Steep Roofs Research Articles

Detail, Facture, and Colour in the Architecture of Polish Single-Family Houses after 1989

The article presents single-family houses architecture transformations since 1989, with particularly close attention paid to the significance of detail, facture, and colour. The article presents the architecture as an art of designing and building facilities with both use and aesthetic value, an art of shaping space and building forms. Architectural work should correspond to the intended function, technique, economic and aesthetic requirements, thus shaping all elements of human immediate environment, both inside and outside of the building. Architecture of the building is perceived as form, structure, and function, as well as detail, facture, and colour. Facture and colour are created through materials used for external finishes. The solid of the building is noticed first while looking at the building, then the finishes detail such as colour, facture, and detail. Materials for external finishes are commonly selected for their aesthetic value equally with their technical characteristics. The detail was always a characteristic element of style. However, currently the fashion for details can be observed, the fashion for usage of materials for external finishes and inter-connected with that colour and facture. The architecture of Polish single-family houses underwent considerable metamorphosis after system change of 1989 – from destitute in form, devoid in detail and colour socmodernism, to architecture extremely varied in terms of form, utilised structures, materials, and detail. Hence, appearance of the phenomenon called fashion can be observed in the architecture, understood as constant changeability, seeking novelty, and creation based on opinion-forming centres. The architectural fashion consists of form, function, structure, building materials, detail, facture, and colour trends, e.g. after rejecting socmodernism, steep roofs characteristic for single-family houses trend started. After 1989, initially individual single-family house projects were created; however, rapidly developing building market precipitated the creation of catalogue solutions, repetitive and conventional. Currently, potential customers have access to catalogues of numerous design studios and companies, every last one including few dozens of comprehensive constructions design options of single-family house at the fewest. In the conventional catalogue designs, steep roofs began to gain popularity, becoming increasingly complicated with various choices of roof windows as time passes. The entrances are frequently adorned with porticos and columns. So-called “mansion architecture” of the single-family houses has developed. Recently, fashion alluding to modernism of 1920s has developed in the single-family houses architecture. New trends among architects are adapted with increasing frequency by investors looking for unconventional solutions. The neo-modernism trend is noticeable predominantly in individual projects; however, it appears in catalogue propositions with increasing frequency. Designs of single-family houses of simplistic shape and distinct expression emerge, with flat roofs, minimalistic detail, and vital, carefully chosen in terms of facture and colour, material solutions of wall finishes. Apart from the conventional solutions, presently the building market offers a vast variety of meticulously prepared, factory-made, and thoroughly checked in various realisations details. Architects discontinued using manufactured and individually designed detail in favour of utilising conventional solutions for designed objects. In a well-designed single-family house, facture, colour, and detail of materials utilised in external finishes should harmonise with the building shape and form.

Determination of Solar Reflectance Index of Ceramic Coatings for Use in outside Surfaces

In this study, thermal and optical properties (emittance and reflectance of solar radiation) of different colors ceramic tiles for use in outside surfaces were measured. Although widely used in the brazilian residential market, these materials are not properly characterized with respect to these properties. The thermal emittance measures were performed using an emissometer (D&S pattern SA1) and the solar reflectance using a spectrophotometer UV-Vis-NIR (model Lambda 1050). These properties are important for the determination of Solar Reflectance Index, SRI, that may help designers and consumers to choose the appropriate materials to make their buildings more energy efficient and comfortable. The SRI indicates the ability of a surface to reflect solar radiation and mitigate the temperature rise of surfaces, being used in LEED certification (Leadership in Energy and Environmental Design) to evaluate the performance of some opaque elements in constructions. The studies revealed a wide variation of SRI (values are between 72 and 22) in the same product with different colors. In particular two samples showed SRI lower than 29, which place them even below the minimum requirement of LEED for application in some types of outside surfaces, as steep roofs and pavement materials (LEED v. 2009 used in Brazil).

Heavy rainfall: An underestimated environmental risk for buildings?

