Masonry Construction Manual - Construction Details

Construction details

Part 3 . Gonstructiondetails

Contents

Preliminary remarks

Flatroof Parapetto warm deck

Masonrycontinuesto be the mostpopular in CentralEurope,espeformof construction ciallyfor housing. Withits diversearchitectural optionsand rich varietyof differenttypesof construction, masonryis justas fashionable as ever.Indeed,its goodbuildingscience propertieshaveincreasedthe vocabularyof its architectural manifestations. The following Details",illustrates the chapter,"Construction diverseapplicationsof masonry.Threedifferenttypesof wallwerechosenfor the details:

Shallowpitchedrodf Parapetto cold deck Pitchedroof Eaves Vergewithoutroofoverhang Vergewith roofoverhang Vergewith masonryparapet Junctionwithwall Chimney Floorjunction Openings Windowheadand revealswithoutshoulder Windowfittedbehindshoulder Windowwithperipheral sheetmetallining Doorheadandjambswithoutshoulder Doorheadand jambswith shoulder Doorto terrace Balconies Junctionwithterrace Plinth Stairs Specialdetails Re-entrant corner Corner Free-standing walls

204

. A single-leafrenderedwall . A partial{illcavitywall (outerleafof facing masonry, air space,insulation, innerloadbearingleaf) . A full{illcavitywall(outerleafof facing masonry) A schematicoverviewof the detailspresents the mostimportantbuildingdetailsfor the threedifferenttypesof wall.The detailsshaded greyareshownenlargedat a scaleof 1:10in the subsequent catalogue. In designing thesedetails, the primeobjecqualities tivesweredependable engineering and archiiectural claritv. g demandsalternative Energy-eff icientbuildin typesof wall construction with everbetter, Therefore, everthickerthermalinsulation. cavityinsulation in conjunction withan independentouterleaf240 mm thickwas included in the catalogueof detailsas thisformof wallconstruction is becomingincreasingly - a reliwidespread. lt provides- in masonry in termsof building ableformof construction sciencebut stillpermitsallthe optionsof facing masonryin the designof the actual masonrvskin.

layers includediffusion-tight Roofconstructions wherenecessary.In the othercasesthe details The use membranes. employdiffusion-resistant opento diffusion of roofingfeltssufficiently meansthata membrane on the insideis no longernecessary,providedthe layersof the e.g. belowthethermalinsulation, construction plasterboard, forman adequate chipboard, barrierto diffusion.However,it shouldnot be forgottenthatthe necessarydegreeof airtightnessmuststillbe guaranteed. The detailsshowndo not relateto specificconstructionprojectsbut instead,in conjunction withthe explanatory texts,are intendedto draw attention to possibleproblemzonesand illusfor the tratefeasiblesolutions.Theirsuitability mustbe respective climaticconditions case.Detailswhich checkedin eachindividual onlyvary as a resultof the differenttypesof in wallconstruction areshownschematically the overview of the details.

Overview

3.1.

Flat roof

3.2.

Parapetto warmdeck withsheetmetalcapping

Flat roof

Flat roof

Parapetto warm deck with precastconcrete coping

Parapetto warmdeck with steelsection

Single-leafrendered masonry 365mm masonry ooooo ooo oo

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Partial-fillcavity wall 115mmouterleafof facing brickwork trtr 'n'n uu ililil

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80 mm insulation 240mm innerleaf

Full-fillcavitywall 240mm outerleafof facing brickwork 135mm insulation 175mm innerleaf

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Construction details

Single-leafrendered masonry 365 mm masonry

Partial-fillcavity wall .1 15 mm outerleafof facing brickwork 55 mm air space 80 mm insulation 240mm innerleaf

Full-fillcavity wall 240mm outerleafof facing brickwork 135mm insulation 1 7 5m m i n n e rl e a f

206

Shallowpitched roof

Pitched roof

Pitchedroof

Parapetto cold deck withsheetmetalcapping

Eaves

Verge withoutroofoverhang

Overview

3.7

3.10 Pitchedroof

Pitchedroof

Pitched roof

Pitched roof

Verge with roofoverhang

Verge with masonryparapet

Junctionwith wall

Chimney

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3.9.3

207

Construction details

3.1'l Floorjunction

3.13 Openings

3.12 Openings Window head and reveals withoutshoulder

Single-leafrendered masonry 365 mm masonry

Partial-fillcavity wall 115 mm outerleafof facing brickwork 55 mm air space 80 mm insulation 240mm innerleaf

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3.11.2

Full-fillcavity wall 240mm outerleafof facing brickwork 135mm insulation 1 7 5m m i n n e rl e a f

3.11,3

208

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Windowheadand reveals withoutshoulder withrollerblind

Overview

3.14 Openings Windowfittedbehind shoulder

3.15 Openings Window withperipheral sheet metallining

3.16 Openings Doorheadandjambs withoutshoulder

3.17 Openings Doorheadandjambs withshoulder

3.17.2

209

Construction details

3.18 Openings

3.2O Junction with terrace

3.19 Balconies

Doorto terrace

Outeredge

Single-leafrendered masonry 365 mm masonry

Partial-fillcavity wall 115mm outerleafof facing brickwork 55 mm airspace 80 mm insulation 240mm innerieaf oooooooooo

3.19.2

Full-fillcavity wall 240mm outerleafof facing brickwork 135mm insulation 1 7 5m m i n n e rl e a f

3.19,3

210

Overview

3.22 Stairs

3.2'l Plinth

lnternalstairs Entrance to building Stairsto basement

Masonrybasement Junctionwith plinth

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3.23 Special details corner Re-entrant Corner walls Free-standing

