Alternatively, thebracketscanbe fixed tothepanelstonesbytheverticalfaces.

Thistechniqueofcladdingallowsthebenefitsofthermalinsulationinthespacebetweenthestonesandthe building facade, if installed before the anchorage of the elements. In this case, the insulation isusuallymadeofextrudedpolystyrenefoam,suchasWallmate.

The jointsbetweenthestonepanelscanbe filledusingelasticmaterials [4]orcanbe leftopen if the

facadehasbeenpreviouslywaterproofed[6].

2.2.3SupportSubstructure

Underthismethodthestonepanelsarefixedtothewallsusingametallicstructurethatconnectsthecladding to the building facade (figure 2.3). Thismethod allows the installation of heavier and larger

stone panels than the methods previously described. Nowadays the structure is made of metallicmaterials such as stainless steel. The anchorage of the stones to the structure is performed throughmechanicalmethods.Thestructureisfixedtoatoughareaofthebuildingfacade(usingmetallicanchors

and cementormechanicmethods suchasbolts). This structure consists of a gridof vertical and / orhorizontalprofilesthatcanbeadjustedtofittostonesofdifferentsizes.


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Fig. 2.3 ‐ Example of a support substructure consisting of vertical and horizontal grid profiles wherestonesaresupportedbyrails[11]

This method possesses attractive properties not only because it allows the possibility of thermal

insulationbutalsobecauseitcanbeusedinawiderangeofsituations.Forinstance,somesystemsonlyneedtobeattachedtothestructuralelementsofthebuildings,whenevertheconditionandthenatureofthebuildingswallsarenotadequate.[11]

Thefollowingtable(Table2.1)showsthecompatibilitybetweensupportsandstonescladdingmethods.The data of this table were compiled from the information in the "DTU 55.2" (French technical

regulationsonstonecladding)[12]and"DescriptionandGeneralClassificationofCladdingformasonryandconcretewalls”[13].

AnchorageMethodsStaplesandmortarpoints Grout‐inanchors Support

substructure

Materialofthebuildingwall

Usingmortar

Mechanically Usingmortar Mechanically

Concreteorreinforcedconcrete

Yes Yes Yes Yes Yes

Lightweightconcrete Yes (1) Yes (1)e(2) YesBricks (3) (5) (3) Yes

Concreteblocks (3) (5) (3) (5) YesAutoclavedcellularconcreteblocks

No No (5) (5) Yes

Naturalstone Yes (5) Yes (5) Yes

Table2.1:Compatibilitybetweensupportsandstonescladdingmethods[12]and[13]


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(1) Procedureacceptableiftheconcretestrengthat28daysexceeds15MPa[12](2) This anchorage method requires conducting a detailed description in the specification and an

engineering design. If the characteristics of the buildings walls are not fully known, it is requiredimplementationofpullouttestsonsite.[12]

(3) Thisanchoragemethodcanbeappliedonlyifsomespecificrequirementsrelatedtotheuseofmortararefulfilled

(4) Thisprocedurecanonlybeapplied if the jointsbetweenpanelsare leftopenor filledwitha resilientmaterial

(5) In the "DTU 55.2" (French technical regulations on stone cladding) this type of attachment is onlyacceptableifadetaileddescriptioninthespecificationandanengineeringdesigniscarriedout.However

the"DescriptionandGeneralClassificationofCladdingforMasonryandConcreteWalls”[13]refersthatthistypeofanchorageisnotfeasible

3Constructivemethods

The elaboration of the design for buildings with stone cladding must specify the method of stoneanchorage,thecharacteristicsofthestones(forinstancethetypeofstoneanditsthefinishing,thetype

ofanchors,theinsulationtype,thesizeofthejointsbetweenstonespanels)aswellasallotherrelevantaspectsthatguaranteethattheminimumsrequiredcriteriaforsafetyanddurabilityarefulfilled.[6]

3.1Directanchoragemethods

Whenusingcontinuousanchorageproducts,thefirststepistheassessmentofthestateofthebuilding

facadetocheckifitisclean,withnodustoroils[14]andreadytoreceivethestonepanels.Besides,thedryingtimeofmaterialsused inthefacade(mortars)mustbefollowed inordertopreventshrinkage,stonesstaininganddeteriorationoftheadhesive[15].

