This study aimed to experimentally evaluate the properties as sound absorbers of two modular green roof systems commonly used in Brazil: the Alveolar simple and the modular Hexa. This study emerged from the unification of two aggravating problems, being the environment degradation and the environmental noise, given the records that vegetated roofs generally have several environmental benefits, including acoustic. The two systems were evaluated with the same substratum, but with different features and using distinct plants and assembly modes, that is, grass on the Alveolar system and plants of the sedum genus on the Hexa modular system. Measuring experiments of sound absortion have been made for each of the systems, consisting of two measurings with different substratum thickness and one measuring of the systems with sedum plants. The chosen experimental procedure was the method of reverberation chamber in a diffuse sound field. It was found that substrata of all the combinations of investigated samples have interesting absorption properties, due their porosity. The maximum sound absorption coefficient α of the Alveolar system with 2.5cm thick substratum was 1.0 at 1kHz, and the lower frequency coefficient are close to 0.20. The Alveolar system with 4 cm of substratum and the Hexa modular system with sedum plants were those which had, in general, higher values for α in all frequency bands, as well as showing the highest NRC values, in other words: values of 0.80 and 0.81 respectively. The maximum α in the Alveolar system with a layer of 4 cm thick substratum reached the value of 0.89 at frequencies of 1 kHz, 2 kHz and 2.5 kHz, and at the low frequencies from 100 Hz to 200 Hz the sample reached α values between 0.25 and 0.32; whereas the Hexa modular system with a 6cm substratum plus sedum the α values were 0.94 at a frequency of 800Hz, and between 0.16 and 0.26 at low frequencies. The 4cm thick Alveolar system with grass was the system which had higher α values in the frequencies of 100Hz and 200Hz, between 0.31 and 0.38, therefore being most efficient for traffic noise absorption. In general, the absorption coefficients of all samples doubled the value at the range of 250Hz, in comparison to the 200Hz frequency. The obtained results show a high absorption coefficient for such systems, which indicates that using green roofs can be na effective alternative of urban noise control. / Este estudo teve como objetivo principal avaliar experimentalmente as propriedades como absorvedores sonoros de dois sistemas modulares de telhados verdes comumente utilizados no Brasil: alveolar simples e hexa. Este eclodiu da unificação de dois problemas agravantes, sendo a degradação do meio ambiente e ruído ambiental, partindo-se dos registros que telhados vegetados de forma geral possuem vários benefícios ambientais, inclusive acústicos. Foram analisados os dois sistemas com a mesma composição de substrato, porém com particularidades no esquema de montagem e plantas diferenciadas, isto é, grama no sistema alveolar e planta do tipo sedum no sistema hexa. Foram realizados experimentos de medição de absorção sonora de cada um dos sistemas, sendo duas medições considerando espessuras diferenciadas de substrato e uma medição do conjunto com planta. O procedimento experimental foi o método da câmara reverberante em campo difuso. Verificou-se que os substratos das amostras de todas as combinações investigadas possuem interessantes propriedades de absorção, por serem altamente porosos. O coeficiente de absorção sonoro (α) máximo do sistema alveolar com 2,5cm de substrato foi de 1,0 em 1 kHz, e nas baixas frequências tem coeficientes próximos de 0,20. Já o sistema alveolar com 4 cm de substrato e o sistema hexa com sedum foram os que apresentaram, no geral, maiores valores no α em todas as faixas de frequência, além de apresentarem em termos de NRC os maiores valores, ou seja: 0,80 e 0,81 respectivamente. O α máximo no sistema alveolar com 4 cm de espessura do substrato atingiu 0,89 nas frequências de 1kHz, 2kHz e 2,5 kHz, e nas baixas frequências valores de α entre 0,25 à 0,32 nas frequências de 100 à 200 Hz; já no sistema hexa com espessura do substrato de 6cm com sedum o α máximo foi de 0,94 na frequência de 800Hz, e nas baixas frequências entre 0,16 a 0,26. O sistema alveolar com espessura de 4 cm com grama foi o que obteve maiores α nas baixas frequências de100 a 200 Hz com valores de 0,31 a 0,38, sendo assim mais eficaz para absorção de ruído de tráfego. No geral, os coeficientes de absorção de todas as amostras dobraram o valor na faixa de 250 Hz em relação a 200 Hz. Os resultados obtidos indicam um alto coeficiente de absorção para tais equipamentos, o que sugere que a utilização de telhados verdes pode ser uma ótima alternativa de controle de ruído urbano.