Construction details

Flat roof Parapetto warmdeck 3.1.2 Parapetwithsheetmetal.capping on furin-leaf masonry 3.2.2 Parapetwithstonecopingon twin-leaf masonry 3.3.1 Parapetwithsteelsectionon single-leaf masonry 3.3.2 Parapetwith steelsectionon twin-leaf masonry

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The mostcommonfinishto the top of a masonry wallis the cappingof sheetmetal- copper, titanium-zinc or galvanized steel.Thisis usually fittedovera suitablysizedand shapedtimber section,whichshouldbe fixedonlyto the loadbearinginnerleafand may nottransfer any loadto the outerleafof facingbrickwork, Thecappingshouldbe designedwitha fall towardsthe roofsurface.In architectural terms it is primarily the heightof thevisiblefrontlipof the cappingwhichis relevant, as thisformsthe upperboundaryof thefacade.lt is alsopossibleto providea weltededgeat thispoint, althoughthis doesdeviatefromthe stipulations of the DINstandard. J.t.z

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Finishingthe top of a wallwith a prefabricated copingcreatesa distinctboundary,oftenof a d ifferentcolour.Prefabricated elementsoffer diversearchitectural optionsin termsof shape and material- froma simpleprecastconcrete copingto dressednaturalstone. Whenprovidinga prefabricated copingto a twin-leafwall,it mustbe ensuredthat it is fixed onlyto the loadbearing 240mm wall;it mustbe ableto slidewhereit bearson the outerleaf.lt is advisable for the copingto havea fallto the inside.Theexpansion lointsbetweenthe individualcopingelements mustbe designedand carefullybuiltso that no watercan penetrate throughto the masonry, A steppedjointor a dampproofcoursebeneaththe copingis advisable. To reducethe thermalbridgeeffect,it is recommendedto use masonryunitswith a low grossdensity(thermal conductivity) for buildinn

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Pleasereferto "Part2 . Fundamentals" for detailsof the ringbeam.

212

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Flatroof

Theinclusion of a steelsectionaddsa special emphasisto the edge of a flat roofon a masonry building. Thetop of thewallis highlighted and,withan appropriate choiceof colour,can contrastwiththe wall below.However,this detailis notwithoutits problems. A steelsectioncan be fixed directlyto the top of a single-leaf, renderedmasonrywall,However,it mustbe ensuredthatthe steelsection jointsandthatthe fixings includesexpansion can accommodate the movement.The movementjointbetweena steelsectionand a renderingstop bead mustbe sealedwith a permanentlyelasticcompoundto preventmoisturefrompenetrating throughto the masonry. It is essentialto providea coveringto the steel sectionto stopwaterenteringthe expansion jolnt,The detailproposedherewith UV-resistantsheetingand a clampingbar fittedto the steelsectionolacesoarticular demandson the sealing.Greatcare mustbe takento ensure thatthe connection to the clampingbar is properlyexecuted. lf the parapeton a buildingemploying twin-leaf (withfacingbrickwork)is to wallconstruction be terminatedwith a steelsection,thenthe detailmustbe carefully adaptedto suit(3.3.2). First,caremustbe takento ensurethatthe fixingof the steelsectionto the loadbearing leaf permitsadjustment(elongatedhole)and that the sectioncan accommodateexpansion. Theremustbe no directconnectionwiththe outerleaf.Thisjointmustbe watertight,i.e.a dampproofcoursemustbe carefullybonded to the top of the outerleafand the steelsection mustbe ableto slideon this.Thesteelsection mustbe coveredas describedfor detail3.3,1. lnsteadof UV-resistant sheeting,an additional sheetmetalcappingcan be used,butthisis a considerably moreelaborateand costlydetail (see"Builtexamplesin detail",example'12).

1 2 3 4 5 6 7 8 I .10 11 12 13 14 15 16 17

Loadbearingmasonry Facingbrickwork Air space Walltie Rendering Thermalinsulation Reinforcedconcreteslab Diffusiontightmembrane Roofingfelt Stonechippings Sheetmetalcapping Profiledtimbersection Steelsection F o i ls l i pj o i n t Uv-resistantroofing felt C l a m p i n gb a r Ring beam,or ring beam reinforcement

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3.3.1

3.3.2

213

Construction details

Shallowpitched roof Parapetto cold deck 3.4.2 Parapetto cold deck on partial-fill cavitywall 3.4.3 Parapetto cold deckon full-fill cavitywall

outerleafinthe Terminating a non-loadbearing formof a parapetto a cold deck requiresproof visionto be madefor adequateventilation boththe outerleafand the roofconStruction. However,it shouldbe ensuredthatthe lastwall tie for the outerleafis fixedto the loadbearing structureas nearas possibleto the top edge of the outerleaf.The detailshownhereaoplies to sectionsof roofwhichfall onlya shotldistance.lf the parapetneedsto be higher,thenit to shouldbe builtas a twin-leafconstruction anchorthe outerleafproperly,

3.4.2

The parapetto a full-fillcavitywall is shownin detail3.4.2.In this case it is not necessaryio stabilizethe outerleaf.The requiredcrosssectionfor ventilation of the cold deck dependson the pitchof the roof.The roofcovseams eringof sheetmetalwith double-welted is possiblefor a pitch> 7'. The metalroofcoveringis givenmoreelaboratetreatmenthereto providebetterprotectionagainstdrivingsnow.

