Masonry: Cavity Wall Insulation: Full Fill Isometric cut ... · Thermal continuity checklist 1. Ensure that insulation layers in roof are fitted perpendicularly, to cover junctions

Masonry: Cavity Wall Insulation: Full FillIsometric cut-away view Detail 1.00

Plasterboardshown on dabs

Air tightnessbarrier shown asplaster parge coatInner leaf(block shown)

Wall ties

Outer leaf(render onblock shown)

Insulation tofull fill cavity

LegendInsulation zone

Air tightness barrier(note: this can alsoact as a vapourcontrol layer)

Guidance on thermalcontinuity

Blue text

Guidance on airtightness

Red text

This example should be read in conjunction with the guidance in the introduction to this document. It illustrates the reductionof unwanted infiltration in buildings and provides a Psi value for this junction situation which can be used in calculationprovided the principles outlined and any identified component specification are followed.

Material λ-values usedin calculations(W/mK)

Plasterboard 0.21Insulation (generic) 0.04Plywood sheathing 0.13Brick outer leaf 0.77Mineral wool insulation 0.044Concrete block(dense) protected

1.13

Concrete block(lightweight, high strength)

0.19

Timber frame 0.13Concrete floor beam 2.3Concrete screed 1.15Render (cement/sand) 1.0Gypsum plaster(1000kg/m3)

0.4

Concrete roof tiles 1.5EPDM membrane 0.25Timber battens 0.13Timber flooring 0.13Chipboard 0.13Floor joists 0.13Aluminium 160Steel 50Stainless steel 17Glass 1Sarking felt 0.23Insulation board 0.022

Values used in psi calculations

General guidance notes

Alternative constructions1. Different constructions can be used

to provide an outer leaf e.g. timbercladding, metal cladding, render ontoinsulation. Make sure that theconstruction prevents moistureingress, which can cause thermalbridging. These changes will alsorequire new psi-value calculations tobe carried out.

Sealing membrane junctions2. All membranes should be taped,

stapled or bedded in adhesive asidentified by manufacturer. Repair alltears in membranes beforecommencing next stage of work.

Psi-value calculations3. For details of all thermal conductivity

values of materials used in thepsi-value calculations, see alsoAppendix B of the Introduction.

Masonry: Cavity Wall Insulation - Full fillPitched Roof: Ventilated Roofspace - EavesPsi value = 0.0402W/mK

Thermal continuity checklist

1. Ensure that insulation layers in roof arefitted perpendicularly, to cover junctions

2. Ensure that roof insulation butts againstthe cavity wall insulation, with minimumof 150mm overlap at narrowest point

Air tightness checklist

1. Check that any air tightness barrierused in the ceiling overlaps with thebarrier in the wall

Detail 1.01

Proprietary cross flowventilator to maintainminimum 25mm air gap

Ventilation gap equivalent to10mm minimum continuousopening is required whereroof pitch is above 15°orventilation gap equivalent to25mm minimum continuousopening is required wherethe roof pitch is below 15°

Air tightness barrier onwall, plaster shown

Ventilation gap equivalent to 5mmminimum continuous opening at ridgeis required where the roof pitch isgreater than 35° or the roof span ismore than 10m

Insulation between the masonrywalls. This insulation must betightly fitted, leaving no gaps.

Timber batten to provide tofixing for plasterboard sheets

HEAT 2.7 software image of isothermsthrough junction detail.

For illustrative purposes only.


Design advice

Minimising condensation risk1. Check ventilation paths are clear before

installing insulation above the ceiling

Thermal Resistance of insulation used indetails:

Wall (cavity) - 4.545 (m²K)/WRoof - 9.500(m²K)/W

Note: See detail numbers 1.02 and 1.21 forother junctions using this roof constructionCavity closer (thin calcium

silicate board or similar)

Vapour control layer in ceiling

Note: roof construction, roof pitch andeaves treatment will vary for eachproject. Maintain continuity ofinsulation at wall / roof junction tominimise thermal bridging.