Made available in DSpace on 2016-06-02T20:09:08Z (GMT). No. of bitstreams: 1 1676.pdf: 2206138 bytes, checksum: c83c9d5aa6bb880c23dbdaa15df8077f (MD5) Previous issue date: 2007-08-22 / This work aims to analyze the thermal behavior of a green roof with the Braquiária grass (Brachiaria humidicola), that reaches 1m height, comparing it with a traditional roof (concrete slab on show). Considering temperature and relative humidity data obtained through field measurements in different months, the thermal performance of the green and traditional roofs was analyzed. The inside and outside temperatures, and inside superficial of two test-cells were analyzed. The outside superficial temperatures were estimated through computation program and the solar radiation data and wind speed, necessaries for the use of this program, were provided by the Water Resource and Applied Ecology Center (CRHEA,) and the Engineering School of São Carlos (EESC), both from the University of São Paulo (USP). The results indicate that, submitted to the local climate, the green roof presents optimum performance, particularly for decreasing the temperatures of external and internal roof surfaces. In the same test-cell it was recently realized a similar research, which used the Esmeralda grass (Zoysia japonica), a short vegetation. Comparing the measurement results for cold and hot periods, it was noticed differences between the thermal performance of the two grasses. / O objetivo deste trabalho é analisar o comportamento térmico de uma cobertura ajardinada com a grama Braquiária (Brachiaria humidicola), que atinge 1m de altura, comparando-a com a de uma cobertura tradicional (laje exposta). Considerando-se os dados obtidos por meio de monitoramentos com aparelhos registradores de temperaturas e umidades relativas, em diferentes épocas do ano, analisou-se o comportamento térmico das coberturas tradicional e verde. Foram medidas as temperaturas do ar no interior e no exterior das células-teste e as superficiais internas de ambas as células. As temperaturas superficiais externas foram estimadas por programa computacional e os dados de radiação solar e velocidade do vento, necessários para a utilização desse programa, foram fornecidos pelo Centro de Recursos Hídricos e Ecologia Aplicada (CRHEA) e pela Escola de Engenharia de São Carlos (EESC), ambos da Universidade de São Paulo (USP). Os resultados indicam que, submetida ao clima local, a cobertura ajardinada apresenta ótimo desempenho, particularmente por amortecer as temperaturas das superfícies externas e internas da cobertura. Nessa mesma célula-teste realizou-se recentemente uma pesquisa similar, mas que utilizou a grama Esmeralda (Zoysia japonica), uma vegetação rasteira. Comparando-se os resultados dos monitoramentos realizados, nos períodos de frio e calor, foram detectadas diferenças entre os comportamentos térmicos das duas gramas.