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3.4.3

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Thermalinsulation Reinforcedconcreteslab membrane Diffusion-tight Roofingfelt Sheetmetalcapping

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Ring beam, or ring beam reinforcement Timberboardingof cold deck Roofcoveringof metalsheetingwith standingseams Rafter Gutter Rooftiles HooflngTert,open to ornusron Wall plate (eavespurlin) rmoer ooarorng Roofingfelt, diffusion-resistant Tilingbattens

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Pitchedroof

Pitchedroof - eaves masonry 3.5.1 Eavesdetailfor single-leaf masonrv 3.5.2 Eavesdetailfor twin-leaf

Theeavesdetailfor a single-leaf, rendered masonrywall makesuse of facingbrickworkto concealthe ring beamand wall plate.An overhangingroofr'equires the rendering to continue up to the top edge of the rafters.Witha parapetto the gablewall(seedetails3,8.1and 3.8.3),the vergeguttershoulddischargeinto the eavesgutter. Onthe insideit mustbe ensuredthatthereis an airtightconnectionbetweenthe diffusionresistantroofingfelt and the masonry.The exampleshownhereemploysa clampingbar.

Thewall plateof the roofconstructionin detail 3.5.2is placedon the outsideedgeof the loadbearing leaf.Masonryunitsare laidon top of the ring beamto concealthe wall plateand providea consistentsubstratefor the plaster, Thereader'sattentionis drawnto the airtight connectionbetweenthe diffusion-resistant roofingfelt and the masonry(tuckedintothe plaster).The remainingcross-section of the rafterabovethe outerleafmustbe sufficientfor fixingthetimberboarding. Theouterleafis ventilated opening at the eaves.Theventilation mustincludea screento protectagainstinsects. Witha parapetto the gablewall (seedetails 3.8.1and 3.8.3),the vergeguttershoulddischargeintothe eavesgutter. As the outerleafformsthe actualweatherorotection,the roofdoes not needto overhangthe wail,

215

Construction details

Pitched roof - verge masonry withrooftile 3.6.1 Single-leaf beddedin mortar 3.6.2 Partial-fill cavitywallwithvergetile 3.6.3 FullJillcavitywallwithmetaltrim masonry withbargeboard 3.7.1 Single-leaf and roofoverhang

is takenright Thedetailin whichthe rendering of a rooftilebeddedin up to the underside mortarhas becomelesscommon.However,it stillremainsa typicalmasonrydetailand merein ly requiresa good standardof workmanship orderto be successful.lt is importantthatthe rooftileat the edgeis solidlybeddedin mortar (mortargroup ll) and thatthe roofingfelt is fixedto this.On the outside,the individual masonryunitsmustbe properlyjointedwith moharin orderto providea solidsubstratefor therendering. buildings Detail3.6.1is suitablefor low-rise thatdo notrequirea ringbeam. 3.6.1

The useof a vergetile permitsthe creationof an almostflushjunctionwiththistwin-leaf masonrywail. A numberof variationsmay be employedfor the top courseof the outerleaf(comparedetail 3.8.3).lf the topmostcourseof masonryunits is to be cut off at an angleto matchthe pitchof the roof,this can be partlyconcealedby the for the outer vergetile. However,ventilation Thelasttiling leafmuststillbe guaranteed. battencan be fixedto the boardingcantilevering beyondthe lastrafter.Thisdetailcan also renbe usedin a similarwayfor single-leaf, deredmasonrywalls.

3.6.2

216

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Pitchedroof

A foldedmetalorofilecreatesa neatterminationto the edge of a tiled roofas it conceals the edgesof the rooftiles.The metalprofile actsas a sortof "mini-gutter" and slipsunder the lastrow of tiles.lt alsoconcealsthe top courseof facingbrickedgeof the uppermost work,which is cut to matchthe pitchof the roof. Themetalprofilemustincludea drip positionedclearof the face of the masonry. As it acts as a gutter,the metalprofilemustbe ableto dischargeintothe eavesgutter.

3.6.3

Themostcommonvergedetailwith a timber bargeboardcan be usedwith differentlengths of roofoverhang.lf the overhangis large,then withtail a robustsupportingconstruction beamsis calledfor. Thesoffitboard(s)can be fixedto battens attachedto the purlinsand/ortail beams.But theseare not installeduntilafterthe rendering is complete. Detail3.7,1is suitablefor low-rise buildings thatdo notrequirea ringbeam.

1 2 3 4 5 6 8 11 17 23 25 26 28 29 30 31 81

Loadbearingmasonry Facingbrickwerk Air space Walltie Rendering Thermalinsulation Diffusion{ightmembrane Sheetmetalcapping Ring beam,or ring beam reinforcement Rafter Rooftiles Roofingfelt,open to diffusion Timberboarding Roofingfelt,diffusion-resistant Tilingbattens C l a m p i n gb a r Bargeboard

3.7.1

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Construction details

Pitched roof - verge masonrywithmasonry 3.8.1 Single-leaf parapetand sheetmetalcapplng 3.8,3 Twin-leafmasonrywith masonryparapet

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The masonryparapetwith internalsheetmetal :| gutteris a well-established means architectural for achievinga plainedge to the roof.Thetop I l witha of the renderedoaraoetcan be finished I sheetmetalcappingor with precastconcrete natural stone copings. or Themasonryparapetshouldbe at least175mm thick. j The metalgutterbehindthe masonryparapet mustbe ableto dischargeintothe eavesgutter : ( s e ed e t a i3l . 5 . 1 ) .

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Finishing thetop of thewallwitha brick-onedgeor soldiercoursecan be accomplished onlywith an outerleafof facingmasonry 24Omm thick.ln this casethe coursesof brickwork belowthe soldiercourseshouldbe cut back so thatthe metaldrip belowthe soldier courseoverhangsthe internalsheetmetalgutter. No furtherflashingsare necessary,providedthe work is carriedoutto a good stanand all jointsarefully dard of workmanship filledwith mortar(if necessarywithwaterrepellentmortar).lt is alwaysthe bricksbelow the brick-on-edge or soldiercoursewhichare cut to matchthe pitchof the roof.