Masonry: Cavity Wall Insulation - Full fillPitched Roof: Ventilated Roofspace - GablePsi value = 0.1436W/mK Detail 1.02



Cavity insulation continuedfull height of gable or to thetop of the loft insulation

Insulation betweenthe last truss andthe gable wall

Air tightness barrier inwall, plaster shown

Timber joist to provide fixingfor plasterboard sheet

Insulation between the masonrywalls. This insulation to be tightly

fitted, leaving no gaps.



2. Ensure that roof insulation butts againstthe gable wall




Design advice




Wall (cavity) - 4.545 (m²K)/WInfill strip at roof truss - 1.136 (m²K)/WRoof - 9.500(m²K)/W

Note: See detail numbers 1.01 and 1.21 forother junctions using this roof construction


Masonry: Cavity Wall Insulation - Full fillPitched Roof: Ventilated Rafter Void - GablePsi value = 0.0501W/mK Detail 1.03

Insulationbetween joistsand inner faceof the cavityinsulation


Timber runner to provide fixingfor plasterboard sheet

Insulation between the masonrywalls. This insulation must betightly fitted, leaving no gaps

Minimum 50mm ventilation path over insulation

Where two insulation types areused together see

supplementary guidance









Design advice





Note: See detail numbers 1.04, 1.05 and 1.22for other junctions using this roof construction

Cavity closer(thin calciumsilicate boardor similar)


Note: thisconstruction istypically usedwhere there arehabitable roomswithin the roofconstruction

Masonry: Cavity Wall Insulation - Full fillPitched Roof: Ventilated Batten Void (warm roof) - EavesPsi value = 0.0688W/mK Detail 1.04

Rigid insulation used as sarkingInsulation to be vapour permeable

Proprietary overfascia ventilator


Insulation betweenthe masonry walls. This

insulation must be tightlyfitted, leaving no gaps

Timber batten toprevent direct path

at ceiling junctionfor air infiltration

Ventilation tobatten void

Vapour permeable membrane(with a vapour resistance ofnot more than 0.25MN.s/g)

Lap roof and wall insulationminimum 50mm thickness atnarrowest point

Ventilation gap equivalent to5mm minimum continuousopening is required at ridgeto batten space



2. Ensure that roof insulation butts againstthe cavity wall insulation, with minimumof 50mm overlap at narrowest point






Design advice






Cavity closer (thin calciumsilicate board or similar)

Vapour controllayer at insulation

Note: this construction istypically used where thereare habitable rooms withinthe roof construction

Note: The ceiling inthis detail is shown

fixed to the undersideof the bottom chordsof the roof trusses. If

engineered timber Ibeams are used, theceiling may be fixedadjacent to the roof

insulation.

Masonry: Cavity Wall Insulation - Full fillPitched Roof: Ventilated Batten Void (warm roof) - GablePsi value = 0.1003W/mK Detail 1.05

Insulation betweenjoists and innerface of the wall


Timber joist to provide fixing forplasterboard sheets


Minimum 50mm ventilation path over insulation

Where two insulation typesare used together see

supplementary guidance

Vapourpermeablemembrane(with a vapourresistance ofnot more than0.25 MN.s/g)









Design advice






Cavity closer (thincalcium silicateboard or similar)

Vapour controllayer in ceiling

Note: this constructionis typically used wherethere are habitablerooms within the roofconstruction

Compressiblefiller

Masonry: Cavity Wall Insulation - Full fillTimber Flat RoofPsi value = 0.0781W/mK

0Detail 1.06

Verge - tightly fit insulationinto void over wall and underdeck (not shown)


Timber batten to provide fixingfor plasterboard sheet


Eaves - fix full height blockingpiece and tightly fit insulation intovoid and under deck

Vapour control layer turned up edgeof roof insulation, lapped with roofwaterproofing layer and sealed

Roofing membrane

Vapour control layer










Design advice


installing insulation above the ceiling2. A vapour control layer is required at

ceiling level, to prevent moisture fromentering into the roof construction

3. The option shown here includes a vapourcontrol layer and insulation as part of amembrane roof construction. Similardetails could be used for a profiled metaldecking roof but consult withmanufacturer regarding ventilationrequirements.