Fundação de Amparo à Pesquisa do Estado do Amazonas / Green roofs have increasingly become an integral part of urban environments, mainly due to their aesthetic benefits, thermal comfort and efficiency in controlling excess runoff. However, the effects of this emerging technology in the qualitative characteristics of rainwater is still poorly understood. In this study, we evaluated the quality of rain water runoff from two extensive green roofs and a roof built with corrugated fiber cement sheets (control roof) installed in Santa Maria - RS. In addition, we analyzed the performance of both types of roof for controlling storm water runoff. For qualitative analysis of water, were determined physical (turbidity, apparent color, true color, electrical conductivity, total solids, dissolved solids, suspended solids and temperature), chemical (pH, phosphate, total nitrogen, nitrate, nitrite, chloride, sulfates, BOD, and hardness), metal (copper, iron, zinc, lead and chromium) and microbiological parameters (total coliforms and E. coli). Differences in rain water quality obtained at collection points were assessed using parametric test (Test t) and non-parametric tests (Mann-Whitney and Kruskal-Wallis test) with a significance level of 5% probability. The control of storm water runoff was analyzed from the runoff coefficient (C) and the water portion stored in both types of coverage. The results showed that, in general, GRs have not improved water quality, as indicated by some authors. On both green roofs occurred an increase of chloride, electrical conductivity, color, BOD, hardness, total coliforms, E. coli, phosphate, sulfate and turbidity. However, it was observed that GRs are able to convert the slightly acidic rainfall into basic water, which confirms its potential to neutralize acid deposition. Except for a few parameters, the quality of the collected water from the control roof did not differ significantly compared to GRs water. By comparing the results with the Brazilian environmental legislation, we noted that the runoff from all three roofs have potential for non-potable uses, such as floor and sidewalks washing, garden irrigation, toilet flushing, among others. About the performance of roofs in controlling storm water runoff, there was a significant efficiency of green roofs compared to the roof built with corrugated fiber cement sheets. This result was typified by the average values of flow coefficient, about 0.43 for GRs and 0.83 for control roof. However, the efficiency of green roofs controlling runoff proved to be very sensitive to weather conditions and antecedent soil moisture. To a future study about performance and interaction of various factors that could influence green roofs water quality and in its efficiency and controlling storm water runoff, we suggest long-term studies with different types of substrates, plant species and installation of the structures in locations with other types of occupation and environmental conditions, different from those verified in this work. / Os telhados verdes (TVs) têm cada vez mais se tornado parte integrante dos ambientes urbanos devido, principalmente, aos seus benefícios estéticos, conforto térmico e diminuição do escoamento superficial de águas pluviais. Contudo, os efeitos dessa emergente tecnologia nas características qualitativas de águas de chuva ainda é pouco compreendido. Neste trabalho foi avaliada a qualidade de águas de pluviais escoadas a partir de dois telhados verdes extensivos e de um telhado de fibrocimento (telhado controle) instalados em Santa Maria-RS. Complementarmente, analisou-se o desempenho de ambos os tipos de coberturas no controle quantitativo do escoamento pluvial. Para a caracterização qualitativa da água, foram determinados os parâmetros físicos (turbidez, cor aparente, cor verdadeira, condutividade elétrica, sólidos totais, sólidos dissolvidos, sólidos suspensos e temperatura), químicos (pH, fosfato, nitrogênio total, nitrato, nitrito, cloretos, sulfatos, DBO, e dureza), metais (cobre, ferro, zinco, chumbo e cromo) e microbiológicos (coliformes totais e E. coli). As diferenças na qualidade da água de chuva obtidas nos diferentes pontos de coleta foram avaliadas utilizando teste paramétrico (Test t) e testes não paramétricos (Mann-Whitney e Kruskal-Wallis), com um nível de significância de 5% de probabilidade. O controle do escoamento pluvial foi analisado a partir do coeficiente de escoamento (C) e da parcela de água armazenada nos dois tipos de coberturas. Os resultados apontaram que, em geral, os TVs não melhoraram a qualidade da água, como indicado por alguns autores. Ambos telhados verdes atuaram como fonte de cloretos, condutividade elétrica, cor, DBO, dureza total, coliformes totais, E. coli, fosfato, sulfato e turbidez. Contudo, observou- que os TVs foram capazes de converter o caráter ligeiramente ácido da água pluvial para básico, confirmando o seu potencial na neutralização de deposições ácidas. Com exceção de alguns parâmetros, a qualidade da água coletada do telhado controle não se diferiu significativamente em comparação às dos TVs. A partir da comparação dos resultados com as legislações ambientais consultadas, observou-se que as águas escoadas dos dois tipos de telhados apresentam características com potencial para usos não potáveis, tais como lavagem de pisos, calçadas, irrigação de jardins, descargas de bacias sanitárias, dentre outros. Com relação ao desempenho dos telhados no controle do escoamento pluvial, constatou-se uma significativa eficiência das coberturas verdes comparativamente ao telhado de fibrocimento. Esse resultado ficou tipificado pelos valores médios do coeficiente de escoamento, cerca de 0,43 para os TVs e de aproximadamente 0,83 para o telhado controle. Para melhor investigar a atuação e interação dos diversos fatores que podem influenciar na qualidade da água dos telhados verdes e também na sua eficiência quanto ao controle do escoamento pluvial, sugere-se estudos de longo prazo e com diferentes tipos de substratos, espécies vegetais e a instalação dessas estruturas em locais com diferentes tipos de ocupações e outras condicionantes ambientais distintas das verificadas neste trabalho.

