Wood is a highly versatile renewable material (with carbon sequestering properties), that is light in weight, has good strength properties in both tension and compression while providing good rigidity and toughness, and good insulating properties (relative to typical structural materials). Engineered wood products combine the benefits of wood with engineering knowledge to create optimized structural elements. Cross-laminated timber (CLT), as one such engineered wood product, is an emerging engineering material which provides great opportunities for the building industry. While building with wood has many benefits, there are also some concerns, particularly decay. Should wood be exposed to elevated amounts of moisture, rots and moulds may damage the product or even risk the health of the occupants. As CLT panels are a relatively new engineered wood product, the moisture characteristics have yet to be properly assessed. Consequently, the amount of decay risk for CLT in building applications is unknown, and recommended protective actions during design construction and operation have yet to be determined. The goal of this research was to determine the moisture durability of CLT panels in wall assemblies and address concerns related to built-in construction moisture. The approach used to address the problem was to first determine select moisture properties of CLT panels through experimental approaches, and then use the results to calibrate a hygrothermal model to quantify the risks of wall assemblies. The wall assemblies were simulated in six different cities across Canada, representing a range of climates: Vancouver, B.C., Edmonton, A.B., Winnipeg, M.B., Ottawa, O.N., Québec City, Q.C., and St. John, New-Brunswick. The risks associated with moisture exposure during construction are also considered in the simulations. The experimental phase of the research was limited to moisture uptake tests. These tests were utilized to determine the liquid water absorption coefficient for four different types of full scale panels (2’x2’) and 12 clear wood samples. The panels were either made of 5-ply of Western-SPF, Eastern-SPF, Hemlock-Fir, or 3-ply of a generic softwood provided by a European CLT manufacturer; the clear samples were all cut from the same nominal 2x6 SPF-grade lumber. The panels were installed in a drying rack and gravimetrically tracked to assess the drying rates of the panels. Finite resources precluded more thorough material testing, but a parametric study was conducted to determine the relative impact of the missing material data on the final simulation results. In the hygrothermal simulations, four main wall assembly types were considered- those with either exterior or interior insulation, and those using either vapour permeable or impermeable air-water barriers. Various types of insulation and vapour control were also modelled. The simulations were run for a variety of interior relative humidities. The metric for comparison between the simulations was the water content of a 4mm thin layer on the extreme lamina of a CLT panel system. The results of the simulation suggest that vapour impermeable membranes, when install on dry CLT panels (less than 14% M.C.) do not pose moisture risks in any of the climates considered. However, when high levels of construction moisture is considered, only vapour permeable membranes controlled moisture risks by allowing the CLT panel to dry both to the interior and to the exterior.

In the paper, there are presented issues related to the ice rink venues. These widely known objects,all around the world,are one of the most complex types of the public buildings. It is caused mainly by the thermal conditions, which prevails in such objects but also energy demand needed for operational processes. Range of indoor temperatures may vary from -5oC in place of ice pad and close to it, up to +20oC in dressing rooms, offices or tribunes for the spectators. Like any other buildings, the same ice rink venues should meet the conditions and provide proper indoor environmental quality (IEQ) for every user of the object. It is mainly performed by the appliance of the newest technology, which is taking care and control aspects like: temperature, relative humidity, energy usage, lighting etc. In this document, there are presented 5 ice rink facilities,which were taken into account, in order to check if there are providing comfortable and proper conditions indoors. All the investigated halls were in the City of Stockholm. In order to obtain require data, some professional tools were used including infrared camera and moisture meter. The registered data was including the average temperature of the indoor air and level of relative humidity. Based on this data, the dew point temperature has been calculated. Another aspect of the work was carrying out simulations of the typical ice rink wall construction and finding the best possible placement for the vapour barrier. In these case, the simulation had been performed in the different cities located in Sweden. Function of this layer is mainly to inhibit the migration of the water vapor and to protect the thermal insulation layer from dampness. However, installed in wrong place in the wall composition may give rise to serious problems related to moisture and humidity. By using WUFI software, it was possible to present hygrothermal conditions like: relative humidity, dew point temperature and water content of the individual component of designed wallin relation to different placement of damp proofing material.