3.8.3 218

Pitchedroof

Pitchedroof - junction with wall 3.9,1 Junctionwithsingle-leaf masonrywall 3.9.2 Junctionwithtwin-leaf masonrvwall

junctiondetails Details 3.9,1and 3.9.2illustrate for buildings withdifferent numbersof storeys, or whichare offsetwith respectto eachother. Greatcaremustalwaysbe exercisedat any junction. wall-roof Thepositionof the edgetiles mustbe coordinatedwiththat of the tilesat the eaves.The startof the gutterand its flashing shouldthe alignedwiththe end of thewallfor a facadeof varyingheight.On a renderedwall, the guttermustterminateat the baseof the rendering, Therendering shouldbe isolated fromthe gutterby meansof a stop bead and nearthe junctionwiththe roofshouldbe of a typesuitablefor useon groundlevelplinths (mortar groupll). Thewallconstruction shouldbe chosensuch thatthe continuousslotfor the gutterdoes not impairthe structural stability of thewall.

3.9.1

In detail3.9,2the outerleafof facingbrickwork is supported on a continuous bracket.ln this casethe facingbrickworkcan followthe pitch of the roofexactly.lt is recommended to constructthe basecourseas a brick-on-edge or one-brickcourseand to cut the bricksof the nextcourseto matchthe pitchof the roof.This recommendation alsoapoliesto detail3.9.3 (seep. 207).In thatcasethe lowerjunctionbehindthe quttercouldalsobe castin concrete.

1 2 4 5 6 7 8 11 12 16 17 23 24 25 26 28 29 30 31 32 33

Loadbearingmasonry Facingbrickwork Walltie Rendering Thermalinsulation Reinforcedconcreteslab Diffusion-tight membrane Sheetmetalcapping Profiledtimbersection C l a m p i n gb a r Ring beam,or ring beam reinforcement Rafter Gutter Rooftiles Roofingfelt,open to diffusion Timberboarding Roofingfelt, diffusion-resistant Tilingbattens C l a m p i n gb a r Metaldrip Steelangle bracket

3.9.2

219

Construction details

Pitchedroof - chimney 3.10.1Top of chimneywithmetalflashings 3.10.2 Rooftilesbeddedin mortar

passingthroughpitchedroofsmust Chimneys be flashedto preventingressof waterintothe roofspace.ldeally,chimneysshouldbe positionedto passthroughthe ridgein orderto avoidformingan acuteangleon oneside.This preferred detailis shownin 3.10.1. Thechimclayfluelining,insulation neywithrefractory and flue blockspassesbetweentrimmers incorooratedin the timberroofconstruction. withcorbal Theflueblocksarealsoavailable bricksfor the facingbrickwork,whichmeans thatthe facingbrickworkonly needsto continuedownto just belowthe trimmers.The metalflashingsand roofingfelt are easierto attachto the facingbrickworkwhenthe correspondingcoursesarecut backapprox.3040 mm.Theroofingfeltand metalflashings withdripabovecan be neatlyfixedand sealed A prerecessin the masonry. in the resulting cast concretecap protectsthe top of the chimney. lf thetop of the chimneyis to havefacing brickwork240mm thick,the rooftilescan be beddedin mortarin a recesson all sides,proallow.A fibre-reinvidedthe climaticconditions The240mm forcedmortaris recommended. facingbrickworkcan then be easilylaidon the 115mm masonrybelowowingto the bondlaid in a ringaroundthe chimney.

3,10.2

220

Floorjunction

Floorjunction 3.11.1Junctionbetweenreinforced concrete floorand single-leaf masonry 3.11.2Junctionbetweentimberjoistfloorand partial-fill cavitywall 3.11.3Junctionbetweenreinforced concrete floorandfull-fillcavitywall

Allfloorjunctionsshouldbe constructedin sucha way that an adequatethermalbreakis assured. ln the caseof single-leaf, rendered (3.11.1), the closingbricksealingthe masonry edgeof thefloorslabshouldalwaysbe made fromthe samematerialas the restof the wall. Thiscreatesa consistentsubstratefor the rendering.A stripof compressiblematerialat the insideedge of the floorsupportprotectsthe cornerof the topmostcourseof masonryunits belowtheflooragainstexcessive bearing pressure.

3.11.1

Theinsulation in the partial-fill cavitywall (3.11.2) automatically createsthe necessary thermalbreak.Thisdetailalsoapolieswhen usingfacingmasonryfor the inner,loadbearingleafas well. A timberfloorrequiresthe timberjoiststo bear onthe masonryviaa separating membrane. ln addition, air bricksmustbe builtintothewall adjacent the endsof thetimberjoists.

