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Increasing Construction Quality of External Thermal Insulation Composite System (ETICS) by Revealing on-site Degradation Factors

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Virgo Sulakatko at Tallinn University of Technology
Virgo Sulakatko
Eneli Liisma at Tallinn University of Technology
Eneli Liisma
Erki Soekov
Erki Soekov
Erki Soekov
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Abstract and Figures

The installation of External Thermal Insulation Composite System (ETICS) enables to protect building envelope from natural weather effects and increase energy efficiency. As the system can be installed externally with simple work methods the usage is growing in European countries. The quality of the outcomeisinfluencedby design, material selection, and on-site construction process. The on-site fixing process of ETICS is guided by numerous regulations and guidelines which have aninsignificant impact on the actual construction technology. A list of Degradation Factors (DF) is created to classify the relevant on-site activities.
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Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
1878-0296 © 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/).
Peer-review under responsibility of the organizing committee of SBE16.
doi: 10.1016/j.proenv.2017.03.160
Available online at www.sciencedirect.com
ScienceDirect
International Conference on Sustainable Synergies from Buildings to the Urban Scale, SBE16
Increasing Construction Quality of External Thermal Insulation
Composite System (ETICS) by Revealing on-site Degradation
Factors
Virgo Sulakatkoa,b,*, Eneli Liismaa, Erki Soekova
aTallinn University of Technology, Ehitajate Street 5, 19086 Tallinn, Estonia
bTechnische Universität Berlin, Strasse des 17. Juli 135, 10623 Berlin, Germany
Abstract
The installation of External Thermal Insulation Composite System (ETICS) enables to protect building envelope from natural
weather effects and increase energy efficiency. As the system can be installed externally with simple work methods the usage is
growing in European countries. The quality of the outcome is influenced by design, material selection, and on-site construction
process. The on-site fixing process of ETICS is guided by numerous regulations and guidelines which have an insignificant
impact on the actual construction technology. A list of Degradation Factors (DF) is created to classify the relevant on-site
activities.
Categorised on-site Degradation Factors are basing on various studies, standards, and regulations set for products. The
shortcomings are categorised in eight sets: substrate, mixtures, adhesive, insulation, anchors, reinforcement, finishing layer and
auxiliary materials. Additionally, a field study has been conducted to test the occurrence of on-site shortcomings in Estonia. The
collected measurements and observations did not reveal severe and systematic installation failures, but random deviations
occurred in most layers which might lead to the degradation of ETICS.
The paper categorises on-site shortcomings which can lead to the loss of technical performance during the service life of the
façade.
© 2017 The Authors. Published by Elsevier B.V.
Peer-review under responsibility of the organizing committee of SBE16.
Keywords: Degradation of facades; thin-layer rendering system; External Thermal Insulation Composite System; ETICS; construction process
* Corresponding author. Tel.: +372-620-2465; fax: +372-620-2453.
E-mail address: virgo.sulakatko@ttu.ee
© 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/).
Peer-review under responsibility of the organizing committee of SBE16.
766 Virgo Sulakatko et al. / Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
1. Introduction
Energy efficiency of the existing buildings can be increased by improving the external envelope of the building.
One of the often used solutions in Europe is to install External Thermal Insulation Composite System (ETICS). The
system can be applied externally with simple work methods. Each layer of the system is designated to provide
particular value and has a significant role in the long-term durability. The outcome of the façade is influenced by
numerous factors which alter the quality of the building1. Arising defects and reduced thermal properties of the
building are related to on-site activities for 66% of the cases2. To evaluate the economic and technical impact of
construction technology, on-site activities which modify essential characteristics need to be identified. The
application process directly influences the calculated energy consumption, performance requirements and the
technical properties of building materials. The conducted analysis identifies and categorises relevant activities which
can alter the performance of the façade system.
2. The Field Study to test technology shortcomings on construction sites
Based on quality control requirements established by product manufacturers’ guidelines a field study has been
conducted to reveal additional on-site construction process shortcomings in Estonia. Seven buildings were selected,
and observations repeated four times on each construction site during the autumn season which is the most
problematic for facades. Although the layers of ETICS are installed and covered swiftly, the field study enabled to
investigate the activities of craftsmen during the application of different layers.
The collected measurements and observations revealed no severe and systematic installation failures, but random
deviations occurred in most layers. It can be pointed out that the characteristics of work methods are craftsmen
specific and repeated by the person during the ongoing application. The most common shortcomings were:
x application during unsuitable climate conditions,
x increased gap width between insulation plates,
x reduced overlap of reinforcement mesh, and
x crossed joints of the insulation plates.
In autumn season of Nordic climate, the temperature might fall unexpectedly below zero degrees during night
time, and the amount of rainfall is high. The applied thin layers have an increased risk of freezing, and the
environment should be controlled to reduce the risk of unsuitable climate conditions. During the observations, it is
noted that three facades from seven were covered with tarpaulin, and one of them was also heated. The results lead
to the assumption that the potential risk of short-term freezing is relatively high.