Although impacts of heavy rain on buildings in urban areas are often extensive, the public usually underestimates the negative consequences of that environmental risk compared e.g. to storm or hail events. However, the intensification of extreme weather events due to climate change as well as the rising physical vulnerability of assets are going to trigger the increase of impacts on the built environment. Heavy rain events are often highly localised that makes it difficult to estimate their probability and magnitude accurately. High intensity rain affects buildings both directly as well as indirectly.First, engineering surveys have already proven the broad variety and high physical vulnerability of building constructions that are directly and frequently affected by invading water during heavy rainfall events: flat roofs, roof terraces and balconies, connections between steep roofs and other building parts, soil-covered slabs of underground parking, soil-contacted basement walls and bottom plates as well as windows and external doors. It became evident that most damage is avoidable if exposed constructions become more resilient. Nevertheless, any adaptations require expertise on the demanding damage processes in order to explore deficiencies and to reduce physical vulnerability of building constructions exposed to heavy rainfall. In response to that challenge, the paper describes an engineering approach for the systematic classification of physical vulnerability criteria based on empirical research. A developed classification scheme allows the ex-ante examination of typical failure modes and the evaluation of negative consequences of heavy rainfall at individual building level. The topic is of high relevance, because the classification scheme may act as a capable tool for the prospective planning of adaptations towards more resilient buildings.Second, heavy rain may result in urban pluvial flooding due to sewer overflow that cause severe damage to buildings. A comprehensive study of the impacts and the consequences in Dresden (Germany), presented in the paper, revealed that the potential risks of flooding from sewers due to hydraulic overload can be estimated on building scale using the model approach IVART (Integrated Spatial Vulnerability and Risk Assessment Tool). Modelling results provide the basis to quantify the effectiveness and efficiency of flood resilience technologies.

An Assessment of the Asphalt Shingle Roofing Process for Residential Buildings

Asphalt shingle roofing is performed by specialty contractors in the construction industry with the roofing crew performing tasks in different areas on the roof simultaneously. While asphalt shingle roofing materials have improved, the roofing construction process has not changed significantly over the past 70 years.This paper describes the process, factors that affect the productivity of the workers, and methods for calculating productivity in terms of man-hours worked and cost per unit output. Safety is also a concern in roofing. While falls from roofs are a major cause of injuries on the construction job site, other injuries common to roofers include sprains and strains to the back, knees and ankles. The trend of constructing steep roofs, common in Texas high end residential homes, are implicated in these injuries. Safety plans and worker safety climate are low priorities for financially strapped construction companies. Designing out the hazard would be more effective than Personal Protective Equipment (PPE) in preventing accidents in the roofing industry.The paper concludes that research and development are needed to improve roofing construction methods to provide a safe and healthy environment for the worker and reduce costs of construction.

Effects of Using Recycled Asphalt Shingles in Open-Graded Friction Course on Flexible Pavement Performance

Abstract Recycling inert construction wastes is one of the approaches to promote sustainable development. In North America, the majority of steep roofs are covered with asphalt shingles. Re-roofing and manufacturing of asphalt shingles create a large amount of waste. This paper examines the use of recycled asphalt shingles (RAS) in open-graded friction course (OGFC). OGFC mixtures with and without RAS were prepared and tested for rutting resistance, indirect tensile strength, moisture-induced damage, and dynamic modulus. The dynamic modulus was also used to examine the responses of flexible pavement under assumed structures, temperature levels, and loading conditions. In addition, a section of major interstate highway in the United States surfaced with the RAS OGFC mixture of this study was used for performance monitoring. The use of RAS in OGFC was found to enhance its rutting performance, generally increase indirect tensile strengths of the tested specimens, generate pavement structural responses similar to those of a conventional OGFC mixture under the same loading conditions, and improve pavement’s fatigue life. Except for clogging, no obvious distress was found in the trial section after being used for two and a half years. Future research is suggested for the development of an appropriate laboratory evaluation method for the assessment of OGFC durability.

Churches in Early Medieval Ireland: Architecture, Ritual and Memory (review)

Churches in Early Medieval Ireland: Architecture, Ritual and Memory. By Tomas O Carragain. (New Haven: Yale University Press. 2010. Pp. xvi, 392. $100.00. ISBN 978-0-300-15444-3.)This is a marvelous book. It is big and beautiful, with many full or half-page photos of churches and other monuments (obviously taken on Ireland's few sunny days). Although there are plenty of archaeological and architectural details in its pages, the text is no mere catalog of digs and ruins. Instead, in a persuasive and lively analysis of Christian architecture in early-medieval Ireland, O Carragain fearlessly tackles some of the big questions of Irish medieval history- the kind that used to cause fistfights at Celtic studies conferences. One of the biggest is: Why did the Irish build the same kind of tiny, primitive-looking houses of worship over seven centuries? Tomas O Carragain not only answers this question but also explains how the Irish built their religion, why they chose to build and practice as they did, and how their version of Christianity changed in some ways but not in others during the early Middle Ages.O Carragain begins in the fifth century when Britons such as St. Patrick first began to preach in Ireland. Previous scholars assumed that the earliest founders of Irish ecclesiastical communities relied on indigenous technologies such as the drystone corbelling used in prehistoric tombs, to build sturdy little stone churches in native style. For instance, the strangely boat-shaped Gallaras oratory in County Kerry, well-known to tourists and recipients of their postcards, was assumed to be a relic of the earliest days of Christianization. As O Carragain shows, however, Christian builders first peppered the island with wood, turf, and wattled churches that they constructed in (what they imagined to be) Roman forms and according to (what they interpreted as) biblical principles. Then, beginning in the seventh century or so, the most prosperous and powerful church settlements (such as Armagh and Kildare) replaced wood churches with mortared stone structures or added new stone churches to the collection of monuments already standing within their circular enclosing walls. Yet even when working in stone, builders stuck to the same familiar rectangular shape, adding steep roofs and old-fashioned antae, because these features recalled the golden age of conversion and saintly foundation. Although other European Christians constantly updated their church architecture, the Irish remained stubbornly attached to their small, unicameral, rectangular buildings well into the second Christian millennium. …

