| 1. |
- Buck, Dietrich, 1990-, et al.
(author)
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Impregnation of Wood / End Grain Treatment
- 2021
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Conference paper (other academic/artistic)abstract
- This research presents the findings of a study conducted by Luleå University of Technology (LTU) and Lund University (LTH) on the effect of edge treatment on the end grain of cross-laminated timber (CLT) elements. The objective of the study was to identify whether edge treatment influences the moisture performance and mould risk of CLT.The investigation was conducted through controlled laboratory studies, utilising standardised procedures. Specifically, the end grain of the CLT specimens was exposed to moisture by placing them in contact with a free water surface for 96 hours. Following this exposure, the specimens were dried under controlled conditions. X-ray computed tomography (CT) scanning was used to estimate the moisture content of the specimens and provide detailed spatial information about the moisture distribution within the wood.To further evaluate the effectiveness of edge treatment, the experimental moisture content assessments were compared to values by WUFI simulations. Additionally, annual data for the simulations were conducted using climate data from three different locations: Lund, Stockholm, and Borlänge. These simulations assessed the theoretical impact of edge treatment on mould risk under different climatic conditions.Results revealed that edge treatment has potential to reduce moisture content and mitigate mould risk in CLT elements. Experimentally assessed moisture content values were consistently lower in edge-treated specimens compared to untreated specimens. The calculations and simulations supported these findings, showing a distinct reduction in moisture accumulation and mould risk in edge-treated CLT elements.This study provides insights into the effect of edge treatment on the moisture performance and mould risk in CLT elements. The findings suggest that implementing appropriate edge treatment techniques can enhance the durability of CLT structures, particularly for worksites in regions where climatic conditions fluctuate over the course of construction. Further research and testing are warranted to explore additional factors influencing the effectiveness of edge treatment in CLT applications.
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| 2. |
- Buck, Dietrich, et al.
(author)
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Moisture- and mould-resistance : modelling of edge-sealed cross-laminated timber using multi-modal assessment leveraged by X-ray computed tomography
- 2023
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In: Materials and Design. - 0264-1275. ; 230
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Journal article (peer-reviewed)abstract
- Edge-sealing, which involves treating the edges of wood products, improves water resistance. This study investigated the feasibility of edge-sealed cross-laminated timber (CLT) panels to reduce capillary water uptake, thereby resisting mould formation. The water and vapour permeabilities of ten characteristically different single-layer sealant coating systems were systematically determined. X-ray computed tomography (CT) scanning methodology was used to enhance detection of material characteristics beyond the standard coating permeability assessment. Moisture content was observed to change during the specimens’ absorption and desorption depending on the sealant system applied. The results revealed different characteristics of coatings during the water absorption and desorption stages. Findings from this study were used to develop recommendations regarding the water resistance of coating systems, curing time, susceptibility to mould formation, and industrial applicability. Results suggest that edge-sealed CLT could minimise the risk of mould formation, which can occur at worksites with minimal weather protection. The method developed in this study provides a basis to evaluate new coating systems and determine which use case is the best for a particular coating type. This study also incorporates insights from industry to identify future research orientations, which may pave the way for new designs and assessment techniques.
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| 3. |
- Buck, Dietrich, 1990-, et al.
(author)
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Moisture- and mould-resistance: multi-modal modelling leveraging X-ray tomography in edge-sealed cross-laminated timber
- 2023
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In: Materials & design. - : Elsevier. - 0264-1275 .- 1873-4197. ; 230
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Journal article (peer-reviewed)abstract
- Edge-sealing, which involves treating the edges of wood products, improves water resistance. This study investigated the feasibility of edge-sealed cross-laminated timber (CLT) panels to reduce capillary water uptake, thereby resisting mould formation. The water and vapour permeabilities of ten characteristically different single-layer sealant coating systems were systematically determined. Multi-modal assessment leveraged by computed tomography (CT) scanning methodology was used to enhance detection of material characteristics beyond the standard coating permeability assessment. Moisture content was observed to change during the specimens’ absorption and desorption depending on the sealant system applied. The results revealed different characteristics of coatings during the water absorption and desorption stages. Findings from this study were used to develop recommendations regarding the water resistance of coating systems, curing time, susceptibility to mould formation, and industrial applicability. Results suggest that edge-sealed CLT could minimise the risk of mould formation, which can occur at worksites with minimal weather protection. The method developed in this study provides a basis to evaluate new coating systems and determine which use case is the best for a particular coating type. This study also incorporates insights from industry to identify future research orientations, which may pave the way for new designs and assessment techniques.
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| 4. |
- Claesson, Johan, et al.