Gaps between insulation plates affect the thermal resistance of the external envelope and cause reduced long-term
resistance in the areas. During the field study, the gap width between insulation panels was measured, and the after
treatment observed. The recommended gap width (2mm) was exceeded by most of the measured areas. 69% of them
were filled with foam or wedge, 31% were left unfilled. Although the slightly wider unfilled gap has no significant
effect on thermal conductivity, the intruding mortar causes different thermal expansion in the area increasing the
risk of crack formation.
Occasional failures have been noted during the application of reinforcement layer. To ensure the ability to bypass
tensions the overlapping of mesh should be at least 100mm, diagonal mesh placed on the corners of the openings,
and the crossed joints for insulation plates avoided. Observations revealed that these requirements are mostly met,
but individual shortcomings for each of the mentioned requirement were noted on the construction site. The layers
of ETICS need to provide sufficient technical performance. If one layer in a given area has a critical shortcoming, a
degradation will occur. To ensure economic and technical efficiency for the owner the occurrence of relevant
Degradation Factors should be minimised.
3. Relevant on-site Degradation Factors
The on-site Degradation Factors (DFs) are classified by the layer of ETICS – substrate, adhesive, insulation,
mechanical anchors, reinforcement and finishing layer. Common factors for mixtures and auxiliary details are
considered separately.
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Virgo Sulakatko et al. / Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
3.1. Substrate
The existing exterior wall of the building should be able to resist the additional loads caused by ETICS and is
responsible in large extent for the stability or adhesive characteristics of the system. The relevant on-site DFs are
summarised in Table 1.
Layers surface conditions influence the adhesive bond between applied and existing materials. To provide
sufficient adhesive properties and bear additional loads the substrate irregularities should be pre-treated. The
minimum bond strength (0.08 N/mm2) needs to be fulfilled to tolerate wind suction load, natural weight,
hygrothermal loads, and internal movements of the structure3. The penetration rate of viscous fluids depends on
various preparation works which aim to increase the access to pores4. Substrates with biological growth, dirt, oil or
similar create an adhesion prohibiting layer while old paint can create a chemical reaction between the layers,
causing loss of stability of insulation plates. Beside the adhesion properties, unfavourable climate conditions during
construction process influence the physical properties of the substrate5. Humid substrates affect the cracking
sensitivity, increase flexural strength (flexural strength) and bending modulus (flexural modulus) of the mortar6.
Table 1. Degradation factors for the substrate preparation.
ID
Degradation Factor
S1
Substrate is covered with grease/oil
S2
Substrate is covered with dust/dirt
S3
Substrate is covered with biological growth
S4
Substrate is covered with paint or other material which can chemically react with adhesive
S5
Substrate is under required load bearing capacity
S6
Substrate has defects, detached areas or is uneven
S7
Smooth substrate surface or the adhesive is not suitable
S8
Substrate has low humidity
S9
Substrate is wet; internal moisture level is high
3.2. Common factors for mixtures
The properties of the mixtures depend on the ingredients, storage conditions and application process. The
potential DFs for the mixtures are summarized in Table 2.
Table 2. Common Degradation Factors for mixtures.
ID
Degradation Factor
M1
Wrong material storage conditions
M2
The mixing procedures do not remove clots
M3
High share of kneading water
M4
Low share of kneading water
M5
High purity of kneading water
M6
Increased aggregate (i.e. sand) share
M7
Increased binder (i.e. cement) content
M8
Not recommended ingredients added to adhesive mixture
M9
Low temperature (freezing) during application and/or curing process
M10
Hot curing conditions
M11
Dry curing conditions
M12
Usage of winter mixtures if weather conditions are not suitable
768 Virgo Sulakatko et al. / Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
Only laboratory tested specific ingredients are allowed to be added if the product manufacturer foresees it. The
prefabricated mixtures are not authorised to be altered on site and preparation works need to hold the right dosage of
kneading water and sufficient mixing process7–9.
During the application process, it is important to follow the climatic conditions foreseen by the producer of the
material. High temperatures lead to fast dehydration and cracking due to tensions caused by rapid shrinkage. Low
temperatures cause frost damage, which can be seen if snowflake shaped minor cracks occur shortly after
application. They result to detachment of layer.
3.3. Adhesive
Correctly applied adhesive layer reduces stability concerns of the whole sysem10. To limit the DFs, only
insulations based on polystyrene and mineral wool are examined in this study. For the application of the adhesive
mainly bead-point method is used for polystyrene based insulation and the full area is covered with mineral wool
based insulation materials.
The bead-point method foresees that the insulation plate’s border zones and the middle section are covered with
adhesive. The size of adhesive should be between 40% to 100% depending on the type of fixture (bonded and/or
fixed) and insulation material. The possible DFs are summarized in Table 3.
If it is required to cover the full area (bonded ETICS) or the substrate layer is very smooth, treatment with notch
towel should be conducted to be able to level the substrate unevenness3. It ensures the needed bond strength and
prevents the bowing out of the insulation plate if the application is carried out with enough pressure. Without the
pressure, the adhesion strength between adhesive and substrate will be too weak due to hollow areas.
The middle adhesive dots (bead-point method) prevent the arching out, which can cause a crack formation near
the edges, slightly inner the side. Summer season increases linear thermal expansions and affects the aspect of
stability. The adhesive on the borders prevents the bending out of the sides, which causes crack formation directly
on the edge of the plate. During the winter season, peeling stresses in adhesive layer are higher than in summer, and
thermal effects increase tensions near the edges. Additionally, correct adhesive installation prevents airflow behind
insulation, improving safety in case of fire11.