II. Le Sud-Ouest de l’Allemagne

Urban dwellings in Gothic Bavaria, by Konrad Bedal Most Bavarian cities took on their present form during the thirteenth and fourteenth centuries. This is also the case of the houses, both the interior and exterior. The main changes include 1) the passage from rambling constructions to larger, more compact buildings ; 2) the replacement of one-room dwellings, either post and beam or masonry structures, by large multi-roomed half-timbered or stonework constructions ; 3) the general adoption of the Stube (a combined living and eating room), with wooden walls and ceiling, as the main room, situated usually on the first floor. If the profile of the old cities is characterised by tightly packed houses with steep roofs, the South-east also has gently pitched shake roofs. From the thirteenth century on, buildings may be oriented either with the gable or the gutter wall facing the street ; the latter predominate in the South, former in the North. Regensburg has a special place in Bavaria, preserving that largest number of residences and private towers north of the Alps. Two major zones are distinguishable in Bavaria as of the fourteenth century. Masonry construction, principally brick, prevails in the South and East (Upper and Lower Bavaria), whereas timber-frame construction spreads through the North and West (Franconia and Swabia) after 1250. The development and characteristics of wood-frame construction in Franconia is well known from the nearly 2000 preserved medieval buildings. The oldest are storied post and beam dwellings measuring 5 x 10 meters to 12 x 30 meters. Short post construction in upper stories is known from 1300, but only becomes common in Franconia between 1400 and 1500, although one finds corbelling on gables and gutter walls, even in the oldest buildings. Softwood is most common, but oak is also used for the exterior facing. The infilling is cob, ashlar or brick, or even plaster. Many city dwellings have a rear gallery, usually on the first floor, that gives access to the latrines, an amenity that finds favour in the fourteenth and fifteenth centuries. Narrow wings are often added at the rear of the houses ; they border a narrow courtyard which is closed at the end by a fourth structure that is used as a barn or complementary dwelling. The ground floor serves as a stable, whereas the upper storey has sleeping rooms and Stuben. The interior courts are characteristic features of the homes of the wealthy in southern Germany. Although the majority of the courts with a regular layout date from the sixteenth and seventeenth centuries, precursors cans be found in the fifteenth. Galleries are often in wood, but some masonry arcades rest on columns, especially south of the Danube and constitute the highpoint of domestic urban construction in Bavaria.

Fusion of 3D building models derived from first and last pulse laserscanning data

The work presented in this article is part of a project of collaborative research center 461: “Strong earthquakes”. Geometric modelling of buildings in urban areas, detecting and interpreting their changes is necessary to obtain fast damage information after earthquakes as important input for a disaster management system. Airborne laserscanning was chosen as data basis for this application due to its advantages like extensive independence of weather and lighting conditions, high accuracy and measurement density. Investigations have shown that building models created by means of laserscanning data have some systematic deviations compared to accurate reference models. Modern laserscanning sensors are able to record first signal response (first pulse) and last response (last pulse) simultaneously. Dependent on these modes the derived building models show system inherent differences: a principle enlargement using first pulse mode and an analogous reduction in last pulse mode. Their amount is dependent on the flights parameters and the resolution of the derived data set, here the enlargement was about +1.2 m and the reduction about −1.2 m. It will be demonstrated that a fusion of two models of a building, derived on the basis of first and last pulse data respectively, leads to an enormous accuracy improvement. At this state the fusion process is—according to the used quality assessment—divided into a positioning and height component. An algorithm for the determination of a centerline between the borderlines of the two building models will be presented. This line is used for adjustment of the position. For adjustment of the height, i.e. the roof structure, vertical distances inside corresponding planes of the two models are used to calculate a new adjusted one. The final building modelling is based on the intersection of these adjusted planes. The resulting building models fit much better to their related reference models. The mean positioning deviation decreases to ≈0.25 m, while the deviations in height are estimated between ≈0.02 m (flat roofs) and 0.10 m (steep sloped roofs). This significantly improved accuracy level lies below the accuracy of original laserscanning data and therefore enables, beside the recognition of building damages, a great variety of applications in urban environment like generation of 3D city models, e.g. for planning purposes.

