7.decorative finishes

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StructureIntroductionObjective

DecorativePlasteringConcreteFinishesFloorFinishesWall Finishes

Paints

MiscellaneousDecorativeFinishess-aryKey Words

FurtherReadingsAnswers to SAQs

In every building, finishes are provided as a part of the final treatment todl the surfaces ofwalls, ceilings, floors, wood work, metal work, etc., both internallyand externally. These couldbe in the formof different types of plastering, diskemper,colour washing,snowcem,painting,varnishing, flooring, wall tiles, papering, finishes to concrete surfaces ctc. These buildingfinishcs or treatments perform, two major functions:

i) They provide a pmlectivecoating to the surfaces, This helps in preservingandprotecting thematerialsused in thebuildingconstructionfromenvironmentaleffects like heat, frost, and rain water.

ii) They provide decorativefinish or treatment which adds to the aestheticappearance of the surfacesandthe building.

In this unit, our particular emphasiswill be onmoderndecorative treatments andfinishes ondifferent surfacesin a building. Any brand names mentioned in the text are only for illustrationandeducational purposes, andshouldnot bcconstruedasrecommendationforuseofanyparticularproduct/finish.Objectives

At theend of this unit you should be able to* describe decorativefinishes for differentsurfacesinabuilding* clistinguishbetween theeffecl-ivenessof differentfinishes for the same surface andchoosetliemostappropriate."

describetheprocedure for carryingoutaparticular fmishand heprecautionsre-quired tobc observed duringexecution.

7.2 DECOMTHVE PLASTERINGPlastering is the proccssof covering uneven surfacesinstructures with aplasticmaterial knownas plaster. It is alsoreferred to as"rendering"when describing the plasteringappliedto theexternalsurfaces ofwalls obnprove theirappearanceand to protectthernfromenvironmentalagencies like sun and rain. It also provides the satisfactory base for decorating the surface byapplying colour wash, distemper or paint on it.

While there areseveral typesofplasters,the most common are cementmortar,limemortaraudcement liniemortar plaster. I-Iowever,hi this unit, we shalltake about decorative finishes inPlaster.


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MiscellaneousMaterials 7.2.1 Stucco Plaster"Stucco"is the name given to aneye catching decorative plaster which is used both on interiorandexterior walls. The stucco plastered surface has anattractive appearance, which closelyresembles marble finish. Let us see how it is applied.

i) After preparing thewallsurface, the first coat of lime plaster is applied inthicknessof12mm.This is called scratch or rough coat.ii) After drying of the scratch coat, the second coat also known as finer or brown

coat of lime plaster, which is richer in lime, is applied in thickness of9mm.iii) After drying of the second coat, the finishiningcoat of thickness 3mm is

applied. This consists of a mixture offrnest h e and well powdered white stonelikemarbleor quartz.iv) Now, the fishing coat is polished properly, initially with linen bag containing

moist chalk and then with oil and chalk. The surface is finally rubbed with oilonly and finishedperfectlysmooth.

i) After preparing the surface, the first coat of composite mortar1cement:3sandmixture with 10% by weight of hydrated lime is applied on the surface upto12mm thick.

ii) When the first coat has been cured and dried, second coat of same compositionas first coat is applied in thickness of9 m .

iii) The finishing coat consisting of1cement:2 sand is now applied in thickness of3mmafter second coat has been cured and dried. In case you desire colourfinish, then colouredcement may be usedin thiscoat.

Wewillnow discuss some special and decorative external finishes for plastered surfaces.

7.2.2 ~ b u ~ hCast or Spatter-dashFinishIn this finish, the plasticmix has proportions of1cement: 1.5 sand:3 coarse aggregate and isdashed against the prepared plastered surface by using a large trowel. The surface is finishedrough by means ofawooden float.

Fig 7.1 : Roughcnst The roughcast hishisdurable,resistant to crackingandcrazingandis consideredwaterproofWet-nash Or Haruns by adding water proofing agents to the mortar. Icoloured finish is desired then suitable(Approx. 0.5 size ) colouringpigments canbe added.This fmishispreferred for buildings which aresubjected to

heavy rainfall and strong winds. This finish is shown in the Figure7.1

Flg 7.2 Pebble - Dash(Approx. 0.5 Size )

7.2.3 Pebble-dash Finish

In this type, initially a rendering coat of1:3 cement sand mortar and 12mm thickness is appliedto the surface. When this m o w is still fresh smalldrypebbles or crushed stones of size lOmmto20mmare dashed or thrownagainstit.Then thepebblesare lightlypressedand tappedintothemortarwith awooden float.