El presente proyecto propuso un método experimental de medición de temperaturas internas con el fin de estudiar, comparar y entender la respuesta térmica frente al frío y al calor de cuatro células de ensayo denominadas Control (Sin vegetación) y tres células de ensayo con diferentes combinaciones de vegetación (cubiertas y fachadas) instaladas en una región de clima tropical. En ellas fueron medidas las temperaturas superficiales internas (TSI) y temperaturas del Bulbo Seco (TBS) mediante equipos específicos, un data logger, conectado a dos multiplicadores. Los datos fueron recogidos por un año y dentro de ese periodo fueron seleccionados los días críticos a estudiar. Varios datos climatológicos fueron considerados para abordar la influencia de las oscilaciones del tiempo meteorológico (episodios climáticos) en el ambiente interno construido, para lo cual fueron aplicados fundamentos de la Climatología Dinámica frente al comportamiento térmico de las células de ensayo. Los datos de las principales variables climáticas (radiación solar, humedad relativa y precipitación) fueron registradas en la Estación Meteorológica del CRHEA. Los resultados revelan que la célula de ensayo con vegetación en cubierta y fachadas, presenta más resistencia a las variaciones de temperaturas diarias, es decir, mejor comportamiento térmico, ya que muestra las menores amplitudes térmicas, los mayores retrasos térmicos, las menores temperaturas en días de calor extremo y las mayores en días de frío. Durante el día crítico de calor, las mayores diferencias entre las temperaturas máximas internas del aire, se presentan entre la célula construida con materiales convenciones y la célula que posee fachadas verdes y cubierta vegetal, de 2ºC y en torno a 3ºC en el caso de las temperaturas superficiales. Para el día crítico de frío, la diferencia entre ellas es de 1ºC para los valores de temperatura del aire, y de 2.2ºC para valores de temperaturas superficiales. Así, uso de vegetación en los edificios puede ser considerado una técnica capaz de mantener las condiciones internas más placenteras no solo en épocas calurosas, reduciendo la incidencia de la radiación solar directa, sino también en invierno, debido a su propiedad de aislante térmico que impide las rápidas pérdidas de calor, como ocurre en la célula sin vegetación. Los resultados obtenidos ponen de manifiesto que las hipótesis planteadas fueron alcanzadas, comprobando así, que el uso de vegetación combinado en fachadas y cubiertas contribuye a la mejora del comportamiento térmico, favoreciendo las condiciones térmicas internas en periodos de mayor o menor temperatura externa. / The present research proposed an experimental method for measuring internal temperatures of buildings, in order to study, compare, and understand the thermal response of four test cells against cold and heat, determined: control (without vegetation) and three test cells with different combinations of vegetation (on roofs and/or facades); installed in a tropical climate region. Internal surface temperatures (IST) and dry bulb temperatures (DBT) were measured using appropriate equipment, consisting of a data logger connected to two multipliers. Data were collected for one year and, during that period, the critical days that would be assessed were selected. Climatic data were considered in order to evaluate the influence of weather oscillations (climatic events) on the internal built environment, for which the principles of Dynamic Climatology were applied to understand the thermal behaviour of the test cells. The data obtained from the primary climatic variables (solar radiation, relative humidity, and precipitation) were recorded at the CRHEA. The results showed that the test cell with a green roof and green facades displayed higher resistance to changes in daily temperature, i.e., better thermal behavior, since it faced lower temperature intervals, higher thermal delays, lower temperatures on days of extreme heat, and higher temperatures on cold days. With respect to the critical heat day, the main differences between maximum internal air temperatures