If an insufficient amount of adhesive is applied during the construction process, the stability of the system is
reduced while increased adhesive area can decrease the soundproof properties up to 3dB3.
Table 3. Degradation factors of the adhesive layer.
Degradation Factor
Missing insulation on the edges (polystyrene)
Missing insulation in the centre (polystyrene)
Insufficient adhesive
Adhesive not rubbed into insulation plate (mineral wool)
Adhesive is not treated with notch towel
Increased area covered with adhesive
Working time of the adhesive is exceeded
Lack of pressure during application of insulation plates
Large unevenness of the adhesive layer
3.4. Insulation
The characteristics of the insulation material influence mainly the thermal conductivity of the façade.
Shortcomings in the construction technology shown in Table 4 can additionally alter to a significant extent the
stability of the system and corrosion protection characteristics. The properties can be modified with UV-Radiation,
short drying-out period, usage of wet material or by shortcomings during application activities.
After the first months of production of the product, moisture diffusion initiates the shrinking process. To avoid
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Virgo Sulakatko et al. / Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
cracking the insulation plates must have finished the diffusion process3. If the materials get wet during storage or
application, the moisture will be trapped in the system for a longer period, and internal moisture decreases expected
corrosion protection12. The drying-out period is depending on vapour diffusion resistance of the system and is
causing the reduction of pull-off strength after the first four months of application and reduce adhesion properties13.
Laboratory tests show that the drying-out period might last up to 12 years14. Usually, the duration of drying out
period of mineral wool in ETICS is up to six months and up to two years polystyrene based insulation. Internal
moisture level determines the activation of corrosion protection. Besides wetting, exposure to UV radiation alters
the material structure on the exposed side reducing adhesion.
Table 4. Degradation factors for insulation material application.
ID
Degradation Factor
I1
Material is exposed to UV-radiation for a longer period
I2
Insulation plates are installed shortly after manufacturing
I3
Wet insulation plates
I4
Continuous gaps between substrate and insulation material (opened to air entry)
I5
Insulation plate vertical joints are crossed or too close
I6
Corners of the openings have crossed joints
I7
Insulation plates joint width is too wide or not aligned
I8
Height difference between insulation plates
I9
Broken areas of the insulation plates are not filled
I10
Missing or too narrow fire reluctant areas
During the installation process, the crossed joints between insulation plates should be avoided as they cause gaps
between insulation plates and increase the risk of height difference. The height difference creates thinner layers in
reinforcement layer and the risk of cracking increases. Gaps between insulation plate joints should be avoided by
installing the plates tightly next to each other. If gaps are present, the mixture fills the areas to some extent, causing
thicker layer in the particular region, resulting cracks due to the shrinking of materials3.
3.5. Mechanically fixed anchors
The performance requirements set for mechanical anchors can be altered by using an unsuitable anchor or by the
poor application. The DFs are presented in Table 5. Mainly plastic anchors which have a screw or a nail as
expansion element are used. To bear wind suction load calculated amount of anchors, with specified length and load
bearing class need to be used. As a secondary effect, it is also noted that the increased number of mechanical
anchors decrease the soundproofing of the system in some extent3.
Table 5. Degradation factors for insulation material application.
ID
Degradation Factor
A1
Increased diameter of drilled anchor hole
A2
Decreased diameter of anchor plate
A3
Decreased amount of anchors
A4
Increased amount of anchors
A5
Location is not as foreseen
A6
Anchor plate is installed too deeply into insulation material
A7
Anchor plate is placed too high
A8
Amount of anchors is not increased in the corners
A9
Unsuitable anchor type
A10
Hole of the anchor is not cleaned
770 Virgo Sulakatko et al. / Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
During the application process, a decreased depth of an anchor hole can cause height difference of the anchor
plate. In the case when the plate lies on the higher level, decreased render thickness will dry out faster in comparison
to other areas. During repeated wetting and drying the durability will decrease to 10 years as the hygrothermal tests
have shown3. Frictional strength between the cavity wall and the anchor can be influenced by increased diameter of
drilled anchor hole or no dust removal.
3.6. Reinforcement layer
The stresses caused in the system are transmitted to the reinforcement layer and in the applied mesh. The ability
to transmit stresses can be modified during mesh or mortar application with DFs summarised in Table 6.
The stresses can be directed successfully only if the mortar fills the inner areas of the net. During the installation
process, the layer should be applied in wet to wet conditions and the mesh should be pressed into the mixture. The
covering layer should be installed shortly, as the mixture is not cured to prevent separation of layers3. During
construction works, it is needed to spectate whether the mesh is free of folds, not broken not without hollow areas.
Compatible meshes with enough overlapping are necessary. Otherwise the ability to resist to occurring tensile forces
is harmed.
Diagonally placed additional nets should be applied on the corners of openings as notch stresses occur. The
supplementary mesh should be installed together with the main mesh and covered as usually in not cured conditions
(wet to wet). In the circumstance of missed mesh, diagonal cracks occur3.
Table 6. Degradation Factors of the reinforcement layer.