Många byggnader är idag fuktskadade. Fuktskador uppstår på så väl nya som gamla byggnader. Idag provtrycker man hus för att få ett värde på dess täthet, men många hus som klarar täthetskraven drabbas ändå av fuktskador. Detta beror på att otätheterna är lokala på en eller flera delar av klimatskalet bortsett från otätheter vid anslutningar.   En studie har gjorts på två väggtyper; en standardvägg och en passivhusvägg. Denna undersökning har begränsats till väggar för småhus. Undersökningen syftar till att ta fram vart gränserna går innan mögeltillväxt påvisas för olika håldiametrar i plastfolien. Jämförelse gjordes för dessa väggkonstruktioner i städerna Kiruna, Stockholm och Lund. Simulering av konstruktionerna i de olika städerna gjordes i programmet WUFI Pro 5,0 med en 5-årsperiod där resultaten sedan analyserats i WUFI-Bio 3,1 RC för riskbedömning av mikrobiell tillväxt. Resultat åskådliggör att konstruktioner med tjockare isolering belägna längre upp i landet lättare kan råka ut för skador orsakade av fukt. / Many buildings today are moisture damaged. Moisture damage occurs to new as well as old buildings. Nowadays we test the dense of the building with measurement of the air flow under pressure, but still many of these building structures that meet the dense requirements are still affected by dampness. This is because the leaking points are situated at one or other parts of the building shell other than at the connections.A study has been made on two wall types: a standard wall and a passive house wall. This investigation has been confined to walls of houses. The study aims to develop each boundaries before mold growth demonstrated for different hole diameters in plastic foil. Comparison was made for these wall structures in the cities Kiruna, Stockholm and Lund.The comparison of the wall structures in the different towns was done with a simulation program WUFI Pro 5.0 for a 5-year period. Results were then analyzed in WUFI Bio 3.1 RC, program for risk assessment of microbial growth.Results illustrate that structures with thicker insulation located further up in the country can more easily encounter damage caused by moisture.

Previous studies on the typical Icelandic external wall have shown thatcondensation occurs at the interior surface of the concrete and field inspectionshave supported this conclusion. The primary objective ofthis study is to analyse the hygrothermal behaviour of the typical Icelandicwall and evaluate the mould risk at the interior surface of theconcrete.A comparative study is performed to compare the hygrothermalperformance and mould growth risk of two concrete outer wall structureswith interior and exterior insulation, by performing a parametricstudy using the simulation program WUFI® Pro.Additional parametric studies are performed in order to analyse theeffect of various material properties of the Icelandic building materialson the hygrothermal behaviour of the wall. This part also utilizedWUFI® Pro.To investigate the thermal bridge of the Icelandic wall, simulationswere conducted with the COMSOL Multiphysics software to evaluatethe linear thermal bridge and the risk of condensation at the joint.Lastly, an experiment was set up at the Innovation Center Iceland tomodel the interior insulated wall-slab section. The experimental setupwas completed during this time but the results will be analysedfurther after the thesis work.The results from this study indicate that the typical Icelandic wall ismore sensitive to rain than to interior moisture load and that no condensationoccurs within the wall structure. As concrete is inorganic,the risk of mould growth in the wall structure is limited, however,with increased driving rain load the mould risk increases. The resultsalso revealed that the moisture content of the interior insulated wallwas a great deal higher compared to the exterior insulated wall. Furthermore,the humidity level at the interior surface of the concrete inthe interior insulated wall exceeded the recommended critical humiditylevel based on general suggestions. Finally, results indicated thatusing a more dense concrete resulted in higher relative humidity at theinterior surface but a lower total water content of the wall.

