interior insulation of masonry wallsinfo.tuwien.ac.at/cesbp/presentations/w-1.1/05_int...interior...

Interior Insulation of Masonry Walls Assessment and Design

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Dr. ir. Paul Steskens & ir. Xavier Loncour, Belgian Building Research Institute

Prof. dr. ir. Staf Roels & ir. E. Vereecken, KU Leuven

September 11 2013

Contents

Introduction

Problem Definition

Research Objective

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Methodology

Results

Conclusions

IntroductionInterior Insulation of masonry facades

Historical buildings

Urban environment

Hygrothermal risks

• Moisture load and frost damage risk

• Interstitial and summer condensation

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• Interstitial and summer condensation

• Thermal bridges

• Infiltration, exfiltration and circulation of airflow

Uncertainty

• Type of interior insulation

• Quality of materials and realization

• Indoor climatic conditions

• …

IntroductionInterior Insulation of masonry facades

Historical buildings

Urban environment

Hygrothermal risks

• Moisture load and frost damage risk

• Interstitial and summer condensation

Previously:Building professionals have been

kept from the application of

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• Interstitial and summer condensation

• Thermal bridges

• Infiltration, exfiltration and circulation of airflow

Uncertainty

• Type of interior insulation

• Quality of materials and realization

• Indoor climatic conditions

• …

kept from the application of

interior insulation

Nowadays:Risks are manageable and

controllable

But, proper diagnosis

and design is required!

Problem DefinitionDiagnosis and design of interior insulation

Hygrothermal modeling and simulation

• Influence of a specific interior insulation system on masonry

facade is analyzed

• Requires specific knowledge of material properties

• Time-consuming

• Relatively complex

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Guidelines

• WTA guidelines (Germany), Videncenter for energibesparelser i

bygninger (Denmark)

• No concise assessment tool

• Strongly dependent of building engineer’s expertise and

experience

Strong desire for an assessment tool in order to analyze the

applicability of interior insulation

Development of Assessment Tool• helps the building designer determine whether interior insulation is possible

• serves as a basis for selection and design of the insulation system

• is independent of building engineer’s, architect’s expertise and experience

Research Objective

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State-of-the-Art

Methodology

Practical Experience

Tool Development

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Tool Development

Validation

ImprovementCase Studies

Assessment Framework (Tool)

Interior insulation is

applicable

Applicability is unknown Interior insulation is not

recommended

Visible Damage

Moisture load and frost

damage risk

Structure

• 4 Key Performance Indicators (KPIs)

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Material properties of

the existing masonry

wall

Indoor Climate

State of the facade:

• complies with the requirements in the green column

• corresponds to the description in the red column (for one or more KPIs)

• meets the description in the orange column

Assessment FrameworkCase Study - Example• Traditional row-house in city-center of Louvain (Belgium)

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Assessment Framework (Tool)

Interior insulation is

applicable

Applicability is unknown Interior insulation is not

recommended

Visible Damage

Moisture load and frost

damage risk

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Material properties of

the existing masonry

wall

Indoor Climate

Assessment FrameworkVisible damages• Cracks

• Moisture problems (stains, efflorescence of salts, …) or sources

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Assessment FrameworkVisible damages• Cracks

• Moisture problems (stains, efflorescence of salts, …)

Stains caused by dripping water

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Protection against water

Stains caused by dripping water

Assessment FrameworkInterior insulation is

applicable

Applicability is unknown Interior insulation is not

recommended

Vis

ible

Da

ma

ge

No visible damage (traces of

moisture in the

interior/exterior finish, such

as irregularities, stains) or

moisture sources

No visible damage, however,

presence of moisture sources

(for example rising damp)

which may lead to moisture

problems and damage after

installing the insulation

Presence of moisture (stains,

moisture ingress, efflorescence of

salts, algae, cracks, irregularities)

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Vis

ible

Da

ma

ge

Improvement:• Eaves (reduced moisture load)

Assessment Framework (Tool)

Interior insulation is

applicable

Applicability is unknown Interior insulation is not

recommended

Visible Damage

Moisture load and frost

damage risk

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Material properties of

the existing masonry

wall

Indoor Climate

Assessment FrameworkWind-driven rain load• Thickness of the facade

• Orientation, geographical area

• Height

Wooden beams and floors

Technical Installations

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Technical Installations• Water conducting pipes/ducts

Assessment FrameworkWind-driven rain load• Thickness of the facade

• Orientation, geographical area

• Height

Wooden beams and floors

Technical Installations

1½-stone thick

Urban environment

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Technical Installations• Water conducting pipes/ducts

Wooden beams are

removed/replaced

Interior insulation is applicable Applicability is unknown Interior insulation is not

recommended

Mo

istu

re l

oa

d a

nd

fro

st d

am

ag

e r

isk

Typology of the existing façade and exposure to rain

Solid masonry facade having a width

of two stones or thicker, or (≤ 1½

stone) exposed to a relatively small

(wind-driven) rain load

Solid concrete wall

1½ stone (exposed to a

moderate/high rain load)