3.11.2

.l 2 3 4 5 6 7 I 17 25 26 28 29 30 31 32 34 35 36 38 39 40 41 42 43

Loadbearingmasonry Facingbrickwork Air space Walltie Rendering Thermalinsulation Reinforcedconcretesiab Diffusion{ightmembrane Ring beam,or ring beam reinforcement Rooftiles Roofingfelt,open to diffusion Timberboarding Roofingfelt, diffusion-resistant Tilingbattens C l a m p i n gb a r Metaldrip Refracloryclay flue lining Flueblock Trimmer Precastconcretechimneycap lmpactsound insulation Floatingscreed Compressibleplasticstrip Timberfloorjoist A i rb r i c k

3.11.3

Construction details

Openings Windowheadand revealswithoutshoulder 3.12,1Linteloverwindowin single-leaf masonry 3.12,2Linteloverwindowin partial{illcavity wall,withlouvreblind 3,12,3Linteloverwindowin fullJillcavitywall cavity 3.13.2Linteloverwindowin partial-fill wall,withrollerblindbox

It is possibleto installwindowswithouta step or shoulderin theopening,butspecialattena goodsealto tionshouldbe paidto achieving the peripheraljointbetweenwindowframeand lintelsare structure.Variousprefabricated All suppliers. frombuildingmaterials available of adequate the detailsrequirethe inclusion Detail3.12.1showschannel thermalinsulation. concreteanda blocksfilledwith(reinforced) Thechannelblocksmustbe layerof insulation, madefromaeratedclay.Windowdetailswithwillbecomeincreastngly out stepor shoulder problematic regulaas thethermalinsulation further. tionsaretightened 3.12.1

enablesa sunTwin-leaf masonry(3.12,2) shade(inthiscasea louvreblind)to be incorporatedin the cavitybetweenloadbearing eaf and facingbrickwork.Caremustbe taken to ensurethatthe reinforcedconcretelintelis shouldbe insulated; the insulation adequately protectedby a sheetmetalcover,The operatng mechanism for the blindshouldcertainly be motorizedwiththistype of detail.Thefacing brickwork outerleafcan be supportedby means of a camberedarchfor spansup to 2 m; larger spansrequirethe useof steelsections. 1 2 3 4 5 6 7

Loadbearingmasonry Facingbrickwork Air space Walltie Rendering Thermalinsulation Reinforcedconcreteslab

]lffil'."*. 47 Shallowlintel 48 Precastconcretelintel 49 Prefabricatedlintel

3.12.2

222

51 Woodenlining 52 Rollerblindwith box 53 Windowwith woodenframe

Openings

A windowdetailwithoutstepor shoulderin a full-fill cavitywall(3.12.3) is bestachievedby positioning thewindowin the planeof the insulation.A prefabricated shallowlintelcan be usedas the lintelsuppofting the innerleaf. Specialattentionmustbe givento achievinga goodjunctionwiththe insulationat the frame. Thesolutionillustratedherepresupposesthat afterinstallingthe subframe,the gap between the cavityinsulationand the windowframeis filledwithinsulation (polyurethane foam)and profiled theopeningclosedwitha continuous strip.Thewindowrevealis clad with plasterboard. J.

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Therollerblindindustryprovidesboxelements whichcomplywithallthethermalinsulation requirements. Forsingle-leaf masonry thereis a rollerblind boxwith a renderingsupportalongits outer edge.Rollerblindboxesareavailable for all thecommonwallthicknesses. Intwin-leaf masonrythe rollerblindbox should be positionedbehindthe outerleafof facing brickwork. The detailshownhereassumesa concretelintel leftexposed,whichbearson the masonry on bothsidesof theopening. Theouterleafhasto be ventilatedabovethe rollerblindbox.A damp proofcoursemustbe providedat the baseof the cavity.

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223

Construction details

Openings Windowfittedbehindshoulder 3 . 1 4 . 1S i n g l e - l em a fa s o n r y masonry 3.14.2 Twin-leaf

Windowsfittedbehinda stepor shouldercan Thejoints be sealedeasierand morereliably. to be sealedcan be hiddenand arenotvisible fromthe outside.Thesubframemayneedto be widthof frame suitablyenlargedif an identical on all sidesis desiredon theoutsideface, shownin detail3.14.1 The lintelarrangement mayemploya shallowlintel,providedthespan is nottoo large.lt is necessaryto ensureadeand quateinsulationbetweenthe lintel/masonry the concretelintelon the insideface.Thewood finishto the windowrevealshownin thisdetail on the insideof coversthethermalinsulation windowsill,in this thewindow.Theexternal caseof sheetmetal,couldalsobe madeof precastconcreteor naturalstone.

3,14.1

Detailat end of sheet metaiwindowsill

thewinwall(3.14.2), masonry Fora twin-leaf to detail3.14.1.lf the similarly dow is installed openingis nottoowide,thena camberedarch may be usedto supportthe outerleaf;spans supportin theformof > 2 m requireadditional (openperpends)to steelsections.Ventilation the outerleafmustbe providedabovethe bricksof the arch. Thewindowsillin detail3.14.2is shownas a precastconcreteelement.However,a brickon-edgecoursecouldbe usedinstead. Detailat end of precastconcrete windowsill

3.14.2

224

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Openings

Openings Windowwithperipheral sheetmetallining 3 . 1 5 . 1S h e e m t e t a l i n i n gi n s i n g l e - l e a f masonryfor windowfittedin frontof shoulder masonry 3.15.2Sheetmetalliningin twin-leaf for windowopeningswithoutshoulder

Windowsopeningoutwardsor at leastfittedon theoutsidearecommonand indeedadvisable in northernEurope.However,adequateprotectionagainstdrivingrainmustbe guaranteed, for the detailat the headof the especially sheet frame.Detail3.15.1showsa peripheral metallining,whichat the sametimefunctions masonrycare asthewindowsill.In single-leaf mustbe takento ensurethatthe windowis positioned in the planeof the insulation behind theouterlintel.lt is importantto providea carefullydetailedpermanently elasticjoint,ina stop bead,at the junction corporating rendering and sheetmetallining, between

3.15.1

masonry Thesheetmetalliningin a twin-leaf as in wall(3.15.2) fulfilsthe samerequirements detail3.15.1.Detail3.15.2showsan arrangementwithouta steoor shoulderin thewindow opening. Onceagain,the sheetmetallining alsoacts as the windowsill,projectinga sufficientdistancebeyondthefaceofthe outer leaf.