Att bygga beständiga konstruktioner är ett centralt begrepp inom byggsektorn. Byggsektorn skall möta dagens behov av konstruktioner, och samtidigt finns ett behov av att komma fram med nya tekniska lösningar. Samverkanskonstruktioner är ett konstruktionssätt som medför en rad fördelar för projektering, utförande och förvaltning. Problemet med att sträva efter nya och behovsanpassade tekniska lösningar som exempelvis samverkanskonstruktioner är att metoderna inte är lika beprövade som traditionella konstruktionstyper. Detta medför att samverkanskonstruktioner utformning kan orsaka oanade konsekvenser för material i konstruktionen. I detta arbete har en samverkanskonstruktion i form av en gång- och cykelbro undersökts. Bron består av samverkande betong och trä. Intresset för denna typ av samverkan finns då den har en lägre egenvikt jämfört med rena betongbroar, men mindre underhåll av gångbanan jämfört med träbroar. Till skillnad från betong- och träbroar föreligger det i Sverige en brist på erfarenhet av denna samverkanskonstruktion. Rapporten har fokus på fuktvandring och fukt i trä med avseende på teknisk livslängd. För att utreda eventuella risker med avseende på fuktvandringar och fukt, utfördes fältmätning och simulering i programmet WUFI Pro 6.0 av en referenskonstruktion belägen i Göteborg.Arbetet gav indikationer på att konstruktionslösningen betong och trä går att genomföra, dock med rekommenderad försiktighet vid utformning. Hur förhöjda fuktkvoter påverkar den tekniska livslängden kunde ej fastställas då detta beror på flertalet faktorer. För fuktvandringen i konstruktionen hittades inget samband som visade något entydigt resultat, då simulering visade en fuktvandring från betong till trä medan fältmätning inte visade något sådant. Däremot visade både simulering och fältmätning att ytfuktkvoten i träet vid fältmätningsdatum var under uttorkning. Arbetets slutsats var att referensobjektets tekniska livslängd sannolikt inte kommer påverkas nämnvärt av fuktinnehållet i trädetaljerna utan kommer att avgöras av tillverkarens beräknade tekniska livslängd för träet. / Durable constructions is a key concept in the modern building sector. At the same time constructions needs to meet the demands of modern building techniques. This means that the building sector needs to develop new technical solutions. Composite constructions is a technical solution that simplifies project planning, production and facility management. The problem with striving for new technical solutions like composite constructions is that the methods are not as proven as traditional technical solutions. This could bring unexpected consequences to the different materials in the construction.This report aims to investigate a composite construction in the form of a bicycle and pedestrian bridge. The materials used in the composite construction is concrete and wood that gives the bridge a lower self-weight compared to concrete bridges, but requires less maintenance of the roadway than a wooden bridge. The reason for the investigation is the lack of experience in Sweden of this construction type. The report focuses on moist transport and moisture in wood with regard of technical life length. To investigate possible hazards, a field investigation and a computer simulation was made of a reference construction situated in Gothenburg. The field investigation consisted of a resistance measurement of wooden details in the composite construction. The simulation was made with the aid of the program WUFI Pro 6.0. The report indicated that the technical solution with concrete and wood is a doable construction type, but caution must be regarded in the design of the bridge. The moisture transport could not be determined due to different results in the simulation and field measurement. The report concluded that the technical life length is not going to be compromised due to the moisture content in wooden details.