The finish obtained is similar to rough cast fmishand is effective against heavy rainfall andstrong winds. This finish is shown in the Figure7.2

7.2.4 Depter Finish

This is another variety of rough cast finish. The rendering coat is same as that for Pebble Dash.When it is still wet,pikces ofgravelor i lht of different coloursare pressedwith hand into thismortar. You canobtainbeautiful coloursand ornamental patterns in this typeoffinish.7.2.5 Sand- facedFinish

This finish is carried out in two stageslcoats. The first coat comprising 1cement :4 coarseangular river sand is applied over the surface uptoa thickness of12mmminimum. It is thenwellcured with water for7days. Now second coat of cement plaster 1:lcement and uniform sizesand is applied in thickness of8mm.When it isstill wet, sponge is applied to obtain sand facedfinish. The surface of final coat is finishedbyrubbingit with clean and washed sand usingawooden float. The resultingsurfacehasequalanduniformdensitysandgrains.It is then wateredand cured for15days. a


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7.2.6 Scrapped FinishThis type of finish is obtained by scrapping the finalcoalofplaster a few hours after scuing,bymeans of steel straight edgc,or board studded with nails or other toolslike steel combsuptoadepthof3mm.This scrapped surface is less prone to cracking and has a rough finish withexposedaggregate and texture. This Finish is shown in Fig7.3.

Decorative Finishes

Fig 7.3 : Scrnyped Finish

7.2.7 Textured or Ornamental FinishThis type offmish is obtained by use of suitable tools like combs, trowelsor special tools onfreshlylaidiinalcastofstucco plaster describedat7.2.1.Ornamentalpatter~lsareobtainedwhich look very pleasing as shown in Figure 7.4.

, (a) Fan texlure '(Approx. sire) @) Ribbed Texture

(c) Ornpmental Finish (d) Ornamental tinlsaFl g 7.4 : Textured or Ornam entnl F l d h

7.2.8 Special Materials Used in PlasteringDecorative appearance or finish is also obtained in plasteringbyuse of special materials inthefinishing coat. Let us study some ofthese now.


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MiscellaneousMnlcrials a) Distinctive finishingcan be obtained by use of saw or timber boards. This effectcan b e e d a n c e d by deliberatelyusing boardslforms of unequal ~hickness.b) Finishing may be emphasized by fixingangle fillets over the joints of boards.The fillets should bevery lightly fmed to the shuttering. When formwork is

stripped, the fillets swollen with moisture from concrete should be left in place.As they dry, theywillshrink and fall out. Pleasing effecl can also be obtainedby ~s in~ careful ly createdplanedboards together with fillet treatment. Thisfinish is shown in Figure 7.9.

c) If it is desired to hide the faint grain markings left by the planed board, then theconcretesurfaceshouldbewire brushed to remove laitance, and treatedwithany concrete paint. A plain smooth surface may be obtained by lining theformworkwith thin mctal sheet or plywood. The plywood should beresin-bonded type so as no1to be affected by moisture. Plywood should bepaintedtopreventgrainreproduction.

d) Very pleasing effect may be obtained by using linings ofwall board or hessian.Where hessian is used, it should be of a coarse texture to obtain the weavepattern. It shouldbewellstretched and be turnedover the edges of shutteringat

joints, as otherwise, concrete is liable to work up behind it. iI* e) Moulding, flutes, reeds, letteringanddecorative featuresmay be reproducedbyfutingappropriate insets in theshuttering. Plaster moulds should b e used where

high degree of finish is required or complicated designs are to be reproduced.Such moulds should be of stick and 'rog' type that is, the plaster is reinforcedwith sticks and strips of canvas. They are generally used once only and whereundercut workisbeingproduced, it canbe broken awaywithout damage toconcrete. The expense of such moulds is offset by the high degree of decorativefinish obtained thus obviating the need for any retouching of concrete. ThisFinish can be seen in Figure7.10.

Flg. 7.10 : Flnish uslng of Plaster mouid~

f) Very pleasing effect can be obtained by using textures impendedin rubber andplastic form liners.

7.3.2 Textured Concrete Finishes

Tex?ured surfaces are pleasing and eliminate smallvariations in surface texture and colour onthe form work finish surface. Several types of designs can be incorporated on the surface. Thctexturedfmishescan beobtained bythreemethods namelyTexturedfor~niners,Exposedaggregate finishesand mechanical finishes.

a) Textured Form Liners

Interesting effectson concrete can be produced by the use of textured form liners. Thevariety can range from ridging or dimplingor repetitive geometrical designs to complexmural designs. The flexible liners can be moulded to impart a variety of patterns. The

liners are generally madefrom rubbers,PVCor fiber glass and can be reused severaltimes. They canbe used both in precast and cast-in-site concretes. Specialdesigns formurals are sculptured, either insand beds or in expanded polystyrene blocks. The panelsaregenerally cast face downwards to obtaina clearer reproduction of the details ofdesign. This finish is shown in Figure7.11.