1 2 3 4 5 6 7 39 40 41 42 43 44 46 47 51 53 54

Loadbearingmasonry Facingbrickwork Air space Walltie Rendering Thermalinsulation Reinforcedconcreteslab lmpactsound insulation Floatingscreed Compressibleplasticstrip Timberfloorjoist Air brick Open perpend Masonrylintel Shallowlintel Woodenlining Windowwith woodenframe S h e e tm e t a l i n i n g

3.15.2

225

Construction details

Openings Doors 3.16.2 Dooropeningwithoutshoulderin twin-leafmasonry 3.17.1 Doorfittedin frontof shoulderin cinnla-laaf ,m,a,c-n,n- ,, r y 3.17,2 Doorfittedbehindshoulder in twin-leaf masonry 3.18.2 Openingin twin-leaf masonry for door to terrace

Dooropeningswithouta shoulderaresubject to similarconditions to windowopenings without a shoulder. Thedooris bestpositioned flushwiththe outsidefaceof the loadbearing leafin orderto providea neatjunctionwiththe floor.The edge of the floorconstruction is finishedwith a steelsection,whichalsofunctions as the weatherbar at the bottomof the door. The brick-on-edge courseformingthe threshold requiresitsownsupport.Theinsulation is coveredby a woodenliningfixedon the outsideto the sidesandtop of the opening. A camberedmasonryarch may be usedas the (open lintelfor normaldoorwidths.Ventilation perpends) for theouterleafis requiredabove thearch.The damo oroofcourseabovethe

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A doorfittedin frontof a shoulder(3.17.1) requirescarefuldetailingto provideprotection againstrain,especially at the headof the door (asfor details3.15.1and 3,15,2), Theperipheral sheetmetalliningprovidesthe necessary protection, whileactingas threshold and weatherbar.Therefore, thissheetmetalshould be thickenoughto withstand beingwalked upon. In twin-leaf masonrythe sheetmetallining shouldbe seoaratedfromthe outerleaf.This meansthat a gap can be formedto permit ventilation of the outerleaf.

3.17.1 226

Openings

1 2 3 4 5 6 7 14 17 19 39 40 41 42 43 44 46 47 49 51 54 55 56 57 6a

Loadbearingmasonry Facingbrickwork Air space Walltie Rendering Thermalinsulation Reinforcedconcreteslab Foilslip joint Ring beam,or ring beam reinforcement Precastconcretecapping lmpact sound insulation Floatingscreed Compressibleplasticstrip Timberfloorjoist Air brick Open perpend Masonrylintel Shallowlintel Prefabricatedlintel Woodenlining Sheetmetallining Wooden door with weather bar Woodendoor openingoutwards Steel section as weather bar Dcrrina

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60 Glazeddoor with woodenframe 64 Drainagechannelwith grating

Detail3.17.2showsa masonryarchlintel 240mm thick.The masonryat the sidesof the openingremainsexposed.The doorframeis positioned behindthejambsandthe lintel.In thisdetailcaremustbe takento ensurethat the lintelis adequatelyinsulatedand that a dampproofcourseis incorporated.

3.17.2

Doorsleadingto outsideterracesoftenincorporatesteps.However,detail3.'18.2showsan arrangement wherethe outsideterraceis at the samelevelas thefloorinsidethe building.The flooris steppedat this point.This structural detailshowsonlythe formof the transitionat theopening, Theouterleafof the twin-leafwall is carriedon a continuousbracketabovethe insulationon top of the concreteslab supportingthe terrace. Thetransitionfromthe dooropeningto the terraceincludesa drainagechannelcovered to the drainage by a grating;thisis connected sysrem. renderedmasonry,as shown Slngle-leaf, in detail3.18.1 schematically , p. 210,may be builtdirectlyon the concreteslab. fhe 24Omm outerleafof a full-fillcavitywall is alsosupportedon a continuousbracket(see detail3.18p . 3. 2 , 10).

3.18.2 227

Construction details

Balconies 3.19.1 Continuous balconyf loorslab 3.19.2Balconyfloorslabwiththermalbreak

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3 . 19 . 1a

3.19.1b 228

Balconies whoseloadbearing is construction integral withthefloorslab insidethe building arealwaysa problem.In buildingscience termsit is betterto providethe balconyconstructionas an independentitemln frontof the externalwall. However, in the caseof single-leaf masonry, the floorconstruction oftencontinuesthrough thewallto the outside.lf thisis done,thenthe floorslabinsidemustbe adequately insulated ( 3 . 1 9 . 1 aA) .s u f f i c i e n t w i d(tm 0 m )o f h i n . 5 Om insulation mustbe providedacrossthefull widthof the slabwhereit passesthroughthe wallin orderto reducethermalbridgelosses. It shouldbe noted,however,thatthis causes the surfacetemperatures at the junction betweenfloorand wallto drop by about2 K (2'C). Thedetailcan be substantially improvedby extendingthe thermalinsulation 20 mm intothe externalmasonry.Similarpositive effectscan be obtainedby placinga strip in of insulation approx.100mm widevertically the masonrybeneaththe floorslab. A slipjointshouldbe providedbetweenfloor slab and masonryto allowfor the differential deformation. Openings(3.19.1b) shouldbe treatedsimilarly. ln doingso,the outerlintelshouldalsobe of masonryin orderto achievea consistentsubThislintelmustbe stratefor the rendering, properlyinsulated. A smallstepfrominsideto outsideis unavoidable in thisdetail;elaborate measures arerequiredto avoidsucha step (by way of differentfloorslabthicknesses). At the sidesof theopening,the dampproofmembranebelowthe balconyfloorfinishmust extendup the wall as far as the bottomedgeof the rendering. Thedampproofmembrane is thencoveredwith a plinthof the samematerial as the balconyfloorfinish