occurred between the cell constructed with conventional material and the cell that was built with green facades and a green roof, of 2°C in relation to the internal air temperature, and approximately 3°C with respect to surface temperatures. Regarding the critical cold day, the difference between test cells was of 1°C for air temperature values, and 2.2°C for surface temperature values. Therefore, the use of vegetation in construction can be considered a technique capable of maintaining the most pleasant indoor conditions, not only in hot climates, reducing the incidence of direct solar radiation, but also in the winter, due to thermal insulation properties that prevent the rapid loss of heat, which occurs in cells lacking vegetation. The obtained results show that the initial hypotheses were proven, thus confirming that the application of vegetation on facades and roofs contributes to the improvement of thermal performance, favoring internal thermal conditions during periods of higher or lower external temperatures.

In times that reveal the consequences of climate change, cities are using urban greening as a potential measure in their climate change adaptation and mitigation strategies. Greenery in the city regulates the climate and balances temperature extremes through evapotranspiration and air humidification, spending shade and increased air circulation. Many cities in Germany, such as the City of Cologne, have established funding programmes for private stakeholders to support the greening of buildings. Greened buildings contribute to a reduction of the urban heat island effect by decreasing temperatures through increased evapotranspiration, increased air circulation and air humidification and a higher reflective power (albedo). The greening of buildings also cools down the building itself forming a natural insulation layer, shading and the reflection of sun energy. However, in most cities the potential for houses that could be greened is barely utilized. This study explores variables that influence the residents’ attitudinal and behavioural acceptance towards greening their building in Cologne Deutz. Survey research was conducted based on a theoretical framework that explains how external variables form beliefs that lead to attitudinal acceptance (positive attitude) and eventually behavioural acceptance (actual behaviour). The survey was designed to examine attitudinal acceptance and behavioural intention to act, as behavioural acceptance is difficult to measure. The main variables found to influence the residents’ attitudinal acceptance and behavioural intention towards the greening of buildings were ecological aspects, such as an increase of nature in the urban environment, an improvement of the urban climate, air quality and street cooling, and climate change. Visual-aesthetic aspects also played a major role, while finances and funding possibilities had a special influence on the perceived ease of use of greening one’s building. Amongst the sample of this study attitudinal acceptance and behavioural intention were categorized as high. Reasons that could explain the low amount of greening measure implementation were a possible lack of knowledge (of funding possibilities), a low number of private property owners, and an imbalance in the distribution of tangible advantages and disadvantages amongst tenants and landlords.

The subject of the thesis is an architectural project of urban structure - a town house in Brno - Zábrdovice. The design uses the principle of multiplicity, which is characterized by multiplying of the site, using of roof planes and highlighting the object above the ground. The material of object is formed by the gradual reduction of the structure consisting of four blocks arranged around a central atrium. The building respects the height of the surrounding buildings, on the west side it has 5 floors, towards the river Svitava the height of the building gradually decreases. A significant feature is the use of greenery on roofs. Ventilated facade of the building will consist of perforated steel sheets Cor-ten and facade panels Cembrit.