ID
Degradation Factor
R1
Too smooth external layer of the insulation plate
R2
Decreased overlap of the mesh
R3
Folded mesh
R4
Missing diagonal mesh
R5
Mesh not filled with mortar, unsuitable placement in the layer
R6
Thin mortar layer
R7
Layer is not applied in wet to wet conditions
R8
Not compatible mesh is used
3.7. Finishing coat
The external layer is beside aesthetic function responsible for weather protection. Natural conditions comprise of
a combination of effects - the wind, rain, pollutants, relative humidity, temperature and solar radiation15. As failure
occurs, water penetrates into the system and causes moisture-induced problems. Possible construction technology
related DFs are summarised in Table 7.
Table 7. Degradation Factors of the finishing coat.
ID
Degradation Factor
F1
Missing primer
F2
Reinforcement mixture or primary coat is not cured
F3
Thick render layer/ differences in thickness
F4
Thin render layer (thinner than single grain diameter)
The cracks can be considered dangerous if they are 0.2mm wide for polystyrene based insulation and 0.3mm for
mineral wool based insulations3. To prevent crack formation, a primer should be applied if the system producer
requires it. It ensures the necessary adhesive properties between render and reinforcement layer. In the case of
failure the reduced adhesive properties detaching can occur due to capillary water uptake and storage between the
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Virgo Sulakatko et al. / Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
layers.
The application process is important to follow the required climatic conditions and thickness of the layer.
Increased thickness and high temperatures lead to fast dehydration and cracking due to tensions caused by fast
shrinkage.
3.8. Details and specific regions
Specific technical solutions for particular areas of ETICS are developed rapidly by product manufacturers, and an
increased amount of technical installation options are provided by the product manufacturers or by the designers. To
reveal a comparative overview of problematic areas in the further research the construction technology related
problems of auxiliary details and specific regions are summarised in Table 8 in a more holistic perspective.
Table 8. Degradation Factors for specific details.
ID
Degradation Factor
X1
Structural expansion joint is not installed/finished properly
X2
Windowsill is not finished properly (i.e. curved upwards, proper sealants)
X3
Unsolved rainwater drainage (i.e. drainpipe or drip profiles not used)
X4
Fixed frame connection is not finished accurately (i.e. missing sealants)
X5
Roof edge covers are not installed properly (i.e. vertical detail too short)
X6
Shock resistance solution is unsuitable (i.e. no double reinforcement
mesh, corner details with metal or additional protective plate installed)
X7
Unfinished penetrations through the system (i.e. fixed without sealants)
X8
Plinth details are not installed properly (i.e. incorrect fixing, overlapping
of details, protruding from render)
The areas to be evaluated are structural expansion joints, windowsills, rainwater drainage, fixed frames, roof edge
covers, plinth details, penetration through the system and solutions for shock resistance. The summarised DFs
consist of the most problematic areas of the façade which have an impact on the performance. The auxiliary details
should be planned and applied in a way that water could not penetrate into the system, and internal tensions do not
harm the layers. Therefore, during the design and construction works the holistic requirements set for the system
should be met.
4. Conclusions
Each layer of ETICS needs to fulfil specific requirements while the performance of the layer can be altered by
material selection, design, and on-site construction activities. Shortcomings during construction often cause defects
on the facade or reduced thermal efficiency of the building. To reveal most relevant on-site shortcomings the lists of
Degradation Factors is proposed by the applied layers. Each of the DF has an impact on the system performance and
should be conducted with care. Critical shortcomings during construction process can lead to the loss of technical
performance during the service life of the façade and have an economic and social impact to the owners. By
revealing the on-site Degradation Factors, it is possible to evaluate the technical and economic relevance of each
factor. The knowledge enables to improve the quality of on-site construction process.
Acknowledgements
This work was supported by institutional research funding of the Estonian Ministry of Education and Research
IUT1−15 “Nearly-zero energy solutions and their implementation on deep renovation of buildings“.
772 Virgo Sulakatko et al. / Procedia Environmental Sciences 38 ( 2017 ) 765 – 772
References
1. Sulakatko V, Lill I, Liisma E. Analysis of On-site Construction Processes for Effective External Thermal Insulation Composite System
(ETICS) Installation. Procedia Econ Financ 2015;21:297–305.
2. Sulakatko V, Lill I, Liisma E. Towards Nearly Zero-Energy Buildings through analyzing reasons for degradation of facades. Procedia Econ
Financ 2014;18:592–600.
3. Cziesielski E, Vogdt FU. Schäden an Wärmedämm-Verbundsystemen. Fraunhofer IRB Verlag: Stuttgart; 2007.
4. Silva A, Dias JL, Gaspar PL, De Brito J. Statistical models applied to service life prediction of rendered façades. Autom Constr 2013;30,151–
160.
5. Flores-Colen I, De Brito J, Branco F. In situ adherence evaluation of coating materials. Exp Tech 2009;51–60.
6. Balayssac JP, Nicot P, Ruot B, Devs O, Détriché CH. Influence of admixtures on the cracking sensitivity of mortar layers applied to a mineral
substrate. Constr Build Mater 2011;25, 2828–2836.
