Teras çatılarda kullanılan pestil ve sıvı şeklindekisu yalıtım malzemeleri ve uygulamaları
Watertight insulating materials for flat roofs in the form of membranes and liquıds and their applications
Yazar: SİBEL MÜTEVELLİOĞLU
Danışman: PROF. DR. EROL GÜRDAL
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü
Derece: Yüksek Lisans, 1994
Konu: Mimarlık = Architecture
Dizin: Bina bilgisi = Building information ; Su yalıtımı = Waterproofing insulation ; Teras çatılar = Flat roofs ; Yapı malzemeleri = Building materials

Özet:
Teras çatılarda kullanılan pestil ve sıvı şeklindeki su yalı tım malzemelerinin ve uygulamalarının ele alındığı bu çalışmada, bitümlü malzeme, plastik malzeme ve polimer bitümlü malzeme genel özellikleri, teras çatılarda kullanım şekilleri ve uygulamalarıyla anla tılmıştır. Birinci bölümde çalışmanın amacı ve kapsamı belirlendik ten sonra, ikinci bölümde, çok eski dönemlerden yakın zamana kadar gelen süreçte, su yalıtımında kullanılan tek malzeme olarak kabul edi len bitüm ve bitümlü malzeme genel özellikleriyle anlatılmıştır. Üçün cü bölümde, bitüm ve bitümlü malzemenin teras çatılarda su yalıtımın da kullanılma şekilleri yer almıştır. Dördüncü bölümde, su yalıtımında kullanılan, yeni bir mal zeme olarak kabul edilen plastik malzeme genel özellikleriyle anlatıl mıştır. Beşinci bölümde ise plastik malzemenin teras çatılarda su yalıtımında kullanılma şekilleri belirtilmiştir. Altıncı bölümde, bitümün uygulama özelliklerini iyileştir mek amacıyla oluşan polimer bitümlü malzemeler genel özellikleri ve uygulama şekilleriyle yer almıştır. Yedinci bölümde ise, bitümlü, plastik ve polimer bitümlü malzemelerin ele alındığı bu çalışmada, başarılı uygulamalar elde ede bilmek için dikkat edilmesi gereken noktalar belirtilmiştir.

Abstract:
Roofs, which are regarded as finished structural elements, are completely subject to atmospheric conditions. In order to fulfil their function, roofs, no matter what degree of slant they have, should provide protection against the problems of water, heat and humidity which we call atmospheric conditions. Although slanting roofs provide more protection against the problems mentioned, this type of roofs have been gradually replaced by flat roofs because the space lost in slanting roofs has been regained through use of flat roofs. Therefore, use of flat roofs has made the problems referred to more obvious. The most remarkeable problem is water. The fact that flat roofs have a small degree of or no slant at all has doubled the importance attached to this problem. Accordingly, the purpose of this study is to become familiarized with watertight (impermeable) materials and establish the conditions of their application. Before proceeding to impermeable (watertight) insulating materials, used in flat roofs, let us list the qualities these materials are expected to have.. The materials must be absolutely watertight,. Must be elastic,. Must maintain their proporties at a wide rage of temperatures,. Must not trickle in hot weather and break at low temperatures,. Must not be deformed when exposed to chemical factors,. Must be resistant to ultraviolet rays,. Must be easy to apply, IX. Must be adaptable to any kind of details,. Must be applicable to any kind of flooring material,. Must firmly hold the surface to which they are applied,. Must consist of only one piece or the joints must be as strong as other parts,. Must be resistant to weights applied on them,. Must not conduct electricity,. Must be durable,. Must be economical. The oldest and what we can describe the only material which has been used in insulating roofs against water is bitumen and materials with a bitumen base. Bitumen and bitumen-containing materials are black building materials with a hydrocarbon base which are derived from crude oil and coal. Hydrocarbons are formed as a result of chain combination of many carbon and hydrogen elements and the compounds are converted into mixtures in the form of colloids and suspensions. Bitumen materials are divided into asphalt and tar according to their nature and the way they are derived. Although the material in the asphalt category occurs freely in nature, it is also derived from crude oil. Natural asphalt is grouped into rock asphalt and lake asphalt. Rock asphalt is naturally chalk saturated with bitumen. The bitumen content of rock asphalt is 10%. Lake asphalt consists of mineral substances in the form of very fine grains scattered in bitumen. In this type of asphalt, the bitumen content is 55%. Use of lake asphalt in structures is only possible when they have the desired form after the refinement. The by-products derived from crude oil are rich in bitumen. Therefore, this kind of bitumen is used in insulation. Asphalt derived from crude oil contains more than 99% bitumen. This asphalt is called asphalt cement. Moreover, oxidized asphalt is produced by blowing air through the remnant asphalt. The materials in the tar group are produced by dry-heating natural organic substances such as wood and coal in an airtight environment. These materials are usually used in road coverings. Bitumen materials occur in the form of solids andsemisolids (asphalt cement, oxidized asphalt, coal tar), liquids (cutback asphalt, emulsion asphalt, tar) and modified materials. The main reason for bitumen materials being used in roofs is their property being water and dampproof. Bitumens materials are applied to flat roofs in the form of bitumen mixtures and coverings. Bitumen mixtures cover mastic asphalt and bitumen mortar. Mastic asphalt is produced by mixing asphalt cement, oxidized asphalt and mineral aggregate in the right proportions and baking them in special furnaces. Its bitumen content is 12.20%. At 205°C it is in the form of plastic and runny. Bitumen mortars occur in the form of hot-mixed and cold-mixed mortars. Hot-mixed mortars are produced by heating the right proportions of coal tar, asphalt cement with a low penetration of 40-50%, oxidized asphalt and mineral aggregate to 150°-190°C in different furnaces to form a mixture. Cold-mixed bitumen mortars cover bitumen solutions and emulsions. Materials in the form of bitumen mixtures are applied in two layers 1 cm each and a protective layer of 3,5 cm in thickness is placed on them. Bitumen coverings are