Cavity closer(thin calciumsilicate boardor similar)

Masonry: Cavity Wall Insulation - Full fillTimber Flat Roof with ParapetPsi value = 0.1817W/mK Detail 1.07

Air tightness layer, plaster shown


Compressible filler

Roofing membrane to be taken minimum150mm above finished roof level

Vapour control layer turned up edgeof roof insulation, lapped with roof

waterproofing layer and sealed


Membrane roof construction









Design advice


installing insulation above the ceiling2. A vapour barrier is required at ceiling

level, to prevent moisture from enteringinto the roof construction

3. The option shown here includes a vapourcontrol layer and insulation as part of amembrane roof construction. Similardetails could be used for a profiled metaldecking roof but consult withmanufacturer regarding ventilationrequirements.



Masonry: Cavity Wall Insulation - Full fillLintel at Window HeadPsi value = 0.1744W/mK


1. Check that there is no debris in the cavity2. Install insulation in the window reveal


1. Install window to overlap with outer leafof wall finish.

Alternative:If window lines through with the bottomof the opening in the external finish,some means of preventing a direct lineof air infiltration will be required

2. Install air tightness seal between theinside face of the window and thestructural finish of the window opening.

Insulation to betightly fitted

betweenmasonry walls

Detail 1.08

Insulate the window reveal

Sealant to back of frame

Sealant at window frame

Air tightness tape

Compressible fill

Lintol - any type

Air tightness barrier,plaster shown




Design advice

Minimising condensation risk1. Alternative internal finish at window reveal

- use insulation backed plasterboardGeneral notes2. The window head and jamb details shown

have used a plywood box lining aroundthe window opening in the internal leaf ofthe wall, to allow for window fixings.Alternative details are possible but thecontinuity of insulation and air tightnessshould be considered.


Wall (cavity) - 4.545 (m²K)/WInsulated plasterboard - 1.591(m²K)/W

If position of window head islower than or level with theunderside of the lintol, a largercompressible filler will berequired to stop up a potentialair infiltration route

Detail shows window fixed to plywoodframe set into window opening. If plywoodis used as the sole air tightness layer then

the junction with the layer in the insideface of the wall needs to be taped

Note: the timber batten in window reveal is shown smallerthan actual size, to allow the membrane corner strip to be seen

Note: using acomposite steel lintol

across the wholewall will create major

thermal bridging

Masonry: Cavity Wall Insulation - Full fillWindows and Doors - Jambs and Cills


1. Check that there is no debris in the cavity2. Install insulation in the window reveal


1. Install window to overlap with outer leafof wall finish.

Alternative:If window lines through with the bottomof the opening in the external finish,some means of preventing a direct lineof air infiltration will be required

2. Install air tightness seal between theinside face of the window and thestructural finish of the window opening.

Detail 1.09


Air tightness tape andsealant to back of frame

Sealant at window frame

Air tightness layer,plaster shown


DPC lappedbehind cill andbelow window


Air tightness tape andsealant to back of frame

Compressiblefiller betweenwindow and cill

Air tightness layer,plaster shown

30 minute firerated thermallyinsulated rigidcavity barrier




Design advice

Minimising condensation risk1. Alternative internal finish at window reveal

- use insulation backed plasterboardGeneral notes2. The window head and jamb details shown

have used a plywood box lining aroundthe window opening in the internal leaf ofthe wall, to allow for window fixings.Alternative details are possible but thecontinuity of insulation and air tightnessshould be considered.