Whenmortarsareusedasananchorageproductitisimportanttoensurethattheproperchoiceofthemortarshasbeenmadeintermsofgoodadherencetothestone,itsabilitytosupporttheweightofthestoneanditsadequacytothelocalweatherconditions.[16]Priortoitsuse,thebuildingfacadeandthe

stonepanelsshouldbemoistenedtoincreasetheresistanceofthebind[2].

Under thismethod, theanchorageproduct shouldbespreadbothon thebuildingsurfaceandon thebackofthestonepanel,insmallareas,topreventexceedingthetimeofworkabilityoftheadhesive.Thethicknessof the layershouldbe inaccordancewith therecommendationsof themanufacturerof the

mortar.[14]

Theprocessofstoneanchoragemuststartfromthebottomtothetopandfromonesideofthewalltotheother [3].The jointsbetweenthestonesmusthaveaminimumthicknessof4mm[2]andwillbe

filledwithelasticmaterialsatleast48hoursaftertheendoftheanchorage.[6]Inthecaseoflargeareasitcanbenecessarytoaddadditionaljointsinthesefacades[2]

3.2Indirectanchoragemethods

Whenstaplesandpointsofmortaristhechosenmethod,thefirststepisthemarking,onthebuilding

facade,oftheprecisespotswheretheanchoraretobeplaced.Next,therequiredholesaredrilled(withaminimumdepthof60mmandarecommendeddiameterof40mm),cleanedandmoistened.Theholes


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are then filled and mortar while the points of mortar are done (with a diameter of approximately100mm).Meanwhile,itisrecommendedtopreparetheholesontheedgesofthestonepanels(inthe

axisofthepanelthickness,withaminimumdepthof30mm[4]),andtoplacethestaplesonthestones.Finally, we bind the stone panels to the facade and its staples are inserted on the holes filled withmortar.Thejointsbetweenstonepanelsmusthaveaminimumthicknessof4mm,andcanbefilledwith

elasticproducts[4].

If,alternatively,theselectedmethodisthatwithgrout‐inanchors,thefirststepisalsothemarkingonthebuildingfacadeoftheholestoinsertthedrips(holeswithaminimumdepthof80mmanddiameter

of 40mm). After drilling the holes, theymust be cleaned,moistened and then filledwith fast dryingcementormortar. In thecaseofceramicbricks, themostusual is tousemashsleevesand injectableadhesiveanchors.Itisalsopossibletoapplybodyanchors,usingmechanicalanchorage,suchasmetallic

expansionanchorsincementwalls.Theholesontheedgesofthestonepanelscanthenbedrilled.Thelowergrout‐inanchor, togetherwith its supportpine,canbe insertedontheholedrilledonthewall.Thestonecannowbeplacedontheanchor,makingsurethatthepinesenterintoitsthelowerholes.

Then, theupper grout‐in anchor (with its pin) is put in place and inserted into theupperholeof thebuildingwall.Thejointsbetweenthestoneshaveaminimumsizeof5or6mm[4]and,inthecaseoflarge areas, itmay be recommended to have additional joints. If desired, the joins can be filledwith

elasticmaterials.

Duetotheexistenceofmanytypesofsubstructuressystemsofindirectanchoringitisdifficulttodefinegeneralproceduresforcarryingoutthismethod.Thereforetheinstructionsprovidedbymanufacturersof each typeof anchors are themost appropriate recommendations since they take intoaccount the

specificfeaturesoftheproduct.

4Anomalies–Pathologies

The pathologies in the stone facades represent, nowadays, a serious problem in this type of

construction,forsafety,durabilityandaestheticsreasons.[17]

Inthecaseofdirectanchoragetechnique,themostfrequentpathologiesarethecrackingorthespallingof the panels stones, staining in the stones (which can be caused by the penetration of substances,troughthebuildingwallorthestonesurface,orbythediscolorationofthemineralcomponentofthe

stone itself), efflorescence, and the degradation of the products used to fill the joints between thestones.