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Fig. 7.11 : l'exiured Form Lincnr Finlshes

Exposed Aggregate finishesThe colour, texture and shape of coarse aggregate can be usedadvantageouslyby expos-

ing it. This can be done by various methods. One of the methods is called"The face up

method". He r e a base of ordinary concreteis cast, screeded and trowelledflat.This sur-face is Lhen covercd unifornilywith the desired aggregate. It is then floated into the sur-face and again trowelled flat. When the initial set is about to take place, a thin layerofcement paste is carefully removed by washing the surface with alight spray ofwater.The results a re quite pleasing ifsmall aggregatevaryingfrom 10mm to 20mm are used.If the cement film is to be removedwitl~in48hours of casting, then the surface maybescrubbed with stiffbrushes andw ater or dry brushedwith a stifffibreor wire brush.Care milst be taken to see that concrete is sufficiently hard so as not to dislodgethe ag-gregate. This Finish is shown in Figure 7.12.

(4 @)Fig. 7.12 : Exposed Aggregate Finlshes


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Misccllqr~eousMaterials i) Use of Retarding AgentAnother way to achieve the objective is to apply a retarding agent to the surfaceof the concrete after trowelling.After about16hours, when the rest ofth econcrete hasset, the retardedsurfacepaste canbe brushed andwashed offeasily.A retarder can also be used as a coating on the formwork so as to retardthe concrete in contact with the formwork. It can be painted on to the formworkor a cloth impregnated with the retarder can line the formwork. You can use thisfor casting both horizontal andvertical surfaces. The horizontal casting is usedinprecast elements,where the prefabricated panels are cast face down with theretarding form at the bottom. A special facing mix may be used consisting ofaggregates possessing good colour, texture and shape, together withwhiteorcoloured cemen t.Plain concrete is then cast on top to form a n i n t e p a lpanel.However thisapproach isreplacedbytheprepacked aggregate methodinvertical casting. What kind of retarder one may use, you may ask? Well, thequantityandqualityofretarderdependson the depth ofcxposure of theaggregate, youdesire.A water-insoluble retarder isrecommended for exposureto a depth ofupto 3mm,while water soluble retarders will give greaterexposure.Generallythedepthof exposure shouldnot exceed one-thirdoftheaverage diameter ofthe aggregate to be exposed. The size of aggregate can alsobe determineddependingon the depth of texture and the distance at whichtexture should be visible. Some relevant information is given inTable1.

Table 1:Visibility Scale for Exposed Aggregate Concrete

ii) 'Acid Etchingn;Vashing

Size of Exposed Aggregate

This consists ofapplying liberal washings of hydrochloric acid solution ofapproximately one part acid to six parts of water. The acid attacks the cementand enables it to be brushed off. If the solution has no effect, it should begraduallystrengthened. Following precautionsmust be observed:

--

Distance at which Texture is Visible

- Workers must wear rubber gloves.

- When sufficient penetration hasbeen achieved the work must be waslleddown thoroughly with cleanwater to remove all traces of the acid solution.

- The surface should be treated with an alkaline solution to neutralize anytracesof acid

-This treatment must not be applied on concretc made with carbonateaggregates like limestones, dolomites and marbles.

Ti) Sand-Bedding TechniqueThis is used gainfully when large aggregates arc required to be exposed, orwhen special effects like flat-stone arrangement is required. To begin with, abed ofsandas usedinconcreteisspread, and the desired aggregate is embeddedin it to the required depth=This layer is then dampened and consolidated,and structural concrete is cast on top of i t When concretc has hardened, thecast panel is removed and excess sand is washed off its facc. This techniquepermits depth of exposure of12to 50mm of the aggregate, which is muchgreater than what is possible with retarding agents.

c) Mechanical Finishes

This method involves abrasive action and fraction processes. In abrasive action we havethe use of"Sand Blasting"for obtaining exposed aggregate by abrasing of the hardened

paste. Light sand blastingmay be used to obtain lightly roughene d surface without ex-


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Decornl ive Finishes

Fig. 7.13 : Mecbn~llcnlPinlsl~es

posing aggregate. It can also exposc 1lie aggregate lo a depth of12mm.However, byusingrubbertcmplatcstoprotcclprcdetcrmincdareasnfconcrete,veyplcasantdesignscall b c obtained by use o lsand blasting as can be scen in Figure7.13.

A bush hammer lias a series of pyramidal tecth on its facc, an dc a~ ibehand, pneumaticorelectricallyoperated.Powcaopcraledcqaaipnic~itisesscntialforlargeswfaces.