≤ 1 stone (exposed to a

moderate/high rain load)

Non-insulated cavity wall

Insulated cavity wall

Internal wall

Assessment Framework - Example

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Mo

istu

re l

oa

d a

nd

fro

st d

am

ag

e r

isk

Internal wall

Floor Construction

Concrete floor or wooden floor,

which is not connected to the facade

Undamaged wooden construction

which is connected to the facade

Wooden construction, connected to

the façade, containing moisture

damages

Technical Installations

• Water pipes or ducts, which are

susceptible to frost or frost damage

are not present

• Technical installations which do not

require the penetration of the

interior insulation are not present

Water pipes or ducts, which are

susceptible to frost are frost

damage are present

Assessment Framework (Tool)

Interior insulation is

applicable

Applicability is unknown Interior insulation is not

recommended

Visible Damage

Moisture load and frost

damage risk

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Material properties of

the existing masonry

wall

Indoor Climate

Assessment FrameworkMaterial properties of the existing facade• Exterior finish (plaster, tiles, varnished bricks, water-repellent coating, …)

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Bricks and Mortar joints• Frost resistance of bricks and mortar

Interior finish• Degradation, loose parts, …

• No vapor retarding layers (wall-paper)

• Remove contaminations

• Provide supportive subsoil with sufficient carrying capacity

Assessment FrameworkMaterial properties of the existing facade• No exterior finish

Bricks and Mortar joints• No visible frost damage

Interior finish• Removal of wall-paper

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• Removal of wall-paper

Interior insulation is applicable Applicability is unknown Interior insulation is not

recommended

Ma

teri

al

pro

pe

rtie

s o

f th

e e

xis

tin

g m

aso

nry

wa

ll

Exterior finish

No exterior finish or an exterior finish

which has a good condition, has a

good quality, and is vapour-open

Exterior finish which has not a good

condition, and/or contains damages

Vapour retarding exterior finish such

as varnished bricks, tiles, mosaic,

vapour-retarding paint

Bricks

In accordance with NBN 771, Very No visible frost damage Visible frost damage, brick susceptible

Assessment Framework - Example

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Ma

teri

al

pro

pe

rtie

s o

f th

e e

xis

tin

g m

aso

nry

wa

ll

In accordance with NBN 771, Very

resistant to frost damage (NBN B27-

009/A2 or DIN 52252-1)

No visible frost damage Visible frost damage, brick susceptible

to frost damage

Mortar joints

In accordance with NBN 771, Very

resistant to frost damage

No visible frost damage Visible frost damage, mortar

susceptible to frost damage

(NBN B27-009/A2 or DIN 52252-1) Lime mortar (for ex. mortar containing sandy clay)

Interior finish

No visible damage

No irregularities or loose parts

Smooth, non-structured surface

Irregularities and/or loose parts

Very structured/irregular surface

Interior finish which is susceptible to

moisture (damage)

Vapour retarding interior finish

Visible damage (for example cracks,

paint which is flaking off, degraded

plaster)

Assessment Framework (Tool)

Interior insulation is

applicable

Applicability is unknown Interior insulation is not

recommended

Visible Damage

Moisture load and frost

damage risk

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Material properties of

the existing masonry

wall

Indoor Climate

Assessment FrameworkIndoor climate• Humidity class (≤3) according to EN ISO 13788

• Well-controlled and efficient ventilation and heating system

Humidity class Building

1 Unoccupied buildings, storage of dry goods

2 Offices, dwellings with normal occupancy and ventilation

3 Building with unknown occupancy

4 Sport halls, kitchens, canteens

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4 Sport halls, kitchens, canteens

5 Special buildings, e.g. laundry, brewery, …

Interior insulation is applicable Applicability is unknown Interior insulation is not

recommended

Ind

oo

r C

lim

ate

Indoor climate

Indoor Climate Class 3 according to

ISO EN 13788

Indoor Climate Class 4 according to

ISO EN 13788

Indoor Climate Class 5 according to

ISO EN 13788

HVAC System

Well-controlled and efficient

ventilation, climate control and

Insufficient ventilation

Assessment Framework

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heating system

Assessment Framework

Interior insulation is

applicable

Applicability is unknown Interior insulation is not

recommended

Visible Damage

Moisture load and frost

damage risk

Case Study - Example

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Material properties of

the existing masonry

wall

Indoor Climate

State of the façade complies with the requirements in the green column:

Interior insulation is applicable

Additional ResultsCase Study - Example

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Conclusion and DiscussionAssessment Framework (Tool) for the Assessment of the

Applicability of Interior Insulation has been developed• helps the building designer determine whether interior insulation is possible

• critical hygrothermal risks are taken into account

• serves as a basis for selection and design of the insulation system

• is independent of building engineer’s, architect’s expertise and experience

Further Development

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Further Development• Framework is applicable for vapor-retarding interior insulation systems

• Tool is extended for capillary-active systems

• Additional validation/verification

Thank you very much for your attention!

Questions?

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paul.steskens@bbri.be

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