7. Amaro B, Saraiva D, De Brito J, Flores-Colen I. Inspection and diagnosis system of ETICS on walls. Constr Build Mater 2013;47,1257–1267.
8. Silva CM, Flores-Colen I, Gaspar S. Numerical analysis of renders’ adhesion using an interface model. Constr Build Mater 2013;38,292–305.
9. Fernandes V, Silva L, Ferreira VM, Labrincha JA. Evaluation of mixing and application process parameters of single-coat mortars. Cem Concr
Res 2005;35,836–841.
10. Collina A, Lignola GP. The External Thermal Insulation Composite System (ETICS): More than Comfort and Energy Saving. 3o Congr Port
Argamassas Construção 2010.
11. Künzel HM. Außendämmung bei Bestandsbauten Schäden, Ursachen, Instandsetzungen. Schäden beim energieeffizienten Bauen 2010;37–45.
12. Zirkelbach D, Künzel HM, Slanina P. Einfluss von Undichtheiten bei der Sanierung von Plattenbauten mit Wärmedämm-Verbundsystemen.
WTA-Almanach 2008;285–297.
13. Zirkelbach D, Holm A, Künzel HM. Influence of temperature and relative humidity on the durability of mineral wool in ETICS. 10DBMC Int
Conf Durab Build Mater Components 2005.
14. Künzel HM. Austrocknung von Wandkonstruktionen mit Wärmedämm-Verbundsystemen. Bauphysik 1998;20,18–23.
15. Arizzi A, Viles H, Cultrone G. Experimental testing of the durability of lime-based mortars used for rendering historic buildings. Constr
Build Mater 2012;28,807–818.
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Full-text available
  • Nov 2023
The nearly zero energy buildings (nZEB) ideology requires foremost that the heat losses of buildings should be reduced significantly in the coming decades compared to the present levels. The efficient way to meet these requirements is to renovate apartment or public buildings with prefabricated timber frame insulation elements for the major renovation. The current study observes the hygrothermal performance of an external envelope of a 3-storey apartment building, built in Estonia of large panels of aerated autoclaved concrete (AAC) and insulated in the process of deep energy renovation with prefabricated modular elements. Long-term hygrothermal measurements were taken in the different critical spots of the external envelope and a series of combinations with modular elements were analyzed, using building performance simulation software to compare risks and the main hygrothermal properties. The analysis indicated that thermal resistance and water vapor permeability of the wind barrier layer and the presence or absence of the vapor control layer had the strongest influence on the moisture content and drying (and therefore the risk of mold growth risk) at the critical points (between the insulation layer and the wind barrier surface, and between the existing AAC wall surface and the vapor control layer) of the additional insulated exterior wall.
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... Over sixty years of use of ETICS has clearly shown that it is a good solution in various climatic conditions. The factors that may affect the deterioration of the thermal insulation properties of ETICS are known(64,(66)(67)(68)(69)(70)(71). Manufacturers are constantly developing the offered ETICS to meet customer expectations and changing technical and legal requirements(57). ...
The influence of cement on the environmental performance of construction products on the example of cementitious adhesives - External Thermal Insulation Composite Systems [ETICS] components / Wpływ cementu na charakterystykę środowiskową wyrobów budowlanych na przykładzie klejów cementowych - składników złożonych systemów izolacji cieplnej ETICS
Article
Full-text available
  • Jun 2022
The construction sector is one of the branches of the economy with a significant impact on the environment. It uses a vast amount of different raw materials. Also, it produces substantial amounts of waste and emits high amounts of greenhouse gases into the atmosphere. Reducing the energy consumption and emissivity of buildings, decarbonizing existing energy sources, optimizing the use of renewable energy, and minimizing the carbon footprint of materials and construction works are imperative to counteract climate change. It is also a minimum plan for ensuring sustainable social development. The current environmental policy in the construction sector is insufficient and it results from the legal regulations currently in force. Assessment of construction products for the seventh basic requirement, sustainable use of natural resources, is voluntary and almost always neglected. Assessment tools, such as Type III Environmental Product Declarations [EPDs] for construction products, are not widely used. Moreover, these documents are poorly recognizable among consumers, proving that there is still insufficient environmental awareness. In addition, the emerging differences in environmental impact indicators values specified in environmental declarations, resulting from using differentiated approaches in setting system boundaries or the quality of available generic data, do not support the proper development of knowledge about the impact of construction products on the environment. In this work, an analysis of the environmental impact of cement, which is a component of adhesives used in the External Thermal Insulation Composite System [ETICS], was carried out. The study on four indicators, i.e., global warming potential [GWP], soil and water acidification potential [AP], eutrophication potential [EP], and tropospheric ozone formation potential [POCP], was performed./Sektor budowlany należy do gałęzi gospodarki o istotnym wpływie na środowisko. Wykorzystuje ogromne ilości zróżnicowanych surowców, wytwarza znaczne ilości odpadów i emituje znaczne ilości gazów cieplarnianych do atmosfery. Redukcja zużycia energii i emisyjności budynków, dekarbonizacja istniejących źródeł energii oraz optymalizacja wykorzystania energii odnawialnej, a także zminimalizowanie