(a) Ilosh hnrtui~erin use @) Close up of bufihhammer

Fig. 7.14 Texture produced by bush hammering varticelly casl ribs.


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MlscellsneousMaterials Themaincharacteristicofbush hammering is that it not onlyremoves the outer cement film,butalso breaks some of the exposedaggregate, giving a bright, colourful and interesting facade.Very pleasing effects may be obtained by carefully selecting aggregates, which may be larger&an thoseforthe exposedaggregate finish, to produce the requiredfinish.Concrete mustbe atleast three weeks old before it is bush hammered as otherwise there is danger ofwhole pieces ofaggregate being dislodged. This finish can be seen in Figure7.14.

7.4 FLOOR FINISHESThere are a large type of floor, and floor finishes available today ranging from common to verysophisticated and decorative.Theselection of a particular floor type will depend upon severalfactors like sub floor type, suitability to receive various floorings, resistance to wear, chemicalresistance,impervioussurfacefinish,maintenance,soundinsulation,appearance,durability,smoothness and thermal insulation.While there are several types of floorings and floor finishes,we would study few special types which are now being used extensively and some of them areof recent origin in the country.

7.4.1 Terrazo Flooring

The terrazo flooring is a special type of concrete flooring in which marble chips are used asaggregates.The terrazo finish is at least lOmm thick, and comprises a mixture of desired cementlikewhiteor colouredcement, marble powder andcoarse aggregates such as choppings of

marble, pearl, glass, quartzite etc. ofselectcd colours and size grades f rom2mmto 8mm.Sometimes, large aggregate sizes are also in use. This terrazo finish is provided over theconcretebasecoarse,whichispreviouslyprepardandroughened o p o d e proper bond.Firstof all a thin coat of cement slurry is spread over the wet concrete base. This layer is then sweptwitha broom, and a layer of cement mortar 1:2,12mm thick is evenly spread immediately overit. Metal or glass dividingstrips about 30mm in depth and 1.3mm in thickness are inserted onedge in desiredpatterns. Whenthe mortar bed has sufficientlyhardened, the terrazo topping1cement:3 marble chips,6to 12mm thick (depending upon the size ofthc chips selected), in aworkablemixwithwater is applied.This topping is then rolled and compacted in bothdirections.About 85% ofthe marble chips should be exposcdover the finished surface. Aftercuring for several days, the surface is properly polished by means of a grinding machine fittedwithcarborundum stone disc. During the process of grinding, the surface is kept wet. Holes or

pores are filled with a thingrout of matching cement paste. The surface is then again cured for afew days and finally ground by grinding machine fitted with a finer carborundum stone disc.Finally the surface is washed with a week solution of soft soap in warm water. The final surfaceis very pleasing in appearance. Tlle terrazo flooring is very popular for use in banks, hotel,office buildingsand in living accommodations because of its wear-resisting properties anddecorativeappearance.Insitu terrazo canbeused forwallfinishes also.7.4.2 TiledFlooring

a) Precast terrazo tilesaremanufacturedinsquare, hexagonalandmanyothershapes and thicknesses these days. These tiles are cominonly used for flooringin residential buildings, hotels, officesandother public buildingswhere durablefloorswith pleasing appearance are required.The terrazo 'mosaic' tiles come insingle colours or in combinations. Some of them have rich variety of carpetdesigns and are called Galicha. A few designs are shown in Figure 7.15.The ground for receiving the floor is levelled, well watered and rammed, and ontlus sub grade of lime concrete usually 150mm thick is provided. Over the subgrade a thin layer of cement mortar 1:l or lime sand mortar 1:3 about 25inmthick is laid as bedding mortar for tiles. The bedding mortar is allowed to hardenfor fewhours and then neat cement slurry is spread over the surface. Now thetiles with a thin coat of cement paste applied omtheir surface are laid flat andpressed so that extra mortar comes out through the joints which is wiped clean.The joints are kept as thin as 1.5mm.After 2 to3 days, the joints are wellrubbed with a carborundum stone to levelanyslight projections above thesurface. The entire floor is then polishedwith soft carborundumstone first andwith pumice stone later. The polishing is done using a machine. Finally thesurface is washed with a weak solution of soft soap in warm water. However,these days, to obtain high adhesion strengths, polymer based hydraulicallysetting ready to use water prooftile adhesives are available which can bond thetiles by thin bed method. There is no necd to wet the tiles and tile laying output


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MOSAIC SYNTHETIC MARBLE

CRAZY MARBLE GALICIIA

is2 to3times more than the conventional method.The bed adhesive mortarthickness is 1 to 2mm only. For heavy tiles like marble, polymer based, ready to