1

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Balconies

A betterdetailfor the balconyfloorjunctionis onewithan intendedthermalbreak(3.'19.2a). Oneof the advantagesof thistype of constructionis thatthe balconycan be formedas a prefabricated unitwith an integralsurfacefinish.lt is usefulto matchthe thicknessof the balconyfloorslabto the slzeof the masonry unitsin the caseof twin-leafmasonry. Theouterleafshouldbe supportedon a continuousbracketand shouldnot beardirectlyon thebalcony.Likewise, thereshouldbe a compressiblejointbetweenthe top courseof of bricksbelowthe balconyandthe underside thebalconyfloorslab,At an opening(3.19.2b) the masonrylintelshouldalso be separated fromthe balcony.Here,the bricksare carried on a steelsection,which is supportedat the sidesof the opening. It is advisableto positionthe windowin the planeof the insulation in orderto avoidcold shownin bridges. Thesheetmetalthreshold detail3.19.2bshouldbe madefromhofdip galvanised steelof adequatethickness(4mm). Theremustbe a good seal belowthisthreshold,connectingbalconyfloorslabto bottom railof doorframe. Thedetailshownherehas a considerable differencein levelbetweeninsideand outside and is thereforenot suitablefor disabled persons.

3.19.2a

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Loadbearingmasonry Facingbrickwork Air space Walltie Rendering Thermalinsulation Reinforcedconcreteslab Foilslip joint 1 7 Ring beam,or ring beam reinforcement qtaal.n^la hr..L6t 33 39 lmpactsound insulation 40 Floatingscreed 4 1 Compressibleplasticstrip 44 Open perpend 59 Reinforcedconcretebalconyfloorslab 60 Glazeddoor with woodenframe ol Balconyfloorfinish 62 Thermal insulationincorporated in formwork with thermalbreak 63 Reinforcement, 2 3 4 5 6 7 -t4

3.19.2b 229

Construction details

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Junction with terrace Outeredge of terrace

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3.20.2 Masonryparapetabovepartial-fill cavitywall fixedto full-fill cavitywall 3,20,3Balustrade

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Theterraceedgedetailshownin 3.20.3calls for a firm bond betweenthe edge of the waterproofsheetingwhereit joinsthe masonryand the too of the outerleafabovethe levelof the concreteslab supportingthe terrace.Care mustbe takento guaranteethatthe paving slabsformingthe floorof the terraceand the slabson top of the outerleaf- whichmustbe securelyfixed- finishat the samelevel.

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3.20.3

230

The detailat the outeredge of a terracesupportedon twin-leafmasonrycan be the same as thatfor a flat roofparapet.DeIail3,20.2 showsa masonrywall (i.e,parapet)formingthe boundaryto the terracebecauseit not possible to fix a balustradeto the facingbrickworkwhichis shownin detail3.20.3.Themasonry parapetshouldbe at least 175mm thick- 240mm is better.Thetop can be finishedwith a precastconcreteor natural stonecoping,or a soldiercourse(seedetail jointshouldbe 3.8.3,p. 218).A compressible incorporatedbetweenthe masonryparapet Thisjoint- a "preandthe facingbrickwork. - shouldbe point" determined breaking elasticcompound. sealedwitha permanently lf, for architectural reasons,sucha specialjoint to buildthereis no alternative is notdesirable, ing the entireparapetin twin-leafmasonry (similar to detail3.2.2,p. 212). Adequateinsulationmustbe incorporated betweenthe edge of the floorslab and the outerleaf.Openperpendsareincludedbelow thisinsulation to ensureventilation. Thewaterproofsheetingmustbe extendedup the side of the oarapetto a levelat least 150 mm abovethe waterrun-offlayer(inthis The peripheral metalsheetwith casegravel). itsfixingand the metaldripcouldbe incorpo- but at highratedsomewhatmoreattractively er cost- by cuttingout a recessin the masonry similarto detail3.8.3.

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Junctionwithterrace' Plinth

Plinth

3.21.1 Masonrybasement 3.21.2 Plinthdetailfor twin-leafmasonry

In principle, masonrybasements mustcomply withthe protectivemeasuresfor non-pressurizedwaier- a situationwhichoccursin most projects- as laid down in DIN construction 18195part5. Thisis accomplished by using bondedwaterprooflayersof bitumenor plastic sheeting or thickbitumencoats(see"Parl2. Fundamentals"). The horizontallayerof waterproofingmustbe properlyjoinedto the vertical layer.In orderto provideextraprotection,a secondwaterprooflayercan be incorporated horizontally abovethe secondcourseof masonry.Onlyrenderingmadefrom pure cementmortarof mortargroupll may be used in contactwiththe groundand on the waterprooflayers.Thisrenderingshouldextendat least150mm abovegroundlevel.The limecementmortarrenderingabovethis shouldbe separatedby.aslit cut with a trowel,ln twinleafwall construction the waterprooflayer shouldextendoverthe foundationand as far as the top ofthe secondcourseof masonry. Theouterleafcan then be builton the foundation.The basecourseof the outerleafmust includeopenperpendsto allowmojstureto drainaway.Ventilation of the outerleafis guaranteedby way of open perpendsin the third courseabovegroundlevel;a horizontaldamp proofcourseshouldbe includedbelowthe nnon