Idag ligger fokus på energieffektivisering av byggnader. I och med detta ligger tung vikt på fuktsäkerhetsprojektering i konstruktioner som i sin tur måste vara lufttäta och diffusionstäta. Kombinationen av svenska vinterperioder och övertrycket som uppstår inomhus medför att taken utsätts för stora påfrestningar. Luften inomhus innehåller alltid mer fukt än luften utomhus. Då fukt alltid strävar efter att jämna ut sig går den varma och fuktiga inomhusluften till utrymmen med lägre fukthalt eller lägre lufttryck. Det är bland annat av dessa anledningar man använder ångspärr i ytterväggar och takkonstruktioner. Syftet med detta projekt är att genomföra en fuktteknisk bedömning för takkonstruktioner uppbyggda av TRP plåt, PIR isolering utan plastfolie. Anledningen till att bygga tak utan plastfolie är att sätta fuktfrågorna i fokus vid nybyggnadsprojekt samt att eftersträva skapandet av fuktsäkra och sunda konstruktioner. För att analysera takkonstruktionen samt genomföra fukttekniska bedömningar har simuleringar av konstruktionen under olika förutsättningar i WUFI Pro 5.1. genomförts. Därefter har resultatet analyserats ur diffusions- och konvektionssynpunkt. Resultaten visar inga större skillnader ur diffusionssynpunkt. Dock är skillnaderna mer uppenbara ur konvektionssynpunkt. Fuktmängden i konstruktionen utan plastfolie var betydligt större än konstruktion med plastfolie. Resultaten visar på att luftläckaget och fuktmängden har ett proportionellt förhållande med luftspaltbredden som bildas mellan PIR isoleringselementen. Detta gäller om ingen plastfolie används i konstruktionen. Slutsatsen är att det råder en större risk för luftläckage hos takkonstruktionen utan plastfolie på grund av otätheter i skarvar och spalter. För att få en fuktsäker och sund konstruktion rekommenderar författarna att plastfolie används. / Nowadays there is a high focus on energy efficiency of buildings. Therefore, a lot of resources are dedicated to moisture management in order to ensure that constructions stay airproof and diffused.  The combination of Swedish winter periods and the overpressure that occurs indoors means that the ceilings are subjected to the great stress. Indoor air contains more moisture than the air outdoors. As moisture is always striving to even out, the hot and humid indoor air moves to spaces with lower moisture content or lower air pressure. It is partly for these reasons why it is necessary to use a vapor barrier in the outer wall and roof construction. The purpose of building roofs without plastic foil is to put moisture issues in focus for new construction projects, but also, seek to create moisture proof and healthy construction designs. Further the goal of this project is to conduct a moisture technical assessment of roof structures built by TRP plate and PIR insulation without plastic film. Additionally, investigate if PIR-insulation can act as diffusion and convection protection. In order to analyze the roof structure and conduct moisture technical assessments, the design has been simulated using WUFI Pro 5.1 during different conditions. The result has then been analyzed from diffusion and convection perspectives. The results showed no major differences when compared from diffusion point of view. However, the differences are more obvious from convection perspective. The amount of moisture in the construction without plastic foil was considerably larger than the construction with a plastic foil. The results also showed that the air leakage and moisture amount has proportional ratio to the air gap width between the PIR-insulation elements. This is the case if no plastic foil used in the construction. The conclusion is that there is a greater risk of air leakage in the roof construction without the plastic foil because of leaks in the joins or gaps. For a moisture-proof and healthy design, the authors recommend that a plastic foil should be used.

To save energy it’s popular to build houses with low energy loss. In these houses the walls are keeping a lower temperature in the external side which leads to a higher relative humidity. In addition more material, such as wood studs, are used which means that there is more moisture to dry. More moisture in combination with higher relative humidity may pose a higher risk of microbial growth. The purpose of this study was to investigate what is a reasonable moisture content in wood studs in four different well-insulated exterior walls. It has also been investigated how moisture rearrangements effect the exterior walls. The software Wufi2D, which does moisture-simulations, was used to collect data. The results have been analyzed in Wufi Bio which showed that the moisture content should be somewhere between 12.5 to 18.5%, depending on how the wall is built. The conclusions are that windbreaks vapor resistivity is essential for what is a reasonable built in moisture content in the wood studs. Depending on the materials that are used, it´s important to consider how much moisture the wall construction contains.