Fig. 7.16 : Ccrnlnic Tile finishes


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Decorntlve Plnlshes

Pig. 7.17 : Murhle Asglomeraled Tlles & Finlshes

7.4.3 PVC Floorings

a) Vinyliserl TileThe PVC flooring is alsoa recent development, and has bccornevery popular as a Pfinish in all typcs of buildings. T h e P V C (polyvinyl chloride) is fabricated in thl- '.of tiles and is available in different sizes and colour shades. The overall adva-vinylised tiles is that it provides a flooring orgood com l~iercialsuitability at a,economic price. They are laid on the concrete baseusing adhesives. The floors SI. ~ l dbeprotecledagainst indentationfrompoinlloading.Heavyfi~rnitureshouldefitted

Fig. 7;18.,VLnyl Asbtstos Tlles Floor'


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MiscellaneousMaterlnk more elegant the finish as there are fewerjoints.Granite, though expensive, isverydurable,bighly scratch md chipresistant and is easy to clean and looks elegant. Granite is also known astoughest stonewithsoftest feel.It canbepolished for apermanentshearand tnirrorsmoothness.It is perfect for floorings, stairways,corridors,pavements, ornamental pillars, monuments,elevations, bath room tiling,etc."MarbleFIooring"is usedin the superior typeoffloorconstruction particularlywheresanitationandcleanlinessarerequiredasincase ofhospitals, temples, theatres, hotels, bathrooms, kitchenetc. Marble comes in different shades and has the quality ofimparting coolness to the eyes. Itcomes inslabs and nowadays in tile form also.Tajmahalis the fmestexample ofuseof marbleasa decorative and functional material.

Other stoneswhichlookbeautifulandcheap,areCuddapah,KotastonesandDholpurstones.WhileCuddapahaadKotastonesareusedinflooringinimportantareas, Dholpur stoneisusedto enhance the facade beauty of a building, and is verypopular in large hotels and even inresidential buildings. Cuddapah stonegetsstainedbyacidicsubstances.In generalthestoneused in flooring should be ideallyimpe~ousand sturdy. Machine cut andpolishedstoneshould be usedinflooring as it is easier to clean and gentler on the feet and looksmoredecorative.

7.4.9 Interlocking Concrete Block PlooringTheseconcreteblocksareinterlockmgandprovide ahighresistance to the transverseshearingforces. At the same time dismantling is easy and can be done without any damage. The concreteblocks havehighcrushingstrength,andareportable,skid proof,weather resistantanddurable.They can belaidquickly and the area can be used immediately. Their appearance is decorativeas they come in range of colours, shapes and designs. They are ideal for paving areas quicklywithminimumlabour without use ofanycementingmaterial.These type of concrete flooringblocks are shown in Fig7.19.

UNIDECOR WNI-REGULAR BRICKPAVER

Flg. : 7.19 : Concrete Flooring Blocks


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MlsccllaneousMnlerlnls 7.5.2 Plaster ofPariswa l l FinishPlaster of Paris moulded in flor al, geometricor repeatable patterns is a favourite amongwallfiiiishes. Inthi s the shapes are cast in m ouldsand f ~ e don the wall at random or in a plannedmanner to obtain decorative designs. Aplaster ofparis surface can be made to resemble or looklike a stone surface like malachite through a process called"distressing".

7.5.3 Wall Coatings

New wall coatings are now available for providing decorative finish. The wall coating isgenerally areadymixof inert fillers like marble powder, limestone, sand etc. with a polymer

binder. It canbe sprayedby spray equipment, thus eliminating the bothcration ofsitemixingwhich has to be done in case of plastering. The process of application is very fast and the coatingdries quickly. One can achieve smooth or textured finish and pigments can be mixed togeldifferent colours.The wall coating is flexible and, hence not liable to cracking. Anotheradvantage is that it can be used almost on all k i d of surfaces including concrete, painted wood,glass and metal. Even old tiles on walls canb e covercd with this finish to obtain uniformappearance. One such coating for wall and ceiling is called "Alltek". Another single coat wallcoating which is available in 100shadts and is claimed to be permanent, economical, lowmaintenance cost, beingfiingus,fire and fadeaqd, damp resistant, washable and consideredsuitable forapartments, bungalows, hospitals, lobbies, corridors, lift facias, partitions, ceilingsand stairwells, is called "Heritage".

