Mock-Up Presentation of the Gate Tower to the Hill Fort at Liptovská
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Discussion Mock-up Presentation of the Gate Tower… Fig. 2 The tower at the stage of a fi nished rough construction in the summer of 2003. n Mock-up Presentation of the Gate Tower to the Hill Fort at Liptovská Mara Oto Makýš Department of Building Technology, Faculty of Civil Engineering, Slovak University of Technology, Bratislava, Slovakia * l The author discusses the importance of including maintenance costs while planning an experimental construction based on the example of Lip- tov ská Mara. Introduction Empire in Southwest Slovakia which Reconstruction of destroyed build- can be up to 2000 years old). All these ings or their parts is not uncommon reconstructions have a common base in Slovak building practise, especially – the building techniques originally in the area of monument renovation. developed by the Romans, which were It mostly concerns buildings in brick used not only on the territories and in and stone or their parts built within the period of the Roman Empire but far the last 1200 years (with exception of beyond both its territorial and temporal buildings from the Age of the Roman borders. With the exception of period * Translation: J. Kateřina Dvořáková euroREA 1/2004 137 eeuroREA1.indburoREA1.indb 113737 222.2.20052.2.2005 223:02:193:02:19 Discussion Mock-up Presentation of the Gate Tower… (medieval, modern) developments or experiments are primarily looking for local modifi cations it has fi rst funda- possible solutions and testing them. mentally changed during the 20th cen- tury. Th at means that the reconstruc- Future of an Experiment tions of destroyed ‘ancient’ structures Some of the recent experimental can be based on more or less identical constructions seem to concentrate only or analogous building solutions pre- on research, plan and execution of the served in other parts of Central, West- building. Th e question of further main- ern or Southern Europe (for example tenance has been neglected. Nearly every use of lime mortar). construction can have apart from the In recent years an increasing num ber research also an important and interest- of experimental constructions have ap- ing presentation function. Th is means peared – the building of structures from securing the further existence of the extinct cultures or from early phases constructions. It is therefore necessary of building development which are not to include the problem of maintenance well known and where the construction in the planning of the experiment. Th at and its details have to be based on local does not only infl uence the current so- archaeological research or archaeological lution of the construction but it might research of analogues. Th is concerns es- also instigate diff erent solutions of some pecially constructions built from organic unknown elements – maybe even solu- materials not only from pre- or protohis- tions closer to the original data. It is tory but also from the Middle Ages. Th e therefore necessary to determine straight problem of construction can be divided at the beginning if the building was built into several overlapping areas – ques- quickly or slowly, for short or long term tions, which have to be answered: use. It seems that most of the buildings l Design of the building in the past, as nowadays, were built for l Th e static schema extended use. Th e constructions from l Building materials organic materials are usually buildings l Solution of construction details of a high utility value and can survive l Used technology for a long time (for example preserved medieval roof timbers). Th e key lays in The entry information can only the preparation of building materials, par tially be specifi ed. Oft en most of the construction methods and mainly in above mentioned key information is continuous maintenance: missing. Use of analogous solutions based a) Th e composition and especially on other fi nds, oft en from large areas the proportion of tree species were dif- or parts of Europe does not necessarily ferent in the past. Th is also concerns supply suffi cient information. It must the quality of wood mass used, which also be pointed out that use of analogous is generally higher than it is today. solutions from later folk buildings might Th e environmental pollution today is be misleading. Construction details and substantially higher. In Slovak biotopes woodworking technology have devel- some of the species have been sup- oped – most preserved wooden cabins pressed (for example yew tree), some were built at the end of the 19th and be- others without natural enemies have ginning of the 20th centuries. Th erefore been introduced (for example acacia) 138 euroREA 1/2004 eeuroREA1.indburoREA1.indb 113838 222.2.20052.2.2005 223:02:203:02:20 Discussion Mock-up Presentation of the Gate Tower… and also there have