BİR AHŞAP YAPI KÜLTÜRÜNÜN YOK OLUŞU: GÖLYAKA

Disappearance of timber construction culture in the Turkish countryside is an indication for the loss of architectural merits. It is in a sense the result of vanishing values of the society related to life, education, economics, technology and culture. The loss of traditional space qualities and its details means loosing values in the aesthetical, functional and structural aspects of architecture. More interestingly, it is this very phenomenon that also caused the collapse of inadequate buildings at the 1999 earthquakes, and transformed a natural event into a tragic catastrophe. The disintegration of timber construction culture started decades earlier perhaps with the introduction of modern materials and in particular the reinforced concrete construction system. The choice for this new construction method is based not only in economic reasons of low-cost, low-maintenance and durability, but also in social preferences towards modern mode of life. Yet, timber construction heritage with its design theory and construction know-how included could be revitalized and rehabilitated with the contemporary materials and techniques. This re-evaluation is closely related with improvement in economical, social and cultural features of the whole society. The evolution of the architectural heritage and appreciation of its products is necessary for the establishment of contemporary architecture. Gölyaka town, located close to Düzce between Adapazarı and Bolu, is virtually on the North Anatolian Fault line. Gölyaka is a typical example in the process of loss of traditional timber construction culture, and a case in improper use of modern materials and techniques such as reinforced concrete. The early settlers of Gölyaka came from various parts of the Ottoman Empire such as Caucasia, Northern Iraq, Balkans in the late 19th century, and from Eastern Black Sea during the Republic Era. These migrants brought their timber construction traditions with their other folkloric assets. Thus, a rich timber architecture has evolved in and around Gölyaka, mostly in timber framed houses, some log-cabin houses and the Serander. Serander is a prototype of grain store, various types of which are widely used in many areas of the world like Japan, Central Asia, Black Sea Region, Central and Northern Europe. With the investments of migrant workers in Germany from the region, and building new houses in Gölyaka especially after 1970's, the construction tradition of the town began to change. The traditional timber construction system was abandoned to give way to the so called modern materials and systems such as reinforced concrete skeleton, and the use of bricks or concrete blocks as infill material of the walls. In this transformation from timber to concrete, and from traditional to modern, the general interest is in the 'new' qualities. Yet this change was guided above all, by the 'new' building economics. Timber which required periodical maintenance was considered inferior when compared to the low-maintenance concrete system. At the same time, timber construction did require skilled workmanship especially in the intricate joints which are time-consuming and expensive in production. Thus, timber construction was abandoned and timber construction know-how gradually disappeared. On the other hand, the new material, reinforced concrete was inappropriately designed and applied. In the 17 August and 12 November 1999 earthquakes most of the concrete buildings collapsed, as in many other towns, causing immense loss of life. In other words, the community did not only lost track of its traditional construction heritage, but could not establish a sufficient substitute in terms of modern construction techniques. This general deficiency could be followed into the components of the traditional timber construction system in terms of plans, floors and roof construction, foundations and joints. The major construction failures could be indicated by re-evaluating the traditional timber knowledge and its degeneration in applications and details. One of the first architectural loss of value is related to space quality, as observed in the Karnıyarık house plan type that has been widely used in many areas of Anatolia, including Gölyaka. Originally, this traditional plan was composed of two rows of rooms on both sides of a central living room, the Sofa. But in current practice, Sofa shrunk and was degraded into a wide corridor, instead of a living room, loosing much of its function and space quality. Nevertheless, this plan type as applied both in timber and reinforced concrete houses has some advantages against earthquake forces. Its symmetrical room arrangement around a central space provides walls with good resistance against lateral forces. This plan type can be rehabilitated with some other modifications like kitchen and bathroom cores with masonry walls. These walls can improve the rigidity of the timber frame. In any case, timber frame buildings especially in the high earthquake risk areas should not exceed two storeys, and should be constructed according to the building codes and manuals. In most of the timber frame houses, the walls are infilled with stone, mudbrick or brick that increases the weight of the building. Since the effect of earthquake increases with" the weight of the building, these traditional wall infill materials should