Detta examensarbete handlar om utvecklingsåtgärder på platta tak. Åtgärderna som tas upp är specifikt avsedda för två hustyper på Byälvsvägen i Bagarmossen, söder om Stockholm. Hustyperna är lamell- och loftgångshus som är byggda under slutet av miljonprogrammet. Båda hustyperna har platta tak med invändigt avvattningssystem. Taken ska inom några år läggas om på grund av slitage. Syftet med detta arbete är att ta fram och undersöka olika åtgärder för att utveckla, förbättra och öka användningen av de platta taken på loftgångs- och lamellhusen.   Examensarbetet har utförts med hjälp av litteraturstudier, intervjuer och studiebesök. För gestaltning av husen och de byggtekniska lösningarna har 3D-programmet autodesk Revit använts.   Arbetet innehåller förslag på utvecklingsåtgärder som är möjliga att utföra med eller utan förstärkning av tak och stomme. I arbetet tas det även fram byggtekniska lösningar på samtliga åtgärder.   Åtgärder utan förstärkning av tak och stomme: Utveckling av takutformning Utveckling av avrinningssystem Gröna tak (lätt sedumtak) Solceller   Åtgärder med förstärkning av tak och stomme: Gröna tak (intensivt tak) Påbyggnad av lägenheter eller radhus Ökad tillgänglighet i form av hiss och trappor / This thesis is about developing measures on flat roofs. The measures that are brought up are specifically designed for two types of houses on Byälvsvägen in Bagarmossen, south of Stockholm. The house types are balcony aces blocks and lamellar houses, both are built during the so called in Swedish “million program”. Both house types have flat roofs with internal drainage. The roofs will be renovated within a few years due to wear.   The purpose is to create and examine various measures to develop, improve and increase the use of the flat roofs of the balcony aces blocks and lamellar houses.   The work has been carried out with the help of literature studies, interviews and field trips. The 3D program software Autodesk revit has been used for the design of the houses and structural engineering.   The thesis includes suggestions for developing measures that are possible to apply, with and without reinforcement of the roof and frame. This thesis also brings up structural engineering solutions on all measures.    Measures without reinforcement of roof and frame: Development of roof structure Development of drainage system Green roofs (light sedum roofs) Solar panels   Measures with reinforcement of roof and frame: Green roofs (heavy roofs) Adding storeys of apartments or townhouses Availability in form of elevator and stairs

Våra städer fortsätter att exploateras och kravet på ökade bostäder gör att flera av våra grönyteområden byts ut mot hårda ytor. Dessa ytor bidrar direkt till klimatförändringar och miljöproblem, så som till exempel försämrad luftkvalitet, buller, ökat vattenstånd och ett varmare klimat. Miljöproblemen påverkar även den biologiska mångfalden och påverkar människans välbefinnande och på längre sikt överlevnad. Rapporten innehåller en studie om hur grönstrukturen i Örebro kommun ser ut och även vilket värde och vilka byggnadstekniska, ekologiska, ekonomiska och sociala egenskaper och effekter som finns av att anlägga fler gröna tak. För att ta reda på detta gjordes en litteraturstudie för att se hur grönstrukturen planeras i Örebro kommun. Det gjordes även en litteraturstudie för att ta reda på vilka nyttor och värde det finns med gröna tak ur ett ekonomiskt, ekologiskt och socialt perspektiv i Örebro kommun. För att tydligare kunna redovisa värdet av gröna tak i jämförelse med konventionella tak utfördes en fallstudie med beräkningar på området Södra Ladugårdsängen där två olika fall med olika stor andel gröna tak beräknades och jämfördes. Studierna visar på att Örebro kommun har en informativ och bred planering för grönstrukturen och att det samhällsekonomiska värdet av gröna tak i Södra Ladugårdsängen är mycket högt. Slutsatsen av dessa studier är att det finns god potential för att anlägga gröna tak i Örebro kommun med många goda effekter som följd, dock är den ekonomiska investeringen det kräver ett viktigt hinder. Grönstrategin i Örebro uppmuntrar denna typ av lösningar men det finns rum för förbättringar och kanske bör ett större tvång eller incitament införas för att nå de mål kommunen vill. / Our cities continue to be exploited and the demand for increased housing means that several of our green space areas are being replaced by hard surfaces. These surfaces directly contribute to climate change and environmental problems, such as reduced air quality, noise, increased water levels and a warmer climate. Environmental problems also