(author)
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Benefits of Investigating the Thermal Component for Moisture Safety in Ventilated Attics
- 2020
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In: 12th Nordic Symposium on Building Physics (NSB 2020). - : EDP Sciences. - 2555-0403. ; 172
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Conference paper (peer-reviewed)abstract
- Cold ventilated attics often have mould problems in Sweden. This is valid both for old and sometimes newly built attics. Increased insulation on the attic floor is assumed to increase the problem. To investigate this, numerical 1D models like WUFI or WUFI+ are typically used. These models give results but the physical processes are not so transparent for the user due to the complex numerical techniques involved and takes a long time to simulate. The problem is mainly related to the temperature in the attic, the ventilation rate and possible of leaks from the living space. All exposed surfaces in the attic will buffer moisture variations. But if this buffering is neglected and the leakage is treated as a constant the moisture content in the attic is only dependent on the ventilation with outside air and the assumed leakage. This would make a pure thermal investigation meaningful. An analytical model for the thermal problem was developed that took into account radiation between the interior surfaces and the different boundary conditions at the outside and inside surfaces. Using this model a parameter study of exterior roofing insulation was done using a moisture transport model that only took into account convection exchange. The results were compared with WUFI Pro and WUFI+ simulations which included the moisture exchange between air and internal surfaces. The comparison showed that the pure thermal model gave, as expected, larger variations in relative humidity, but that the results were qualitatively very similar. This indicates that analytical solutions of thermal problems can be used as a base in qualitative investigations of certain combined heat and moisture problems.
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| 5. |
- Hansen, Thor, et al.
(author)
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Investigation of the Mould Resistance Design (MRD) model for mould growth in attics
- 2020
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In: 12th Nordic Symposium on Building Physics (NSB 2020). - : EDP Sciences. - 2555-0403. ; 172
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Conference paper (peer-reviewed)abstract
- Based on measurements of mould in 17 attics in the north of Sweden, 3 were chosen as a tentative validation of the MRD-model (Mould Resistance Design) for long periods of time (1961-2012). Comparing the measurements and the results from the simulations showed great differences regarding the mould growth depending on the simplifications used in the model. How the leakage was simulated and where the moisture from the leakage was placed in the construction were the most important factors. The study could not validate the MRD model as such, but it was clear that the simulations with relatively small adjustments could give realistic data.
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| 6. |
- Mattsson, Christian, et al.
(author)
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Cost performance analysis of water damages for sustainable prevention measures
- 2022
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In: Indoor Air 2022. ; 17th
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Conference paper (peer-reviewed)abstract
- Water damage in homes and buildings can cause moisture problems such as mold growth and negative health effects for residents. The water damage from building services not only affects the indoor environment but leads to costs for society both in Sweden and other countries. This paper aims to make a cost analysis to attain an estimate of the cost of water damages to society. The analysis is based on insurance reimbursements, deductibles, depreciation, and age reduction costs for water damages in both residential and non-residential buildings. The results showed that the estimated cost in Sweden amounts to 955 M€ annually. The economic impact that originates from water damages is shown to be immense meaning, there is economic potential for sustainable prevention measures to reduce the amount and cost of water damages.
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| 7. |
- Mattsson, Christian, et al.
(author)
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Examination of Water Damage Statistics in the Nordic Countries to Identify and Suggest Preventive Cost-effective and Sustainable Measures during the Maintenance and Operation Phase
- 2023
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Conference paper (peer-reviewed)abstract
- Water damage in the indoor environment is a rising issue within Nordic countries with about 90 000 cases in appx. 6.5 millioninsurance is reported annually in Sweden, and corresponding numbers are in Denmark and Norway. The question thenbecomes what type of measures residents, building managers, and insurance companies can take in the maintenance andoperation phase to decrease the impact of the water damage. Another question is how the effects, cost, and extent of the waterdamage are affected if the measures were executed in this phase as preventive measures. This was done by selecting actionsand measures that could reduce the impact and cost of water damage, examining the action and measures, and finally analyzingthe payback time of the investment of the actions and measures. The study shows average payback times for the actions andmeasures studied, for passive investments between 10 months and 8 years, and longer for investments that actively shutting offthe water in case of a leakage, between 18 years and 30 years on average. The study demonstrates the potential benefit ofimplementing cost-effective measures, such as waterproof underlays beneath the fridge and the dishwasher. This suggests thatintroducing effective measures in the maintenance and operation phase will reduce the effect of water damage and also reducethe effect of water damage in a large portion of the existing buildings and therefore also reduce the immense amount ofresources annually spent on water damage (approximately 1 billion USD each year in Sweden).
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| 8. |
- Mattsson, Christian, et al.
(author)
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Similarities, differences, and tendencies of water damage in the Nordic countries
- 2023
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Conference paper (peer-reviewed)abstract
- This extended abstract compiles statistics and information regarding the process of gathering water damage statistics. A questionnaire wasused to determine similarities, differences, and tendencies in the water damage statistics, in the Nordic countries Sweden, Norway, Denmark,Finland and Iceland. The study aimed to answer what lessons were learned and what knowledge could be shared between the Nordiccountries to reduce water damage. Several suggestions and tendencies between the counties are introduced and what obstacles are hinderinga deepened cooperation, based on the answers from the statistic-gathering companies acting in the five countries, such as insurance- andindustry organizations. A first step should be to increase the number of buildings included in the statistics, such as multi-family and public.