be substituted with contemporary materials like light-weight building blocks, plastic or metal sidings. In the construction of exterior walls, attention should be given to Rain Screen Construction principles and detailing to avoid water penetration into the wall. Application of structural plywood sheeting on walls by means of glues provides stressed skin construction that has good resistance against lateral forces. The wide spacing of studs in traditional framing should be also reduced to intervals of 40-60cm that are extensively used in contemporary western applications. The standard sections of studs like 5x10cm should be properly applied in standard modules. The studs at corners and openings should be doubled or tripled. Thus, the standardization in building components and the modular arrangement of the studs provide faster and low-cost construction, Hence, the traditional heritage as observed in modular window arrangements should be re-evaluated for modern designs. The decorations on plaster or the joint design of masonry infill wall are the other aspects that can inspire modern designs. Traditional wooden lath wall construction has some advantages as it may prove to have higher resistance to earthquake. But, the plaster or stucco on laths can be changed to more resistant and durable compounds applied on metal or plastic laths. The floor construction can exploit various alternatives like platform, modified platform, independent floor and balloon framing. The first two systems are more appropriate forms of framing, and the spacing of the joists should follow the studs' intervals. The cross section of the joists should be checked according to the maximum allowable deflection which is between 1/300 or 1/360 of the span. Trussed roofs should be used instead of traditional hip roofs. Roof trusses provide better rigidity and stiffness and complement the wall and platform framing of the structural system. Heavy roof covering materials like baked earth roof tiles should be avoided, to reduce the total weight of the building. Instead, asphalt or metal shingles, or corrugated metal roof plates can be used for roof covering. Sandwich panels with heat insulation core are the other alternatives for contemporary roof applications. Traditionally, timber frame was built on masonry ground floor walls that rest on masonry foundations. These masonry walls protect timber from surface water, snow and termites. In contemporary applications, continuous foundations made of reinforced concrete can be used and even raft or pile foundations can be applied in high earthquake risk zones. Traditionally, connections between structural members like studs, walls and floor plates etc. are made by interlocking joints, which can also be observed in other timber construction cultures. In time, universally adopted methods of producing these joints introduced metal connectors like nails, screws, claw plates etc., which provide faster construction and less qualified labour. Many traditional joint designs have been devised to cope with specific structural needs, location in the building and exposure conditions. Some of these interlocking joints can be adapted to computer-aided manufacturing processes, as the advantages of these joints can be evaluated and joint carving culture can be transformed for modern needs. Some of the western countries have been evaluating other cultures' timber construction knowledge such as the outstanding Japanese timber craft. The missing items in the Anatolian timber heritage should be re-evaluated in the same manner with the know-how of these countries. One of the original timber building types of the local construction culture, is the serander, traditionally used as an ancilliary storage unit, which in the process of 'development' lost its conventional details and qualities. Instead, reinforced concrete columns are cast to bear an elevated timber storage space. The other traditional items not commonly used today any more are the built-in furniture like cupboards, seats, shelves etc. These precious features of the Turkish house were originally designed to meet the needs of daily life. Unfortunately, these items are substituted today by common furniture that can be found anywhere. The original space qualities are thus lost, and the community is alienated from its traditional furniture. Timber is a lightweight, environment-friendly material with features that goes well with standardization and modular coordination. Timber can be used both in industrialized building technologies like prefabrication, or in in-situ construction of the modified traditional systems. There is an important timber construction heritage in Gölyaka as in most of Anatolia. In order to harness this knowledge, the missing items should be rehabilitated with the contemporary materials and technologies. Timber frame construction also has advantages against earthquake forces, but special precautions should be taken against fire, moisture, water and wood-boring insects. In this rehabilitation process, while technology and knowledge of the global world is used, local cultural values should also be protected. Among these values are plan typologies, building images, decorations on facades, built-in furnitifres that evolved over centuries. These inherited items of the traditional construction should be incorporated within the contemporary materials and technologies for modern use.