affect biodiversity and affect human well-being and long-term survival. The report contains a study of what the green structure in Örebro municipality looks like and what value and what building technical, ecological, economic and social properties and effects there are of constructing more green roofs. To determine this a literature study was conducted to find out how the green structure is planned in Örebro municipality. A literature study was also conducted to find out what benefits and values there are with green roofs from an economic, ecological and social perspective in Örebro municipality. In order to be able to more clearly report the value of green roofs in comparison with conventional roofs, a case study was performed with calculations in the area of Södra Ladugårdsängen, where two different cases with different proportions of green roofs were calculated and compared. The studies show that Örebro municipality has an informative and broad planning for the green structure and that the socio-economic value of green roofs in Södra Ladugårdsängen is very high. The conclusion of these studies is that there is good potential for constructing green roofs in Örebro municipality with several benefits as a result, however, the financial investment it requires is an important obstacle. The green strategy in Örebro encourages this type of solution, but there is room for improvement and perhaps a greater coercion or incentive should be introduced to achieve the goals the municipality strives for.

Gröna tak är en gynnsam lösning till urbaniseringens negativa effekter, som exempelvis minskad biologisk mångfald, sämre luft och problem med dagvattenhantering. Sedumtak, ängstak och biotoptak är några av de olika typer av gröna tak som finns. Sedumtaket har många fördelar och passar bra till Sveriges nordliga klimat. Syftet med denna studie är att studera hur bibliotekets sedumtak på Högskolan i Gävle har fungerat under en tidsperiod på 18 år, samt anledningen till valet av det gröna taket. Frågeställningarna ska besvaras med hjälp av en litteraturstudie kombinerat med intervjuer.  Litteraturstudien framhåller att det finns flertalet fördelar med gröna tak såsom god dagvattenhantering, ökning av fåglar och insekter, bättre luftkvalitet, minskad energianvändning i byggnader, minskar den urbana värmeöeffekten och att det är estetiskt tilltalande. Fördelarna blir mest märkbara i urbana miljöer med brist på grönytor och i sydligare klimat. Underhållsbehovet av gröna tak beror på flera faktorer. I Sverige är extensiva taksystem vanligast, vilket är den tunnaste tjockleken av gröna tak. Denna typ kräver minst underhåll och kostnader. Underhållet sker med gödsling, bevattning och ogräsrensning vid behov.  Det resultat som gick att komma fram till från intervjuerna var att bibliotekets gröna tak främst valdes på grund av att det var estetiskt tilltalande och passade bra in i omgivningen. En tävling anordnades av Akademiska Hus för att ta fram det bästa förslaget på det nya biblioteket där tre olika arkitektkontor deltog. Det vinnande förslaget blev biblioteket med det gröna taket ritat av Tirsén och Aili Arkitekter (idag Stark Arkitekter) som fångade intresset för många. Från att det gröna taket byggdes till idag, har knappt något underhåll behövts och det underhåll som har utförts har varit enligt planerna. I början, under takets garantitid, framkom det däremot att det slarvats med underhållet på grund av brist på kunskap. Förutom några mindre avvikelser i underhållet och att det gröna taket har krävt noggrannare projektering samt ett mer komplicerat grundarbete, har taket fungerat precis som planerat.  Den slutsats som går att dra utifrån arbetet är att ett grönt tak kan vara ett bra alternativ om rätt förutsättningar för taket finns. Fördelarna med ett grönt tak är många, däremot inte lika påtagliga i ett nordligare klimat eller i en icke urban miljö. Litteraturstudien visar att rätt typ av grönt tak kräver minimalt med underhåll. Intervjuerna bekräftar även att detta stämmer på bibliotekets gröna tak. Det gröna taket har fungerat enligt planerna utan några komplikationer och kommer att fortsätta göra, om taket sköts på liknande sätt som det har gjort från att det byggdes. / Green roofs are a favorable solution to the negative effects of urbanization, such as reduced biodiversity, poorer air and problems with stormwater management. Sedum roofs, meadow roofs and biotope roofs are some of the different types of green roofs available. The sedum roof has many benefits and is well suited to Sweden’s northern climate. The purpose of this study is to study how the library’s sedum roof at