o 7.5.4 Exterior Wall CoatingThe first impressionabout a building is made by itsexterior looks. The exterior finish serves thedual purposeof aestheticsand protection. Texturisedexlerior finishesareverypopular,andareavailable inas m anyas31shades. One such finish contains granite based aggregate fordurability and special resins to improve adhesionand prevent peeling off. It has thermo plasticcharacter and hence flexible and prevents cracking. It is also impervious to chemical andsalinecorrosion. One suchexterior Finish paint is soldunder th e name of"SandtexMatt".Another suchcoating whichisweather resistant and damp resistant is called "Heritage"surface textures.It is asingle cost mulii colour surface finishing system which is durable and washable. It has over 100shades.TheHeritagerangeconsistsofFlakes,Granules, Granite Finish andMetallic.Ernce color- flexisaspecially designed protectionand decorative coating for plaster, brickwo rkan d concretesurfaces.This coating is carbonation resistant and it has crack bridgingproperties.Normally, two coats of this areapplied on the preparedsurface,with paintingrollersor brushes. A primer coat ofPrimox250improves adhesion and scaling of the surface. Anotherwall finish is called "Spectrum",and it is a single coat application. Tliese wall finishes areclaimed to beanti-fungal, anti-graffiti, fire retardant and come in myriad designs andshapes.

7.5.5 Wall Coverings

Several types of wallpapers are available,which are used on walls and ceilings to improveaestheticvalues of the interiors ofbuildings.The three common type of papers used for paperingare:

i) Commonor pulp paper

ii) Satin Paperiii) Flock Paper

The first type is most commonly used for ordinary papering. The satin paper is maintained cleaneasily but is affected by dampeners in the walls.The third type has very good aesthetic appealbut is prone to dust. The wall papering process is as below:-

i) The wall surface to be paperedshould be rubbed down and scrapped free of dirt,oldwhitewash or colourwash or any other similar treatment.

ii) Prepare adhesive paste by mixing floor, g4ue and water. Small quantities of alumand coppersulphate aresometimesaddqdinthe paste to improve flow andtermiteproofmgpropertiesrespective~y.However,thesedaysmodernsyntheticpolymer basedadhesives are availablefor wail paper bonding and other bondingapplications. The most commonly used synthetic adhesive, whiteglue, is based

on a chemical known as vinyl acetate which is ~oly lner isedto form polyvinylacetateadhesive.Theyarenontolric,odourlessandinflan~mable.iii) The paper is coated with adhesive andspread on thewall and finished smooth

with a roller covered with flannel.Wall coverings enjoy immense popularity in the West and are gaining ground in India slowly.


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However humid climate like that in Bombay is not most conducive for wall covering, though ofcourse it can be used in air conditioned interiors as in hotels and offices. The choice of designs isvery large. Cheerful floral patterns and chickgeometricand stripes are availablebutsquiggles,gasses, mock suedes, metallics are also becoming popular. Wipeablevinyls in myriad designsare most popular and practical. One type of wallcoveriiig is called "Clarsivin".Another type ofwall paper is manufactured byM/s Bhor Industries. Plastic wall fabrics and filmsof vinyl arealso used as wall covering.7.5.6 Wall and Ceilings Boards 'Officesare a centre of life for people where they spend most of their day time. Therefore theyneed a finish on partitions walls and ceilings which is versatile, fire resistant, and soundinsulating.One such material is called Gypsum Board. It is light weight, simple to erect and isabout 25% cheaper than other materials. It can take on ninedifferent kinds of finish andis idealfor wall linings, ceilings and partitions. Its market name is"Gypboard.

Another boardis cement-wood wonder board which is claimedtobevirtuaUyincombustibleandits trade names is "Bison Panel". It is a unique combination of two most resilient buildingmaterials-cement and wood. It is ofhighstrength,fire resistant, termiteproof,weather resistantalld dimensionally stable and nou-toxic. It is easilyworkable i.e. it can be sawn, drilled, nailed~ l d s h a p e d w i t hcarpentry tools.1t can bepaiiited, laminatedor surfacecoated,Itprovidessoundand heat insulation. It is available in thickness from4 to 40mm.In addition to use as wallpanelling, it can be used ina wide range ofexteriors and interiors, like prefab houses, partitions,shutters,cupboardsetc.noth her board is called Hex-0-board.It is a high pressure, steain cured, asbestos ccmcnt boardwhich is versatile and elegant. I t is totally incombustible and fire-resistant, and ideal for highrise buildings. It can be easily cut, drilled, nailed and screwed with ordinary tools. Flex-0-boardcanbe paintedwith any paint. It can take on decorative paper or laminatedpaper.It is alsosmooth, insect andvermin proof.