Inbuildingwherestonecladdingisdoneusingstaplesandpointsofmortar,pathologiescanalsoshow

up(someofthemsimilartothosejustdescribed).Themostcommonpathologiesincludethecrackingorspallingofthestonespanels,thestainslocatednearthemortarpoint,theflakingofthestoneclosetotheholesdrilledtosupportthepinsoftheanchors,thewaterinfiltrationandtheanchorscorrosion.The

stone cladding techniques using grout‐in anchors or substructure systems allow the construction ofmoreflexiblecladdings,whichcanthusabsorbmoredeformations.However,somepathologies,justasthosedescribed,canstilloccurinthesecases.


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Additionally,whenevermechanicalanchorage,suchasmetallicexpansionanchors,isusedseveralotherdifferent problems may occur when push‐out tests are done on the anchors (such as failure in the

expansionofthebolts,failureofthebuildingwalls,failureoftheboltitselforafailcausedbyadeficientinstallationofthemechanicalanchor).

5QualityControl

Asseeninthepreviousdescriptionofthedifferentconstructionmethods,toensureafinalresultofhigh

quality there are several aspects that should be considered when performing cladding facade. Tosimplify and systematize the inspection of the procedures, a Quality Control Manual should beimplemented on site. This manual intends to ensure that the proper procedures of the cladding

installation are followed, that the stone panels installed are fulfilling their role effectively, that thecladdingrespectsalltherequiredsecurityrulesandguaranteesdurabilityoutcomesconsistentwiththeexpectations.

Thismanual embraces the different stages of the construction process, from the design, through thecorrect applicationof the cladding and to the final quality checks. The aimof themanual cannot be,however, the detection or the correction of mistakes that may have occurred during the structural

designstagesrelated,forinstance,withincorrectchoicesoftheanchoragesorofthesizeandthicknessofthestonepanels.

First, we present the preliminary general checks to ensure that the required conditions to start theworks aremet,whatever the anchoragemethod adopted: check the existence of a detailed cladding

design, the accessibility of workers and scaffolding safety, the existence and usage of adequateprotective equipment and check that requiredmaterials were ordered in adequate quantities. Upon

arrival of thematerials on sitewe should check that they comply the order, are in good conditions,displays the CE marking and the name of the stone. The stones must also exhibit their correct sizeaccording to the tolerancesallowed in theEN1469‐2004 (suchas thickness, lateraldimensions,miter

and flatness of the stone panels as well as the location and size of anchor holes). In what concernsfacades, the required checks concern its flatness, its cleanness andadequacy to receive the cladding.Also,there istheneedtoensurethatthe locationsofactivitiesthatmayproducedustareawayfrom

theareawherethecladdingisbeinginstalled.Oncetheworksareinitiated,theyshouldbecarefullyandcontinuouslysupervised.

Nowwerefersomeadditionalchecks,specifictothedirectanchoragemethod,suchas:verifyingthatthecementofthebuildingsisproperlydriedbeforeapplyingthestonecladding,checkingthatflatness

and the roughness conditions of the walls are appropriate, verifying that each stone panel is notattachedtosupportsofdifferentnature.Concerningtheadhesivematerials,the informationprovidedbytheirmanufacturermustbemetandtheadhesivestripsshouldbecrushed,whenbindingthestones,

to prevent any voids between the stone and thewall. In thismethod, the joints between the stonepanels shouldhaveadequate sizeandshouldbe filledonlyafter thecompletedryingof theadhesivematerialsusedinthestones.Finallytheweatherconditionsmustalwaysbetakenintoaccountduring

theworks.


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Theadditionalchecksneededfortheindirectanchoragemethodsincludethecompatibilitybetweenthecladdingdesignandtheengineeringdisciplinedesigns,aswellasothertechnicalrequirements:ensuring

thatstonesarenotfixedtosupportsofdifferentnature,thatthestonesarelaidhorizontally,thattheholes in the walls and in the stone panels have been correctly drilled, that the size of the joints isappropriateandthatthedryingtimesarefullyrespected.

Aftercompletingtheinstallationofanykindofcladding,weshouldcheckthatalltheworksweremadeaccordingly to the design (allowing for the tolerances accepted), that thematerials in surplus in thejoints have been cleaned and that the areas on top of the facades were protected to avoid water

infiltrations.