appeared new pests tained before the start of the building. towards which Slovak biotopes are not It is clear that if the construction should resistant (for example the Domestic not disappear within few years regular Dry Rot Fungus Serpula lacrymans) upkeep is necessary. (Reinprech-Žák, 1998). c) Th e problems might be solved by, b) Modern methods solve the prob- for example, the use of acacia for posts lems of maintenance of wooden build- placed in ground, bandaging of the un- ings with the use of fundamentally dif- derground part of a post with bandages ferent building materials (concrete, steel, soaked with chemical preservatives, pres- plastic) which are unauthentic solutions, sure treatment of the underground parts, unsuitable for experimental construc- consistent placing of bottom beams on tions and besides which are not corner stones of suffi cient height, digging absolutely effec- tive. circumferential channels, possibly even Therefore it is hidden drainage around the building to necessary to de- take rain water away quickly, placing of termine what drainage above the buildings or to divert way the future underground water and so on. Also for existence of the example covering straw or reed roofs with constructions thin nets protecting them against damage can be main- from birds and wind, regular airing of the building including the securing of neces- sary airing throughout the whole year. d) Th e placing of wooden beams into constructions – that means the con- struction details used – should be done in a way to prevent wa- ter pene tration into the Fig. 9 Finishing of euroREA 1/2004 a roof frame.139 n eeuroREA1.indburoREA1.indb 113939 222.2.20052.2.2005 223:02:203:02:20 Discussion Mock-up Presentation of the Gate Tower… structure, to allow it respectively to run g) If a fungi infection is discovered the off and dry the organic material as fast action depends on its origin. If the infec- as possible (see placing of box-frames on tion came with the building wood then the corner stones). Even then it is not always infected part (and oft en also the adjacent possible to prevent the wooden structures parts) should have to be immediately from getting wet, especially the posts. and carefully removed and burnt at a safe Ways to repair wooden buildings with distance to stop the infection spreading. exchange of single damaged parts for If the infection is caused by neglect which new ones, without dismantling the whole results in a rise of the relative level of wood construction, have existed probably as humidity (for example insuffi cient airing, long as wooden structures and were part rise of the soil level up to the wooden of the constructors’ know-how. structure and so on) it is possible to try e) Regular maintenance (at least once (with airing, removing the soil and so a year – in the spring) means the clearing on) to transform the acute infection into away off grass, self-seeded trees and the a latent state, when the infection does not lowering soil deposits along the wooden develop any more (or minimally) and the constructions. It is not necessary to heat infected structure can survive without the the buildings because the drying eff ect replacing of parts for some time. is usually not proportional to the eff ort h) In any case it is necessary to take and expenses with the exception of one into account that aft er some time it would time drying of very damp constructions. be necessary to replace some elements of Otherwise regular airing is suffi cient. the building. Th e organic roof cover if it During maintenance it is also necessary is not continuously preserved by smoke, to pay attention to the condition of the has to be replaced under normal condi- roof and immediately repair any damage tions every 10 to 20 years, damp wooden which would allow water penetration. It beams in less than 10 to 15 years, earth is also useful to check the building during fast posts (depending on the preservative strong or long lasting rains which reliably use) in about 10 to 15 years. show any openings. i) Th ese ways of operating and main- f) Under condition where the hu- taining a building close to the original is midity level in the construction does not demanding on time, expenses and human cross 10%, or respectively 20% limits for power. Dependence on volunteers is not a more than 3 months, the structure has a solution, as it is possible to say from expe- chance of a long lifetime. Use of chemical rience that volunteer groups are mercu- preservatives is debatable because their rial (usually they endure the upkeep of a eff ect is on one hand time limited (it is structure for about 3-5 years). Th erefore necessary to renew it aft er certain time) the best solution is the founding of a and on the other technologically depend- professional service which looks aft er the ant (the most eff ective method is pressure operation and upkeep of the structure impregnation).