A newdesigncr board which can be used for wall panelling is called"E-Board Classic", whichoffers awide range ofself embossed building boards. It combines superior attributes of cementwith stylish aesthetics and easy work ability. It is also fire retardant, termite proof, warp andcorrosion resistant. It is idcal for wall panelling, partitioning, falscceilings and cabinets.7.5.7 Natural Stone Cladding

Stone is a traditional element which has come into its own today in a newer form, of muchthinner slabs and in tile form thus making its installation much easier. Stone is sometimespainted over to highlight the texture or the colouredstone cladding can be used to provide anaestheticappearance. Stone claddingissuitable for most locations injudicious amounts only, as

Decorative Finishes

Fig. : 7.20 : Natural Stone Clrdding


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excess of it in a room could cause an overpowering and boring effect. The stone finish is verypracticalin bathrooms, kitchens, wide passagesand places which are likely to collect dirt.~raniteandmarblearelhemostpopularstonesforcladdings.~thersaresandstone,Kadappaand Dholpur stone which are machine cut and polishedwith thickness from 20mm to 87mn1.Thepicturewhich follows showspolishedgranite cladding on the Terminal building, SaharaInternational Airport Bombay.ThisFinishcan be seen in theFigure 7.20.7.5.8 Agglomerated Marble Wall Facings

Agglomeratedmarblegotdeveloped to fulfiilthe demand for new and suitable internalandexternalfacings for the buildings to provide an aesthetic qualilycombinedwith superiortechnicalperformance.Agglomeratedmarbleiscomposedofselectedqualitymarblepieceswhich are bonded together withspecial polyester resins or while cement. This material is usedLOproduce standardsize blockswhich are then cut into slabsof required thickness. Themanufactureof the standardsize block is done by usingavacuum vibromixing method 10ensurehomogeneity and highdurability.This material is strong, aesthetically appealing and can havevarying colours. Byvarying combinationsof base materials in terms of grain, size, type andnumber new colourschemes with originalvisualeffects can be generated. Some ofthesefinishes are given in Figure7.21.

Flg. 7.21 : Agglorneraled marble wall facings

Agglomeratedmarbleis ideally suited for both interior and exterior wall surfaces,When used oninternal wallsurfacesit offersunmatched elegance. Its exceptionalqualities like resistance toatmosphericagencies,freezing and thawing,anditspermanence, imparts durabilitywhen usedon externalwallsurfaces.The agglomerated marble enablesusto create exclusive walledsurfaces,which can have original shades, and personal touch of the designer,' a ndauniformitywhichcanberepeated.


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Mlscellaner~usMnleriuls c) Bituminous and Ta r PaintsThese paints contain bitumen or tar dissolvedin naptha, orpetroleum orwhitespirit.They are alkali-resistant, and havea high coveringcapacity. The paintedsurfaceprcsentsablackappearance.Thesepaintsaresuitableparticularlyforpaintingstructuralsteel and ironwork under water. The colour of this paint can be modified by adding cer-tain colouringpigments like rcdoxide. They are also used in this form for paintingextcr-nal brickworkandplasteredsurfaces.

d) Cellulose Paint

This isa

different kind ofpaintcornparedto ordinary oil paints. Thc differenceis thatthe cellulose paint hardens byevaporation of the thinner or solvent used while the ordi-nary paints harden by oxidation.

The cellulose paint is made fromcelluloidsheets,nitrocotton,photographicfilmsetc.Cellulose paints areslightly costlybut far superior than ordinary paints. They can beeasily washed and cleaned. Cellulose paintscan stand extreme degrees of heat and coldandare unaffected by hot water. They dry rapidly and possessgreater hardness, smooth-ncss and flexibility. These paints are used for painting cars, aircrafts and other surfacesrequiringsuperiorfinish.

e) Silicate PaintThis paint is produced by mixing calcinedand finelyground pure silica with resinoussubstances. In a dry state it forms very hard and durable surface. The silica paints pos-sessthe qualityof good adhesion and are used on brickwork, plaster and concrete sur-faces directly in two or three coats. NO priming coat is required, but the surface shouldbe wetted beCoreapplication ofthis paint. The painting should not be carried out in hotweather.This paint has no chemical reaction with metals and is unaffected by alkalis. 11canwithstand exlreme heat and hasgood coveringcapacity.

f) Rubber Based PaintsThis paint consists of synthetic resins dissolved in suitable solventsanci then furcdwithother pigments. It possesses several special qualities. It has excellent acid, allkali andmoistureresistance properties. It dries rapidly and has high coveringcapacity. It isno1very costlyand can be easily applied on differentsurfaces. The painted surfaces exhibituniformityin colouron drying. It offerssufficient resistance against weather elementslike rain, snowfall and hot sun.Synthetic rubberpaints are readily usedfor application over fresh and limeplastercdsur-faces.They are used as aprotective coating on concrete floors and masonrysurfaceseven when they are not dry completely.