the University of Gävle has functioned over a period of 18 years, as well as the reason for choosing the green roof. The questions must be answered using a literature study combined with interviews. The literature study highlights that there are several benefits of green roofs such as good stormwater management, increase in birds and insects, better air quality, reduced energy use in buildings, reduced heat island effects and that it is aesthetically pleasing. The benefits are most noticeable in urban environments with a lack of green spaces and in more southerly climates. The maintenance requirement of green roofs depends on several factors. In Sweden, extensive roof systems are most common, which is the thinnest thickness of green roofs. This type requires the least maintenance and costs. Maintenance takes place with fertilization, irrigation and weeding if necessary. The result that can be drawn from the interviews is that the green roof of the library was mainly chosen because it was aesthetically pleasing and fitted in well with the surroundings. A competition was organized by Akademiska Hus with the reason to produce the best proposal for the new library, which three different architectural offices participated in. The winning proposal was the library with the green roof designed by Tirsén and Aili Arkitekter (today Stark Arkitekter) which caught the interest of many. From the construction of the green roof to today, hardly any maintenance has been required and the maintenance that has been required has been according to the plan. In the beginning, during the roof's warranty period, it emerged that maintenance was neglected due to a lack of knowledge. Apart from some minor deviations in maintenance and the fact that the green roof has required more careful planning and more complicated foundation work, the roof has worked exactly as planned. The conclusion that can be drawn from the work is that a green roof can be a good alternative if the conditions are right. A green roof's benefits are many, but not as obvious in a more northern climate or in a non-urban environment. The literature study shows that the right type of green roof requires minimal maintenance and the interviews also confirm that this is true according to the green roof of the library. The green roof has performed as planned without any complications and will continue to do so if the roof is maintained in a similar manner as it has been since it was built.

Low slope roofs are roofs with an inclination between 1:16 and 1:4 and have been constructed and preferred for many years due to the benefits they present. The goal of the present work is to study the following problems of low slope roofs, as they are suggested by previous relevant theses and the current needs of the market. Moisture transfer in low slope roofs with constant exposure to high levels of relative humidity. Is protection against corrosion required for steel beams placed directly under the external membranes? If yes, what kind of protection is that? Roof drainage on low slope roofs The study of the first subject was based on simulations of this type of structures in order to see how external moisture affects the moisture level and the potential for corrosion on steel beams. The main goal was to conclude whether we can actually build inverted roofs with steel plates or beams lying right under the roof membrane and what kind of protection is more appropriate to apply, in case it is required. According to the literature review conducted on roof structures, corrosion and corrosion protection, as well as the results of the simulations, the main factor defining the corrosion potential is the indoor environment. Moreover, paint coating seems to be the indicated anticorrosive protection. Regarding drainage, the study focused on the literature review of the current situation, the solutions applied, the existing regulations and guidelines regarding the type of systems used (full flow or gravity, internal or external), the construction of drainage valleys (inclined or horizontal) and the placement and dimensioning of drains and overflows, in order to create a short handbook with issues to be considered by the roof engineer. The main conclusions are that drain valleys are suggested to be constructed completely horizontal, in order to facilitate the cooperation between drains, and that full-flow systems are more efficient than gravity ones and should be preferred, as long as the roof is not exposed to solid material and prone to its accumulation around drains (e.g. roofs covered with vegetation or stone ballast, with overhanging or nearby trees).