Trenden i byggbranschen är att efterfrågan på täta, energisnåla byggnader ökar. Passivhus och andra lågenergikonstruktioner blir vanligare och vanligare. Riskerna med att bygga in organiskt material som trä i dessa konstruktioner har fått branschen att börja titta på alternativa material. Lättbetong är ett material som både har bärande och isolerande egenskaper. Dessutom är det inte organiskt vilket gör det okänsligt för mikrobiell påväxt. Det som är intressant med lättbetong, ur fuktsynpunkt, är att materialet levereras från tillverkare med en stor mängd byggfukt. Våren 2014 färdigställde Bollnäs Bostäder passivhus- projektet Sundsbro i Bollnäs, där lättbetong ingår i utfackningsväggarna. Sett inifrån består väggen av ett tunt lager kc-puts, lättbetong, cellplast, mineralull, kc-baserad grovputs och ytputs. I detta arbete användes projektet i Bollnäs som referensobjekt och en risk- och känslighetsanalys av väggkonstruktionen utfördes. Arbetet utreder risken för fuktrelaterade problem med väggen vid de extra uttorkningsinsatser som vidtogs i referensobjektet och vid normala uttorkningsbetingelser. Vidare utreds vilka parametrar som är viktiga för väggens fuktfunktion och vad man behöver tänka på när man projekterar och bygger i lättbetong. Arbetet har genomförts i samarbete med AK-Konsult Indoor Air AB och deras senior konsult Anders Kumlin. Fuktberäkningsprogrammet WUFI Pro 5.3 har använts för simuleringar. Beräkningarna gjordes endimensionellt på väggkonstruktionen. Resultaten med den ökade uttorkning som utfördes i referensobjektet visar inget högre fuktinnehåll längst ut i väggen på grund av byggfukt från lättbetongen som vandrar utåt. Farhågan var att så skulle kunna ske och att det skulle kunna leda till mögelproblem. Däremot visar resultaten att bygg-fukt från putsen kan fukta upp mineralullen. Det finns dock inga kända skadefall av detta slag och därför dras ändå slutsatsen att konstruktionen är riskfri. Tack vare en förutseende fukt-projektering och väl utförd uttorkning eliminerades risken för mögel. Hade inte dessa åtgärder vidtagits så visar resultaten att en liten mängd byggfukt hade kunnat vandra utåt och kondensera i mineralullen under första vintern. Då hade det funnits risk för mikrobiell påväxt. Detta visar att det är av största vikt att utföra en noggrann fuktprojektering vid byggnation av välisolerade hus i allmänhet och i synnerhet när lättbetong används. Lyckligtvis gjordes detta på ett bra sätt i referensprojektet. Känslighetsanalysen visar att isoleringens diffusionstäthet är avgörande för hur stor del av bygg-fukten som kan vandra utåt och därmed hur stor risken för problem blir. Lägre täthet ger större risk och högre täthet reducerar risken. Resultaten visar också att det är viktigt att inte montera täta skikt på insidan för tidigt. Den allmänna rekommendationen från leverantör är att lättbetongen skall torkas till 15 % fuktkvot på 50 millimeters djup innan målning och tapetsering på insida vägg får ske. Studien visar att detta är ett för högt fukttillstånd om det skikt som appliceras på insida vägg är tätt. Lättbetongen bör torkas till 5 % på 50 millimeters djup innan helt täta skikt kan monteras utan mögelrisk. / The trend in the construction industry is that the demand for tight, energy-saving buildings is rising. Passive houses and low energy constructions are becoming more and more common. The risk with using organic material in this type of constructions has made the industry look at alternative materials. Aerated concrete is a material that has both load-bearing and insulating properties. In addition to that it is not organic, which makes it insensitive to microbial growth. What is interesting with aerated concrete, from a moisture point of view, is that the material is delivered from the producer with a large amount of construction moisture. In the spring of 2014, the passive-house project Sundsbro in Bollnäs with aerated concrete in the wall construction, was finished by Bollnäs Bostäder. In this study the project in Bollnäs was used as reference object and a risk- and sensitivity analysis was made. The study examines the risk of moisture related problems with the wall construction during normal dehydration conditions and after the increased dehydration efforts that were taken in the reference project. The study also examines which parameters are important for the moisture function of the wall construction and what you need to think about when you project and build with aerated concrete. The job has been done in cooperation with AK-Konsult Indoor Air AB and their senior consultant Anders Kumlin. The moisture calculation program WUFI Pro 5.3 has been used for simulations. The results with the increased dehydration that was used in the reference project show no increased moisture content in the outer