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| 9. |
- Mattsson, Christian, et al.
(author)
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Water damages in HVAC, tap water and sewage systems in cold climates
- 2021
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In: Cold Climate HVAC & Energy 2021. - : EDP Sciences. - 2555-0403. ; 246
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Conference paper (peer-reviewed)abstract
- Water damages in buildings in the Nordic countries results in costs amounting to several billion Euros each year as well as a great deal of unpleasantness. The vast majority of the water damages cost in Sweden is caused by leaks from buildings services in the form of piping such as tap water, sewage, drainage and heating, as well as through insufficiently waterproof layers in wet rooms. The economic potential for making measures to prevent water damages on building services and wet rooms is enormous and savings could be used for other sustainability measures in the built environment. The aim of this paper is to review statistics of damages caused in cold outdoor climates. This is done by an analyse of empirical damage statistics by a literature review of both scientific literature and in retrievable cases from practical experience. The result will be a help to focus on the right damage types in colder climate and will make a foundation for future research on how to prevent water damages. The cold climate in the Nordic countries seems to be a factor for the number of water damages due to freezing that are described in the statistics and it could be established that the impact of the climate should be considered and that it need to be constructed and designed for in a larger extent.
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| 10. |
- Nik, Vahid, 1979-, et al.
(author)
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Klimatdata och klimatfiler för övertemperatursimuleringar i byggnader : en kunskapssammanställning
- 2022
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Reports (other academic/artistic)abstract
- Denna kunskapssammanställning om klimatdata och klimatfiler kan ge en bred och korrekt förståelse om var det finns kunskap och vilka utvecklingsbehov som behöverstödjas, vilka som agerar inom området och vilka regler och standarder som tillämpas.För att klara klimatförändringar har det stora fokuset inom byggsektorn (och många andra sektorer) hittills varit att ”lindra effekterna av klimatförändringen”. Detta samtidigt som det är nödvändigt med förberedelser för klimatförändringar, eftersom de sker och påverkar alla människor. Därför behövs större uppmärksamhet på ”klimatförändringsanpassning” genom att öka kunskapen inom byggsektorn, utveckla och testa metoder och syntetisera lättanvända uppsättningar av klimatdata för användarna.I många länder måste användarna köpa väderdata, medan det i andra länder finns uppsättningar av väderdata som är offentliga. Det finnas flera tillvägagångssätt för att ta fram indata (klimatfiler för framtiden) till den stora användningen som kan förutses. Allt kräver investeringar i att skapa kunskap och underlag/data som kan delas med användarna. Felaktig användning av klimatfiler för framtiden kan leda till mycket dyra ekonomiska konsekvenser. Analysers rumsliga och tidsmässiga upplösningar spelar en viktig roll för kraven på kvalitet på klimatfiler för framtidens väder.Mikroklimat påverkar energi- och fuktprestandan hos byggnader (och energisystem) men försummas av de flesta tillgängliga tillvägagångssätten. Detta samtidigt som effekter av extrema klimathändelser kan förändras avsevärt i urban/mikroskala. Att ta hänsyn till mikroklimat kommer att öka kostnaden för analyser avsevärt och det är inte möjligt i alla lägen. Därför behöver prioriteringar göras av kvalificerade beslutsfattare.Osäkerhet finns i alla indata som används i olika analyser av energianvändning och inomhusklimat. När beräkningar och simuleringar görs, kan säkerhetsmarginaler anpassas på olika sätt. Klimatfiler för framtiden kan ha säkerhetsmarginal, men frågan ärom det ska vara för en kort, lång eller mycket lång period.I dagens bostadsprojekt är det mycket ovanligt med komfortkyla. Kommer det att vara annorlunda om 10–15 år? Behöver nya byggnader förberedas för komplettering med komfortkyla? Möjliga konsekvenser och hur osäkerhet ska hanteras samtsäkerhetsmarginaler användas behöver utredas vidare.Det finns tre stora luckor i nuläget för byggbranschen (och anläggningsarbeten)Brist på korrekta väderdata/klimatfiler för framtiden, som lätt kan användas av alla intressenter.Brist på nya/uppdaterade/verifierade tillvägagångssätt som korrekt tar hänsyn till extrema väderhändelser och osäkerheter om klimatet.Bristande kunskap hos ingenjörer, intressenter, ansvariga offentliga sektorer och även forskare om konsekvensanalys av klimatförändringar.Med tanke på de senaste framstegen inom området för modellering av klimatförändringar och det framgångsrika forskningsarbetet med att koppla klimatmodeller till tekniska modeller, borde det finnas stora möjligheter att ta itu med frågeställningarna. Det krävs att tydliga mål sätts upp och att åtgärder vidtas.
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