Wall (cavity) - 4.545 (m²K)/WInsulated plasterboard - 1.591(m²K)/WInsulated cavity barrier - 3.409(m²K)/W

Cill detail

Jamb detail

Detail shows window fixedto plywood frame set into

window opening

Detail shows window fixed toplywood frame set into windowopening. If plywood is used as thesole air tightness layer then thejunction with the layer in the insideface of the wall needs to be taped

Psi value (jamb)=0.2324W/mK Psi value (cill) = 0.0899W/mK

Note: the timber battens inthe window reveal and cill are

shown smaller than actualsize, to allow the membrane

corner strip to be seen

Masonry: Cavity Wall Insulation - Full fillGround Bearing Floor: Insulation Above SlabPsi value = 0.1979W/mK

20mm strip of perimeterinsulation with thermal

conductivity (λ value) notexceeding 0.025 W/mK around

slab and any screed

Detail 1.10


1. Use a perimeter strip of insulation wherethe concrete slab abuts the concreteblockwork wall

2. Ensure that insulation level in externalwall overlaps with the insulation at thefloor slab


1. Check that any air tightness barrierused in the wall overlaps with thebarrier in the floor

Any wall insulationinstalled below thewall dpc must be fitfor purpose withregards to waterabsorption

External ground level

Seal between the wall and floormembrane with a flexible sealant orseal the gap between skirting board

and floor using a flexible sealant


Damp proof membraneabove or below slab

Vapour control layer belowtimber floor finish




Design advice

Minimising condensation risk1. Check that concrete slab is level and

clear of debris before fitting the insulationat floor level

2. If a screed finish is used instead of a timber floor, use a strip of perimeter insulation with a minimum R value of 0.75 m²/KW for the depth of the screed

Alternative detail3. Using lightweight blockwork (e.g. with λ

value of 0.19W/mK) to improve thethermal performance at the junction wherethe external wall and ground floorconstructions meet will change the psivalue


Wall (cavity) - 4.545 (m²K)/WInsulated perimeter strip - 0.455 (m²K)/WFloor - 3.864 (m²K)/W

Tape corner strip of air tightnessmembrane over wall / floor junction

Masonry: Cavity Wall Insulation - Full fillGround Bearing Floor: Insulation Below SlabPsi value = 0.1801W/mK Detail 1.11


1. Use a perimeter strip of insulation wherethe concrete slab abuts the concreteblockwork wall

2. Ensure that insulation level in externalwall overlaps with the insulation at thefloor slab

50mm strip of perimeterinsulation with thermal

conductivity (λ value) notexceeding 0.025 W/mK around

slab and any screed

Any wall insulationinstalled below thewall dpc must be fitfor purpose withregards to waterabsorption





Damp proof membrane






Design advice

Minimising condensation risk1. If a screed finish is used instead of a

timber floor, use a strip of perimeter insulation with a minimum R value of 0.75 m²/KW for the depth of the screed

Alternative detail2. Using lightweight blockwork (e.g. with λ

value of 0.19W/mK) to improve thethermal performance at the junctionwhere the external wall and ground floorconstructions meet will change the psivalue




Tape corner strip of air tightnessmembrane over wall / floor junction

Masonry: Cavity Wall Insulation - Full fillTimber Suspended Ground FloorPsi value = 0.2191W/mK Detail 1.12

Sub floor ventilation should beprovided, minimum 1500mm²

per run of external wall or500mm² per m² of floor area


Use air tightness tape at junction of airbarrier in wall and floor. Seal between the

wall and floor membrane with a flexiblesealant or seal the gap between skirtingboard and floor using a flexible sealant


Air tightness layer belowtimber floor finish

Solum Damp proof membrane

Insulation directly under flooring - supportedon netting draped over joists and stapled at

the required depths

Minimum 20mm strip ofinsulation with thermalconductivity (λ value) notexceeding 0.025 W/mKshould be installed betweenwall and the last joist