Performance of modern products for underlay in residential buildings

The performance of some modern products intended for underlayment in steep roofs was studied. Properties considered were durability against thermal degradation and against water. Also the effect of combinations of water, heat and cold were studied as well as natural ageing. The effect of water flowing over installed products was also studied. The studied products were foils or sheets, most of them containing polymers. The products were found to function properly when installed. Some of them declined in strength with ageing. Products with cellulose fibres started to curve and bend by water load. Some plastic foils could be permanently deformed when mechanically loaded. Some of the foil products also had problems with water-pool formation at the eaves, when prone to flowing water at low slopes. These processes do not necessarily result in leakages but may be harmful to the function of the roof cover. It seems important to install the outer covering quite soon after mounting the underlay, as the underlay products studied have limited durability against natural ageing or water. When properly used they seem to have a good and economic performance.

積雪地域における屋根用塗装鋼板の表面劣化に関する研究

The deterioration of paint-coated steel sheets which are used as roofing materials for heavy snowfall area in Japan, has been investigated with special attention to their morphological changes in the microscopic surface. Some samples of them were taken from the roofs of dwelling houses to make a microscopic observation and measure the surface roughness of the sheets. The result shows that the surface roughness of paint layer gradually increases in depth till about five years. Afterwards, from that time till about fifteen years there is little change of the surface roughness, however, after that, more rapid change occurres on surface due to rust that causes the sheets swell their thickness. It also reveals that there is a big difference in the surface roughness of the sheet on steep sloping roofs between the even roofs. Not only slight damage but also abrasions have been noticed on the film in proportion to the direction of the roof slope. This paper obviously proves to have something to do with snow and ice on the roof.

On House Types and their Distribution in the Upper Streams of the Kiso River and its Environs

In the mountanious regions of Central Japan a characteristic house type is wide-spread, which with its shingled, less steep, and two-sided roofs reminds us of chalets in the European Alps. Although the external appearence is nearly the same everywhere in these regions, the plan of houses, i.e., the room arrangement, is more or less different from place to place.In the southwestern region of Nagano Prefecture, along the upper regions of the Kiso River, Dr.G. Fuzishima, Prof. of Architecture, Tokyo Univ., classified in 1947 two types of the house plan: a) Ontake-type (Fig. 2 and 3) and b) Araragi-type (Fig. 4 and 5). Both types, belong to the Hiromagata-type in general, and present a quite distinct principle of room arrangement. On the other hand, on the left bank of the Hida River, one of the tributaries of the former in the northwest, we found in 1958 another type of house plan, which we should like to call the Takehara-type (Fig. 9).These three types mentioned above divide their own realm, and come into contact with each other in the Sakashita-Midono region in the upper course of the Kiso River.Their distribution and nature are not yet decided. However, we may be able to say, at least, that the investigation of the problems might play an important role in the field of study about the geography of rural habitations in Japan.

Advance in Retrospect

The business of preparation is complete. The men know what work lies in front of them, if life is spared, before the sun, now setting behind the steep roofs and towers of Bailleul, rises again above the fortified ridge of Messines, still held by the enemy. As the column leaves its high resting place on Mount Ravetsburg and winds on towards the darkening East, a ground mist veils the sordid straggle of wreckage in the valley, where heaped debris of earth, metal and smouldering timber had once been trains of linked trucks loaded with explosives. A chance bomb dropped from the air yesterday had blown wagons, wheels, rails, sheds and men skywards in blasts of flame.The thick dust stirred by the movement of many men fills eyes, mouth and nose, for the grass underfoot that once carpeted the country lane has been crushed out of life, and the earth that fed it has been powdered by the tread of innumerable feet. Yet the June evening is still redolent with hawthorn; and the scent of the hedgerows softens the acrid impact of sweat. Shellfire has not yet violated the virginity of trees in full leaf; and the eye lingers on their shapeliness as if to stamp their form on the mind. Within an hour the memory of them will seem as fantastic as the prospect of the trees further ahead which stand with stark limbless trunks pared of life-giving foliage by the engines of war.