6Casestudy

AsacasestudyweselectedabuildinginLisbonwerewecouldobserveseveralerrorsintheapplicationof the cladding. Due to these errors, the potential benefits of indirect anchorage vanished. The

building’s facadeweremaid of “moleanos” limestone panels, attached to themasonrywith grout‐inanchorswherewe could detect some of pathologies already described in this report. Therefore, thiscase study could be used to implement the quality control manual proposed. In this building, long

beforetheendoftheexpectedproductservicelife,importantworkshadtobecarriedoutinvolvingthecompleteremovalofallthestonesandfixinganchorsandtheirreplacement.Thisworkswererequiredby the deterioration of the safety conditions of the building when stones from the cladding threat

falling. This problemwas causedby errors committedduring the cladding installation andnot by thedeteriorationoftheanchorsthemselves.Someoftheseerrorscouldbeclearlydetectedduringthevisitstothisconstructionsitesuchastheincorrectlocationofgrout‐inanchors,theincorrectchoiceandpoor

installationoftheanchorpines(figure6.1),thewrongfixingofthegrout‐inanchorsnearthewindowsandbalconiesandtheunderestimateofthejointsthickness(figure6.2).

Duringtheseveralstepsoftheworksdonetorepairthecladdings,wecouldtesttheapplicabilityofthe

QualityControlManualdescribedearlierasgoodmechanismtopreventerrors.

Fig.6.1 Fig.6.2

Fig.6.1‐Incorrectinstallationofagrout‐inanchor

Fig.6.2‐Jointbetweenstonepanelswithunderestimatethickness


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Conclusion

This studyallowsus to conclude thatmostof theanomalies andpathologies that canbedetected infacadesaredue,mainly,totheincorrectchoiceormisapplicationofcladdingmaterials.Theseerrorscan

takeplaceeitherinthedesignorimplementationofthecladdings.

Inthedesignstage,itiscrucialtocarryoutacompleteanddetailedstudy,includingtheselectionoftheanchoringmethod,thetypeandfinishingofthestonepanels,theaccuratedesignoftheanchorsandan

exhaustivedescriptionoftheconstructionmethods(including,forinstance,thenumberanddimensionsof joints). Inthisstage it isalsorequiredtoensurethecompatibilitybetweenthecladdingdesignandtheothersengineeringdisciplinedesign,toavoiddamagingsteelframesorpipeswhendrillingthewalls

andtoavoidfixingasinglestonepanelontwodifferentsupports.

During the construction, proper training of installers and close supervision of theworks can preventmajorerrors.Thesearekeyconditionstoguaranteetheproperhandlingofmaterialsandthefollowupoftheprojectsaccordingtothecontractspecifications.

TheQualityControlManual,suchastheonedescribed,isanadequateandpowerfultooltopresentalltherequiredchecksthathavetobedone,bothinthedesignandimplementationstages.However,thisdocumentisnotaimedtoreplacethedesignorthedescriptionoftheconstructivemethods.Inthecase

studyconsidered,thismanualprovedtobequiteusefultosummarizeallcontrolstobeperformed.

TheuseofaQualityManualsuchastheonepresentedishighlyrecommended:itdoesnotinvolvehighcosts but can give rise to significant benefits, improving the cladding final quality and reducing the

likelihoodofanomaliesthroughoutthebuildinglifetime,aswellasextraexpenses.

ThisQualityControlManualcanbe furtherdevelopedandotherverificationscanbeaddedwheneverrequired. The study of a wider range of buildings and their pathologies would provide a deeper

understanding of this subject allowing the formulation of a more detailed manual. Additionally themanualcanalsobeextendedtoaccountforothercladdingtechniqueslessfrequentlyused.

Themaintenanceofthebuildingsandtheirfacadesiscrucialtopreservethequalityoftheconstructionand extend their lifetime. Unfortunately, we notice that the maintenance of the buildings is often

neglected, due to lack of awareness or to economic reasons. Therefore, the elaboration of amaintenancemanualforbuildingswithstonecladdingcouldbeuseful,describingthekeymaintenanceoperations recommendedaswell as their frequencyandwouldbeuseful complement to theControl

QualityManualpresentedhere.


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