śladu węglowego materiałów i robót budowlanych to konieczność, aby przeciwdziałać zmianom klimatycznym. To również plan minimum dla zapewnienia zrównoważonego rozwoju społecznego. Dotychczasowa polityka środowiskowa w sektorze budowlanym jest niewystarczająca a wynika to, przede wszystkim, z obecnie obowiązujących regulacji prawnych. Ocena wyrobów budowlanych w zakresie siódmego wymagania podstawowego, dotyczącego zrównoważonego wykorzystania zasobów naturalnych, jest dobrowolna, a co za tym idzie niemal zawsze pomijana. Narzędzia do oceny jakimi są m.in. deklaracje środowiskowe III typu [Type III Environmental Product Declarations-EPDs] wyrobów budowlanych nie są powszechnie stosowane. Co więcej, dokumenty te są słabo rozpoznawalne wśród konsumentów, co świadczy o ciągle niewystarczającej świadomość ekologicznej. Dodatkowo, pojawiające się różnice wartości wskaźników oddziaływania środowiskowego określanych w deklaracjach środowiskowych III typu, wynikające ze zróżnicowanego podejścia w wyznaczaniu granic systemu czy jakości dostępnych danych generycznych, nie sprzyjają prawidłowemu rozwojowi wiedzy o wpływie materiałów budowlanych na środowisko. W niniejszej pracy przeprowadzono analizę oddziaływania środowiskowego cementu będącego składnikiem zapraw klejących, stosowanych w złożonych zestawach izolacji cieplnej ETICS. Badania prowadzono w zakresie czterech wskaźników, tj. globalnego współczynnika ocieplenia [GWP], potencjału zakwaszenie gleby i wody [AP], potencjału eutrofizacji [EP] oraz potencjał tworzenia ozonu troposferycznego [POCP].
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... Only in terms of susceptibility to the growth of microorganisms, a slightly higher probability of this phenomenon was observed in the case of ETICS compared to non-insulated walls [13]. The market success of the ETICS is also because the installation itself is relatively quick, and possible runtime errors and imperfections are also well identified [14][15][16][17]. Due to changes in the formal requirements and market expectations, ETICS manufacturers systematically improve the offered solutions, according to the research published by academia [18][19][20][21][22]. ETICS is still an innovative solution. ...
Understanding Sustainability of Construction Products: Answers from Investors, Contractors, and Sellers of Building Materials
Article
Full-text available
  • Mar 2022
Preventing environmental degradation and climate changes are some of the primary challenges of our civilization. Changes to the construction sector, which consumes vast amounts of raw materials, emits significant amounts of greenhouse gas and significant amounts of waste, are very important to reduce emissions and stop negative environmental changes. Regardless of the type of goal, an essential element to achieve it is understanding the purpose and tools necessary to implement appropriate and efficient solutions. This paper presents the survey results on understanding issues related to assessing construction products, including their environmental impact. The survey was conducted among professional groups related to construction, i.e., 181 investors, 522 contractors, and 116 sellers of construction products from various regions of Poland. Questions concerning thermal insulation materials and the external thermal insulation composite system (ETICS), the most widely used solution in the EU for the improvement of thermal performance of buildings, were asked. The obtained results indicate that the knowledge of the basic requirements of construction works under the Construction Products Regulation (CPR) is not too high (the share of correct answers was respectively 33.5%, 23.2%, and 16.2% in contractors, sellers, and investors groups). Similarly, the awareness of the tested, related to the environmental burden in terms of GWP of insulation materials and components of ETICS, should be assessed (49.7% of investors, 57.1% sellers of construction products, and 76.4% contractors indicated the thermal insulation material as the ETICS component with the highest environmental impact in terms of GWP). The obtained research results indicate the need for further education for evaluating construction products and sustainability.
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... It is even used in northern Scandinavia, where winter conditions are particularly unfavourable [7]. Although the technology is carefully described and tested, it is still relatively common to encounter poor design, technological indiscipline, or the use of incorrect materials [8][9][10], which in turn increases energy consumption and reduces efficiency. ...
DEA Modelling Effectiveness of Building Envelopes
Article
Full-text available
  • Nov 2021
Today, insulated building envelopes must not only meet thermal-technical, mechanical, and economic requirements but must also be environmentally friendly. These requirements are often contradictory, and it is not clear what the effective option is for a particular case. The aim of the paper is to compare twenty different variants of building envelopes, not only in terms of thermal-technical properties but also in terms of environmental parameters and time and financial demands. The result of the paper is the determination of effective variants by a suitable mathematical method with consideration of all the above-mentioned influences.
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... In research by Langmans et al. (2017), the insulation installed in cavity walls, especially rigid-board-insulated, was highly dependent on the installation quality. Sulakatkoa et al. (2017) reported on the performance of the External Thermal Insulation Composite System with respect to installation and concluded that onsite shortcomings during the construction process led to a loss of technical performance of the product and reduced thermal efficiency. ...