1 2 3 4 5 6 7 8 I 10 13 14 17 58 65 66 67 68 69 70 71 73

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Loadbearingmasonry Facingbrickwork Air space Walltie Rendering Thermalinsulation Reinforcedconcreteslab Diffusion{ightmembrane Roofingfelt Stonechippings Steelsection Foilslip joint Ring beam,or ring beam reinforcement Pavingto terrace Waterproofing Protectivemat Horizontaldamp proof course/membrane Cementmortarrendering Lime-cementmortarrendering Concavefillet Concretefoundation Reinforcedconcretegroundslab

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3.21.2 231

Construction details

Stairs stairs 3.22.1 Internal to building 3.22.2Stairsat entrance 3.22.3Stairsto basement

3.22.1

Masonrystairsinsidebuildingsmaybe conof masonstructedusingvariouscombinations ry unitformatsdependingon the pitch. can construction ln principle, the supporting makeuseof loadbearingmasonrywallswith segmentalarches,precastconcreteelements or reinforcedconcretestairs.The stairtreads arethenplacedon this.Detail3.22.1shows treadsformedfrom DF unitslaid horizontallv and alsoon edge. Thisexampleshowsprecastconcretesteps withoutsoundinsulawhichare incorporated tion at the ends.To satisfysoundinsulation to usea requirements, it is recommended continuousreinforcedconcretestairflightwith at the supports. soundinsulation

as Masonryentrancestairscan be constructed a solidblock locatedcompletelywithinthe width betweenthe revealsof the dooropening. Thesizeof the landingdependson the nature of the entrancedoorand the designof the entrance. The examoleshownhereincludesa modest Iandingjust490 mm deepin frontof an entrancedooropeninginwards.lt is essentialto providean adequatelysizedfoundationto the stairblock,if necessaryseparateto the loadof the basement.The bearingconstruction at a steelsection, internalfloorfinishterminates whichalsofunctionsas the weatherbar for the ooor.

1 2 3 4 6 7 39 40 44 55 57 74 75 76 77 78

232

Loadbearingmasonry Facingbrickwork Air space Walltie Thermalinsulation Reinforcedconcreteslab lmpact sound insulation Floatingscreed Openperpend Wooden door with weather bar Steel section as weather bar Brick-on-edgecourse Reinforcedconcretetreads Reinforcedconcretestairflight Insulatingmasonryunit lvlasonryunits laid in bond in formwork

corner Stairs' Re-entrant

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EEEENEI EEEEI Themasonryexternalbasementstairsshown in detail3.22.3aresupportedon a reinforced concretestairflight.This is cast againstthe soil as a self-supporting flightspanningfromtop to bottom.Normally,the basementwallsand the wallon the otherside of the stairsseparating themfromthe soilare constructedindeoendentlyfromthe stairs. Theexternalwallto the basementin this examplemakesuseof Englishbondand is at least 240mm thick.Thefacingbrickworkto the concretewallon the oppositesidefacingthe soil can be constructedsimilarly.The stairsare thenconstructedindependently betweenthe twowalls.Thejointsat the sidescan be left open.

3.22.3

Re-entrantcorner 3.23.1 Re-entrant cornerwith masonrvsoffit

Themasonryre-entrantcorneris not unknown in masonryconstruction. Hogerand Schumacherhaveusedthis oarticularfeatureon manyoccasions. Thisdetailincreasingly appearsin re-entrant facades,offsetstoreys, arcadesand coveredpassagesor driveways in the examplesof modernmasonryconstruction.A one-brick-thick skinis builtin a proper bondin the botiomof the formworkfor the reinforcedconcreteslab and anchoredto the reinforcedconcretewith mechanicalfixings.The reinforcement is then positionedand the concreteslab cast on top of the brickwork.To avoida cold bridge,it is necessaryto constructthe basecourseof the loadbearingleaf abovethe floorslab usinginsulatingmasonry units.The damp proofcoursein the cavityis builtintothe outerleafabovethe concrete slab.

3.23.1

Construction details

Corner sectionthroughexternal 3.23.2 Horizontal cornerof twin-leafmasonry

The provisionof movementjointsat building cornersis relevantonlyfor the 115mm outer leaf.The separationof the outerleafat the cornerwhichis normallycarriedout reveals the thinnessof the outerleafand hencedemonqualityof stratesthe - often- wallpaper-like the cladding. However,the cornercan also be builtin a properbond.A movementjointmustthenbe incorporatedintothe mainbodyof the wall, Whendoingso, it shouldbe ensuredthatthe distancebetweenthe cornerand the jointdoes not exceedhalfthe maximumrecommended jointspacing.lf thisruleis observed, thenthe jointcan be locatedsatisfactorily withinthe wall. Thejointmay be verticalor may zigzag(veriically)followingthe jointsin the masonry. In contrastto this,an exampleof a negative a steelsectionis also cornerincorporating the corner.Thesteel shown.Thisemphasizes sectionmustbe carefullyfixedto the cornerof leaf. the loadbearing

3.23.2 Free-standingwalls thetopsof free-standing 3.23.3Finishing masonrywalls

masonrywallsof facingbrickFree-standing workare usuallytopped by a precastconcrete or soldiercourse. coping,or a brick-on-edge withjointsfullyfilled workmanship Good-quality morwith mortar(if necessarywater-repellent tar) makesany furtherprotectionunnecessary. Sheetmetalcappingssimilarto thoseusedon masonryparapets(seedetail3.1.1)are,in the opinionof the authors,notsuitablein thissituation. 1 Loadbearingmasonry 2 Facingbrickwork J

3.23.3

24

4 o 19 79 80

Air space Walltie Thermalinsulation Precastconcretecapping Movementjoint Steelangle as cornerprofile