parts of the construction due to construction moisture from the concrete that wanders outwards. The concern was that so could happen and that it would lead to mould problems. However the results show that construction moisture from the exterior plaster can moisten the mineral wool. There are no known damage cases of this sort and therefore the conclusion is that the construction is free of risk. Thanks to a foreseeing moisture projection and a well performed dehydration the risk of mould was eliminated. If these measures would not have been taken, the results show that a small amount of construction moisture could have wandered outwards and condensed inside the mineral wool during the first winter. Then there would have been a risk of microbial growth. This shows that it is very important to carry out a detailed moisture projection when constructing well insulated houses in general and when using aerated concrete in particular. Fortunately this was properly done in the reference project. The sensitivity analysis shows that the diffusion resistance of the insulation decides how much of the construction moisture that can wander outwards and consequently the size of the problem risk. Results also show that it is crucial not to apply sealing layers on the inside of the wall too early. The general recommendation from the supplier is that the aerated concrete should be dried to 15 % moisture ratio on 50 millimeter depth before painting and paper hanging on the interior surface of the wall can be done. The study shows that the concrete still is too damp at that stage if the layer applied on the inside of the wall is impermeable. The concrete should be dried down to 5 % moisture ratio before sealing layers can be applied without mould risk.

This thesis covers calculations of the equivalent measuring depth in the joint concrete between hollow-core slabs performed using the calculation and simulation program WUFI Pro. The calculations are based on input data from field measurements performed by Polygon|AK in Uppsala. Input from the company has been combined with a moisture profile from the calculation program Torka S to construct a basic model in WUFI. Simulations have been made based on the basic model with constant water-cement ratio in joint concrete, three varying parameters in terms of relative humidity in spackle, leveling height for spackle and vapor resistance in carpets. In order to get a broader result basis, 18 different typical cases for further analysis have been studied.  The calculation results indicate that the industry standard according to RBK, which states the equivalent measuring depth to 50 % of the hollow-core slabs joint height, does not correspond to the calculation basis for this work. The result of this work indicates that the actual equivalent measuring depth is about 15-18 % of the height of the joint, depending on the selected parameters. The difference between the industry standard and the result of this work can be explained by the fact that in the previous calculations of the equivalent measuring depth assumes a completely dense surface layer and no drying downwards and moisture from glue has not been taken into account. The assumption that the water contained in the cross section does not dry out and only redistributes leads to results that do not correspond to today's real conditions in terms of more diffusion-open carpets, moisture from carpet glue and different moisture conditions in spackle.

The construction industry stands in front of a challenge to decrease theirclimate footprint in order to build more environmentally friendly. There iscurrently a desire to investigate the possibility to use wood to a largerextent. Compared to the more conventional building materials, wood has ahigher risk of being damaged due to moisture, which can lead to moldgrowth. In Boverket’s Building Regulations its stated that buildings are tobe designed to ensure that conditions detrimental to human health areavoided.The report has investigated the moisture-technical possibilities of usingcross-laminated timber, CLT, instead of concrete in large-scaleconstructions.Moisture simulations of four different structural parts has been conductedwith concrete and CLT as the supporting structure. The simulations showedthat there is no theoretical risk of moisture damage. The study shows that itis possible to change the materials, but that the right conditions arerequired to protect and prevent the occurrence of moisture damages duringproduction. At present, there is no possibility to guarantee that moisturedamages on CLT is avoided without the use of weather protection. A wellworkedmoisture safety plan is essential for a moisture-proof productionphase, the use of industry standard ByggaF can be a valuable and vital toolto ensure it.