Installation Quality Framework: Investment Return Approach for Energy Savings on Building Product Installation
Article
Full-text available
  • Nov 2021
Abstract A case study was conducted on 44 residential homes using both traditional house wrap and ZIP System® systems to measure the overall airtightness and compare estimated energy usages. The labor, material, and O&P costs were analyzed and used to determine the optimal choice for long term benefits in terms of cost and performance. The impact of insulation installation is considered to be a key factor in improving the strategy towards reducing energy consumption. Improved installation practices can affect the airtightness of common wall assemblies to reduce the building energy performance gap and provide insight on how to better allocate resources. A framework was developed to analyze operational costs and building energy performance to address how installation quality is a factor on the return of investment in building construction for heating and cooling systems within the thermal envelope. With this methodology, aggressive energy performance goals will be met while balancing the tradeoff between installation techniques and building systems efficiency based on the introduced Probabilistic Investment Return (PIR) metric. Keywords: Building Performance, Installation Quality, Energy Savings, Airtightness, Insulation Systems
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Effects of Hygrothermal Environment on Tensile Capacity of Adhesive-injected Anchor Bolt of ALC Panel and ETICS
Article
  • Jan 2023
The connection between the autoclaved lightweight concrete (ALC) and an external thermal insulation composite system (ETICS) is accomplished by anchors. The anchor is consisted of a connector and an anchor bolt, where the anchor bolt is an important force transmission element. Adhesive is used to install an anchor bolt, and significantly improves the anchoring force of the anchor bolt. However, the hygrothermal environment influences the adhesion of the anchor adhesive, which adversely affects the reliability and security of the ALC panel and ETICS connection. To investigate the effect of high temperature and a humid environment on the anchor bonding performance, 5 sets of durability tests were conducted. Each group of 15 specimens was tested for 0, 15, 30, 45, and 60 thermal rain cycles. The test results reveal that, as the number of cycles increased, the tensile capacity of the adhesive-injected anchor bolts decreased, and the capacity’s discount factor decreased. The discount factors of the anchor bolt tensile load capacity values after 15, 30, 45 and 60 cycles were 85.5%, 72.1%, 56.2%, and 50.4%, respectively. A prediction model was established based on the relationship between the number of thermal rain cycles and the tensile capacity. Based on the anchor bolt tensile capacity requirements, the model can calculate the number of cycles over which the adhesive-injected anchor bolts need in a hygrothermal environment must be tested, reinforced, and replaced to ensure a good connection between the ALC panel and an ETICS.
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Comparative study of Chinese, European and ISO external thermal insulation composite system (ETICS) standards and technical recommendations
Article
  • Dec 2022
External thermal insulation composite systems (ETICS) are widely used all over the world for building envelope insulation. This paper lists the representative standards for ETICS in Chinese, European and ISO technical assessment documents, and it describes the results of a comparative study on standardization, technology and engineering. First, the standards are related to the project organization mode. The Chinese and ISO standards tend to be normative and different from the standards of the European certification system. Second, the problems of leakage and degradation occur frequently in ETICS in China. It is worthwhile to learn from successful experiences in waterproofing, drainage and other measures. Third, China has made some useful technical breakthroughs in wind load resistance design and quality acceptance by means of considerable amounts research, and has an advantage in engineering practice. Lastly, the types of external insulation systems are diversified in development, in order to meet multiple requirements; it is worthwhile to learn from the European certification system. This research and the conclusions can be used as a reference for the technology, engineering and standardization of ETICS, and for understanding the essential national standards to facilitate trade between countries.
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Analysis of On-site Construction Processes for Effective External Thermal Insulation Composite System (ETICS) Installation
Article
Full-text available
  • Dec 2015
Developing a more energy efficient building stock is the focus of the European energy policies. Much of the required reduction in energy consumption needs to be achieved through the renovation of existing buildings. The External Thermal Insulation Composite System (ETICS) is widely used for the reconstruction of apartment building facades to improve thermal performance. However, the impact of the building technology and the construction process management on the quality of these reconstructed facades has received relatively little attention. In this paper, the defects in facades reconstructed using the ETICS are identified and classified, relating them to the corresponding deficiencies in the on-site technology and management. The focus is on the identification of the factors that influence facade durability in order to outline an assessment methodology for on-site monitoring.
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Towards Nearly Zero-energy Buildings through Analyzing Reasons for Degradation of Facades
Article
Full-text available
  • Dec 2014
Nearly Zero-Energy Buildings offer one way to reduce energy use in the built environment and thus contribute to mitigating global climate change. This paper is focused on analyzing the reasons for degradation of External Insulation Composite system facades in order to develop sustainable and cost-effective solutions for dwelling stock renovation. While several reasons for degradation of the facades have been studied in depth, the impact of building technology and site management have received undeservedly little attention. This paper systemizes the factors affecting facade quality and proposes a research plan for on-site surveillance in order to measure the weight of different degradation factors.
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Influence of temperature and relative humidity on the durability of mineral wool in ETICS
Article
Full-text available
When an exterior thermal insulation composite system (ETICS) is applied to an outer wall containing build in moisture, the insulating material can be subjected to an increased moisture strain during the drying-out phase. Short-term increases in moisture levels may also arise as a result of driving rain. If high temperatures occur at the same time then they may affect the durability of the insulating material. This paper aims to predict the moisture and temperature strains who occour in an ETICS under natural climatic conditions at three different locations in northern, middle and southern Europe using computational simulations. By comparing these results with a field test it is possible to determine the maximum hygrothermal loads which arise in the insulating material of an ETICS under European climate conditions. These maximum loads can serve as a basis to review the boundary conditions for durability tests of insulating materials in the laboratory.