Floor joist ends supported on joisthangers or using scarcement wall


1. Use a perimeter strip of insulationbetween the floor joists and theblockwork wall

2. Ensure that insulation level in externalwall overlaps with the insulation at thefloor construction


1. Ensure that any air tightness barrierused in the wall overlaps with thebarrier in the floor




Design advice

Minimising condensation risk1. Check that all ventilation paths are clear

before installing the floor insulationAlternative detail2. Using lightweight blockwork (e.g.

with λ value of 0.19W/mK) to improvethermal performance at the junctionwhere the external wall and ground floorconstructions meet will change the psivalue

3. If there are concerns about damaging theair tightness membrane in the floor finishduring construction, an additional servicesvoid can be created using timber battenson top of the floor joists



Masonry: Cavity Wall Insulation - Full fillSeparating WallPsi value = 0.0024W/mK

Thermal continuitychecklist

1. Check that there is no debris in cavity2. Install thermally insulated cavity

barrier in line with separating wall

Detail 1.13


1. Ensure that any air tightness barrierused in the internal wall overlaps withthe barrier in the external wall

For more information onacoustic details see

guidance in Section 5 of theTechnical Standards




Design advice

Minimising condensation risk1. Check that insulation is fitted tightly to

concrete block wall at corner junctions


Wall (cavity) - 4.545 (m²K)/WWall (separating) - 1.136 (m²K)/W

Air tightness layer,13mm plaster shown


Plan view

Cavity barrier giving 30 minutefire resistance - ensure cavitybarriers are not breeched by

inappropriate insulation material

Consider using tape cornerstrip of air tightness

membrane at wall junction,to maintain air tightnessbarrier if plaster cracks

Masonry: Cavity Wall Insulation - Full fillConcrete Separating FloorPsi value = 0.054W/mK


1. Check that there is no debris in the cavity.

Detail 1.14


Insulation between the masonry walls.This insulation must be tightly fitted,

leaving no gaps





Design advice

Minimising condensation risk

See general guidance notes

Thermal Resistance of insulation used indetails:Wall (cavity) - 4.545 (m²K)/W

Vapour barrier lapped overcorner junction and taped to

air tightness membrane

Tape corner strip of airtightness membrane over

wall / floor junction



Design stage1. Check that any air tightness barrier

used in the external wall overlaps withthe barrier in the floor

Alternative: If the air tightness barrier is installed

onto the face of the blockwork wall andruns continuously through the floorconstruction, check that there are nogaps or damage in air tightness barrierbefore building the inner leaf of theupper wall

2. If plaster is use as an air tightnessbarrier seal over junction at floor withbarrier tape

Separating floors requireadditional layers and components

to comply with Section 2: Fireand Section 5: Noise

5mm minimum resilient flankingstrip to be used at floor junction. See

Technical Standards GuidanceNotes for Section 5 for details

Masonry: Cavity Wall Insulation - Full fillTimber Intermediate FloorPsi value = 0.0366W/mK Detail 1.15

Insulation between the masonry walls.This insulation must be tightly fitted,

leaving no gaps

Air tightness barrier to becontinuous behind joists

Seal between the wall andfloor membrane with a flexible

sealant or seal the gapbetween skirting board and

floor using a flexible sealant





1. Ensure that any air tightness barrierused in the internal wall is continuousthrough floor construction. Sealaround any penetrations through theair tightness barrier.