We shall now discuss a few paints, which impart excellent decorative frnish to the sur-faces.

g) Enamel PaintThe enamel paint consists of metallic oxide like white lead or zincwhite which isgroundwith small quantity of oil and mixed with petroleum spuit containingresinousmatter insolution fom .Thus thereare four major constituentsnmely oil, petroleum,metallic oxide and resinous matter. These ~ a i n t sare availablein ready to use form inthemarket inwidevarieties.The enamel paint hascertainimportantqualities.i) I t dries slowly, but on dryingit produces averyhard, impervious, elastic,

smooth, glossy and durable film over the painted surface.

ii) This paint is flowable, and leavesnobrush marks like other paints. The enamelpainted surface is easilywashable.

iii) The enamel painted surface is not affected by hot and cold water, acid, alkalies,steam, fumes of gases, etc.

Enamel paints, with so manyqualities,areused both for internal and external surfacepainting. The appearance of glossiness of painted surface can be fu rther irnpro1:t:d hy ap-plication of a coat oftitaniumwbite in pale linseed oil on the surface before the applica-tion of the enamelpaint.

Theenamelpaintsaregenerallyusedforpainting of porches, entrance halls, decks,stair-casesandconcretesurfaces.

Some of theenamel paints are BrolacPolyurethane Enamel, Shalimar Sup erlacSyn-theticEname1, etc., among a large variety available, These paints are available in a largenumber ofshades.


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MlscellamousMaterials 2. List the commonly usedwall papers and describe thef ~ gprocedure ofwallpaper.

3. Mentionthepurposeofpainting.

4. List the types ofpaints.

7.7 MISCELLANEOUS DECORATIVEFINISHES7.7.1 Decorative Ceiling Tiles

~. There are several types of decorative ceiling tiles available. One type is made from specialqualitythree layered particleboard.It is flatpressedandboardedwithBWP-gradephenolFormaldehydeSyntheticResin.Thismaterial is ideal for making rigidandstrong decorativeceiling tiles. They are availablein embossed designs also. D

PI$. 7.23 : Dccoratlve Celllng TUesThese tilesareavailable both hrtlfandfull perforated in size of60X60cmsand 12mm thick.They are fire resistant, termite, weather andfungus proof, dimensionally stable and warp free,and provide excellent insulationagainstheatandsound.ToplineCeiling Tilesisone such type.Another type is Anchor Ceiling Tile.Similarly, there are other brands, which come indifferentarchitecturalpatterns,andarecomideredideaIforhomes,offices,showrooms,restaurants,auditoriums,airportsandfactories.Theycomeindesignslikediamond,hequered,paragon,Serrated andGothic.Theycombine beauty and safety. These tiles and finishCanbe seen inFigure7.23.


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Miscellnneous Materials 7.7.2 DecorativeCeilingFalseceilingareused inbuildiigsfor architecturalapplications.These ceilings come indifferentmaterials,andthey offer solutions for commercial design problemssomeoftheseceilings areshowinginFigure7.2.4. Recently, colour coated steel sets of false ceiling panel have entered themarket.Theycomeindifferentcolours,f ~ s h e sand patterns.

I

II' Flg, 7.24: Decoreilvt Ceiling

I \

Some such ceilings are called "Tract'and"Supersil".Another decorative ceiling consists ofaluminiumsheetsslatesPouvers.This ceiling system is suitable mainly for centrally airconditionedbuildings.7.7.3 DecorativeFilms forGlassSurfaces

Another decorativefinishwhichisbecoming popular is the decorativeadhesive coatedfh onglassinwindows, doors and on mirrors, shower partitions,acrjllicceiling, panels andshowcases.It rendersglassshatter-resistant anddiffusessunlightso as to lendsoftglow and preventdiscolouration of interiors. It isultravioletrays resistant.It reduces heavy air conditioningbills


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MlscelhneousMalcriclls7.10 FURTHER READINGS:

"QuartzReinforcedFlooring",IndianArchitect&Builder; Feb;92.Bhingarde Anil, "All In a Chart", India11Architect&Builder, May 92.The CFA Flooririg Comperldiunt forArchitectf and Specifiers, TheConslructionPress,Lancaster,London,NewYork.Indian Architect& Builder,July92.SB Rai, "AgglomeratedMarbleFor Internaland ExternalFacings",CivilEngineeringand Construction Review, August1991.Arora SP& Bindra SP "A Text book ofBuilding Cnnstrudion" Dhanpat Rai Sr Sons.SidneyMindess& J.Francis Young, Concrete, PrenticeHallInc. Englewood Cliffs,NewJersey.

Inside Outside, the Indian design magazine,17/19Dalal Street, Bombay.

7.11 ANSWERS to SAQsCheckyour Answers for all SAQswith specification.

7.decorative finishes

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