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Inspection and diagnosis system of ETICS on walls
Article
  • Oct 2013
  • CONSTR BUILD MATER
This paper describes an expert knowledge-based system for ETICS (External Thermal Insulation Composite System) on walls, which enables facilitating and standardising inspection, diagnosis and repair of ETICS. The system includes specific tools that provide information to aid in the analysis of degraded ETICS and lead to the preparation of solid and reliable reports. Types of anomalies, their related causes, auxiliary tests to be performed in situ and repair techniques applicable to ETICS systems are listed and classified. The relation between these parametres is expressed through correlation matrices, validated and adjusted through data obtained from inspections carried out on a sample of 146 facades with ETICS cladding. The relevant descriptive information is gathered in individual files for evey anomaly, plus diagnosisaiding method, and maintenance and repair techniques. Additional statistical analysis was performed, leading to conclusions on the most sensitive aspects of this system.
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Numerical analysis of renders’ adhesion using an interface model
Article
  • Jan 2013
  • CONSTR BUILD MATER
Adhesion of mortars is a complex mechanism that is affected by several in-service factors. Numerical modeling complements adhesion lab tests because it allows a high number of case studies in a reduced period of time and with few resources. In this paper, an interface layer with a constitutive cohesive zone model is introduced to simulate the adhesion loss between mortar and substrate. A parametric analysis is performed to study the sensitivity of the relevant parameters of the model and two application examples are presented. The numerical applications show that the proposed model can reproduce in-service factors that influence the adherence.
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Statistical models applied to service life prediction of rendered façades
Article
  • Mar 2013
  • AUTOMAT CONSTR
An approach to the evaluation of the service life of rendered façades applying statistical tools is described. Using multiple linear regression analysis and artificial neural networks, mathematical models are established to estimate the degradation of this type of coating. To devise the models proposed, a sample of 100 rendered façades was subjected to meticulous field work to determine their condition. Some statistical parameters are used to evaluate the validity and efficacy of the models proposed. The service life of the sample of rendered façades is also evaluated, as estimated by the various models, and the result is expressed in histograms. The usefulness of these models to evaluate complex problems, such as the degradation phenomena of rendered façades, is thus demonstrated.
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In Situ Adherence Evaluation of Coating Materials
Article
  • May 2009
A set of results were presented and discussed regarding pull-off tests that were performed in various external and interior coatings that includes premixed one-coat colored renders, ceramic tiling with cementitious adhesives, inner multicoat site-made renders, pre-mixed gypsum plaster, waterproofing paint/mortar, and resin paint. The pull-off test or otherwise known as the tensile extraction test aims at evaluating the adherence capacity of a coating to its substrate which consists of extracting with a pull-off device a metallic piece that is previously glued to the coating with an epoxy resin. It has been found out that obtaining a uniform and wide distribution of pull-off strength is no easy task and that two ways of improving such technique can be proposed. These are the noninvasive techniques application and the systematic approach using the pull-off technique.
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Influence of admixtures on the cracking sensitivity of mortar layers applied to a mineral substrate
Article
  • Jun 2011
  • CONSTR BUILD MATER
Mortar layers used as renderings or adhesives can be exposed to conditions of temperature and humidity that can induce considerable dimensional variations. As these mortar layers are applied to an adhesive substrate, the dimensional variations are restrained and can thus produce significant tensile stress inside the mortar. If such stresses exceed the tensile strength, cracking can occur. This paper proposes a methodology for analysing the sensitivity of mortars to cracking in relation with the characteristics of the substrate. A new test method named the “de-bonded length” test was designed, developed and validated. The effect of both polymeric admixtures (type and quantity) and substrate conditions on the cracking time was analysed. The mechanical characteristics of the mortar were also determined by means of a three-point bending test. Moreover, the cracking time was analysed in regard to flexural strength, flexural modulus and flexural toughness. It follows that the cracking sensitivity depends on the flexural toughness, whatever the quantity and type of polymeric admixtures or the humidity of the substrate at the time of mortar casting.
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Experimental testing of the durability of lime-based mortars used for rendering historic buildings
Article
  • Mar 2012
  • CONSTR BUILD MATER
To find out which render mortar mix shows the best durability properties, we have designed four ageing tests that aim to simulate water movements, ice formation and salt crystallization in lime mortars exposed to an extreme, but realistic, range of temperature and humidity. It has been found that the response of individual mortar mixes differs according to the mechanism and the agent of attack. These findings suggest that in order to provide useful data both the experimental testing approach and the types of mortar tested need to be tailored for the particular circumstance in which the render will be applied.
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Evaluation of mixing and application process parameters of single-coat mortars
Article
  • May 2005
  • CEMENT CONCRETE RES
The effects of different preparation and application conditions of single-coat mortars in their characteristics as fresh and hardened products are described in this work. The parameters under consideration were mixing water, mixing and resting time of the fresh mortar. Tests were made in the fresh mortar like apparent density, amount of entrained air and water retention. Tests with the hardened mortar also included mechanical strength and capillarity evaluations. Finally, practical cases were considered and here some application parameters were studied. It was possible to conclude on some important parameters affecting both the processing and application of single-coat mortars.
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