Joists shownsupported onjoist hangers




Design advice



Thermal Resistance of insulation used indetails:Wall (cavity) - 4.545 (m²K)/W

Masonry: Cavity Wall Insulation - Full fillGround Floor / Separating Wall junction - Timber susp. floorPsi value = 0.1994W/mK Detail 1.16

Sub floor ventilation should beprovided, minimum 1500mm²

per run of external wall or500mm² per m² of floor area

Use air tightness tape at junction of air barrier in walland floor. Seal between the wall and floor membrane

with a flexible sealant or seal the gap between skirtingboard and floor using a flexible sealant

Air tightness barrier (plaster option shown)

Damp proof membrane

Air tightness barrier belowtimber floor finish

SolumSolum

Insulation directly under flooring -supported on netting draped over joists

and stapled at the required depths


1. Ensure that any air tightness barrierused in the wall overlaps with thebarrier in the floor

2. Consider gluing joints between floorboard


1. Ensure that insulation is tightly fitted tothe back of the masonry wall




Design advice

Minimising condensation risk1. Check that all ventilation paths are clear

before installing the floor insulationAlternative Detail2. Lightweight thermal blockwork can be

used in the separating wall to improve thethermal performance but this will alsoreduce the acoustic performance of thewall. If this alternative is used thenadditional elements will be required tomeet Section 5 of the TechnicalStandards.


Internal Wall - 1.136 (m²K)/WFloor - 5.455 (m²K)/W


Masonry: Cavity Wall Insulation - Full fillConcrete Ground Floor/ Separating Wall: Insulation Below SlabPsi value = 0.202W/mK Detail 1.17



Air tightness barrier (plaster option shown)

Damp proof membrane


1. Ensure that insulation is tightly fittedagainst the separating wall


1. Check that there are no gaps betweenthe wall and floor constructions





Minimum 50mm strip ofinsulation with thermalconductivity (λ value) notexceeding 0.025 W/mKshould be installed betweenwall and the last joist

Design advice

Minimising condensation risk1. If a screed finish is used instead of a

timber floor, use a strip of perimeter insulation with a minimum R value of 0.75 m²/KW for the depth of the screed

Alternative Detail2. Lightweight thermal blockwork can be



Insulated infill strip - 1.136 (m²K)/WFloor - 3.864 (m²K)/W



Tape corner strip of airtightness membraneover wall / floor junction Air tightness barrier lapped over corner

junction and taped to concrete slab

Masonry: Cavity Wall Insulation - Full fillConcrete Ground Floor/ Separating Wall: Insulation Above SlabPsi value = 0.207W/mK Detail 1.18


1. Check that there are no gaps betweenthe wall and floor constructions

2. Ensure that any air tightness barrierused in the wall overlaps onto the floorslab

Air tightness layer, render shown

Damp proof membrane


1. Ensure that insulation is tightly fittedagainst the separating wall




Minimum 20mm strip ofinsulation with thermal

conductivity (λ value) notexceeding 0.025 W/mK

should be installed betweenwall and the last joist

Design advice

Minimising condensation risk1. Ensure that concrete slab is level and

clear of debris before fitting the insulationat floor level

2. If a screed finish is used instead of a timber floor, use a strip of perimeter insulation with a minimum R value of 0.75 m²/KW for the depth of the screed

Alternative Detail3. Lightweight thermal blockwork can be



Internal Wall - 1.136 (m²K)/WInsulated infill strip - 0.455 (m²K)/WFloor - 3.864 (m²K)/W


Tape corner strip of airtightness membraneover wall / floor junction

Seal between the wall andfloor membrane with a flexible

sealant or seal the gapbetween skirting board and

floor using a flexible sealant

Air tightness barrier lappedover corner junction and

taped to concrete slab

Masonry: Cavity Wall Insulation - Full fillConcrete Intermediate Floor / Separating Wall junctionPsi value = 0.2698W/mK Detail 1.19

Air tightness barrier lappedover corner junction



Separating floors requireadditional layers and componentsto comply with Section 2: Fire and

Section 5: Noise


1. Ensure that any air tightness barrierused in the internal wall overlaps withthe barrier in the floor or ceiling


1. Ensure that there are no gaps betweenfloor slabs or between the top of the walland the underside of the floor slab.

2. Ensure that the insulation is tightly fittedto the top of the floor slab.




Design advice

Minimising condensation risk1. Check that concrete slab is level

and clear of debris before fittingthe insulation at floor level



5mm minimum resilient flankingstrip to be used at floor junction. See

Technical Standards GuidanceNotes for Section 5 for details

Masonry: Cavity Wall Insulation - Full fillTimber Intermediate Floor / Separating Wall junctionPsi value = 0.0028W/mK Detail 1.20

Air tightness barrier in to becontinuous behind joists



Separating floors requireadditional layers and components

to comply with Section 2: Fireand Section 5: Noise


1. Ensure that there are no gaps betweenthe floors and the separating wall


1. Ensure that any air tightness barrier usedin the internal wall overlaps with thebarrier in the floor or ceiling

Alternative:If the air tightness barrier is installed ontothe face of the blockwork wall and runscontinuously through the floorconstruction, infill any gaps where floorfixing is made to external wall




Design advice




Infill insulation in between joists


Masonry: Cavity Wall Insulation - Full fillPitched Roof: Cold Roof / Separating Wall junctionPsi value = 0.0934W/mK Detail 1.21


1. Install a cavity barrier at the top of the wall2. Ensure that insulation layers in the roof are

fitted perpendicularly, to cover junctions


1. Check that there are no gaps betweenthe top of the masonry wall and theunderside of the roof

2. Check that the air tightness barrierused in the ceiling overlaps with thebarrier in the wall




Air tightness barrier,plaster shown Minimum 50mm strip of rigid

insulation with thermal conductivity(λ value) not exceeding 0.025

W/mK should be installed betweenwall and the last joist

Design advice




Roof - 9.500(m²K)/W

Note: See detail numbers 1.01 and 1.02 forother junctions using this roof construction

Cavity barrier giving 30minute fire resistance -ensure cavity barrier is notbreeched by inappropriaterigid sheathing insulationmaterial



Masonry: Cavity Wall Insulation - Full fillPitched Roof: Ventilated Batten Void/ Separating Wall junctionPsi value = 0.1141W/mK Detail 1.22

Cavity barrier giving 30minute fire resistance -ensure cavity barrier is notbreeched by inappropriaterigid sheathing insulationmaterial


50mm ventilation path over insulation

Where two insulation types areused together see supplementary

guidance


1. Install a cavity barrier at the top of the wall2. Ensure that insulation layers in roof are

fitted perpendicularly, to cover junctions


1. Check that there are no gaps betweenthe top of the masonry wall and theunderside of the roof

2. Ensure that the air tightness barrierused in the ceiling overlaps with thebarrier in the wall




Design advice




Internal Wall - 1.136 (m²K)/WInfill strip at joists - 1.818 (m²K)/WRoof - 9.500(m²K)/W




Note: this construction istypically used where thereare habitable rooms withinthe roof construction

Masonry: Cavity Wall Insulation - Full fillWall JunctionPsi value = 0.0645W/mK Detail 1.23

Plan view

Use one continuous pieceof insulation around the

corner junction


Insulation betweenthe masonry walls.This insulation mustbe tightly fitted,leaving no gaps


1. Check that there is no debris in the cavity


1. Check that any air tightness barrierused in the external walls overlapsat the corner




Design advice




Wall (cavity) - 4.545 (m²K)/W

Masonry: Cavity Wall Insulation - Full fillWall Junction - Inward Corner Psi value = -0.1191W/mK Detail 1.24

Plan view


Insulation between themasonry walls. This

insulation must be tightlyfitted, leaving no gaps. Use

one continuous piece ofinsulation around the

corner junction.




1. Ensure that any air tightness barrierused in the external walls overlaps atthe corner




Design advice




Wall (cavity) - 4.545 (m²K)/W

Documents

Masonry: Cavity Wall Insulation: Full Fill Isometric cut ... · Thermal continuity checklist 1. Ensure that insulation layers in roof are fitted perpendicularly, to cover junctions