classified into insulating coverings with organic armatures and those with inorganic armatures. Insulating coverings with organic armatures have a plant and animal base. These coverings include cotton and jute canvas, felted wood pulp and cardboard. Organic insulating coverings have some adverse proporties: They undergo a limited expansion when subjected to heat, contain damp, are affected by microorganisms and do not have a high resistance to ultra violet rays. Coverings with inorganic armatures contain armatures with an inorganic base. These include asbestos, glass woven, glass tulle, polyster felt and metallic fibers. Insulating coverings with inorganic armatures are resistant to chemical and physical effects, are not affected by microorganisms and ultraviolet rays, clo not cause the bitumen to become dry and do not undergo deformation due to damp. Bitumen coverings are applied between the lining layer and the protective layer spread according to the function of the roof area. Another material that we can regard as new used in flat roofs for the insulation against water is plastic. Plastic materials which we can describe as polymers and macromolecules are artificial materials which are produced through the transformation of synthetic or organic substances with a high molecular weight and occur in the solid or any form required. xiPlastic materials are made up of polymers which are formed through the combination of small molecules called monomers in different ways. Plastic materials are divided into thermoplastics and thermoset plastics according to their behaviour towards heat. Thermoplastics can soften without any change in their composition when subjected to heat, can maintain their shape when cool and can theoratically repeat this cycle for ever. Their macromolecules are in the form of fibers or series. The chemical reaction during the production is speedy and occurs in only one stage. They are given the desired shape during the production. When subjected to heat, they reach the desired softness and can be given any shape. They maintain their shape when cool. If exposed to a high temperature, they soften and melt and if the exposure is prolonged, they decompose and burn. As they have the liquid form at high temperatures, they weld well and be cut smoothly Thermoset plastics cannot soften and be shaped when subjected to heat and are carbonized without melting when subjected to a high temperature, in other words, they decompose. Their molecules are combined crosswise and resemble tight knots. The chemical reaction during the production does not occur in one stage. First, short fibers occur and then they turn into a ball. The chemical reaction is stopped at the point where it can be started again. The plastic is taken from the place it is produced as a half-finished product and shaped separately in a required place and at a required time. Thermoset plastics don't lose their final shape but cannot be given a different shape after they have been produced in a definite shape. If exposed to too high a temperature, they decompose without softening and melting. They don't weld well enough and they don't allow smooth cutting. When they are cut, they crumble. It is only through recent developments that plastic materials are used in the insulation against water. This material has a wide range of applications not only because it provides insulation against water and is easy to apply, but also because of its dimensional determination, its resistance to aging, its capability to weld, its resistance to heat effects and its mechanical resistance. Plastic materials are applied in flat roofs in the liquid form or in the form of membrane. In the case of the liquid form, solutions or liquid mixtures with quite a low viscosity are used in the material. The most common liquids and mixtures are materials such as neoprene, polyurethane, vinyl resines and acrylic. This type of materials make jointless insulating material. Such matrials stick very xuwell to the surface where they are applied, are elastic, resistant to acids and alkalis, have resistance to ultraviolet rays and are easy to apply. The application of plastic insulating materials is carried out with a brush or by spraying. A final protective covering is played on them according to the desired function. The application of plastic membranes is carried out by joining and welding the edges together and spreading them as a single piece. The most important point to be put into consideration in the insulation against water with plastic materials in the form of membranes is that the plastic membranes has the required resistance and thickness. The plastic membranes in common use are PVC, EPDM, Polysobutylenes and others. This kind of membranes have a high resistance to heat. They are not affected by ultraviolet rays and ozone, do not wear out, do not decompose and displays a high chemical resistance. Their application is very easy (They are easy to apply). They are not adversely affected by atmospheric conditions during the application. This kind of materials are applied in a single layer as a single piece followed by a protective layer according the function it is expected to fulfil. Another material used in insulation of flat roofs against water is polymer-bitumen which is produced by combining bitume and plastic materials. Polymers in bitumen, which melt at high temperatures and take shape at lower temperatures, are preferred due to their elasticity given by their long macromolecules. As a result, polymer-bitumen mixtures are formed. These materials have considerably improved the physical and mechanical characteristics of bitumen. Its softening point has increased, its resistance at low temperatures has increased, as well as its mechanical resistance and its resistance to external atmospheric conditions. On the other hand, its penetration has decreased. Polymer-bitumen materials developed in this way are applied in the insulation of flat roofs against water in the form of liqued or membranes. Liquid polymer-bitumen materials incorporate the superior properties of elastomeric resins and polymer-bitumen derivatives. Polymer-bitumen, which have superior proporties, is used in the formation of insulating materials in the form of membranes are grouped into plastomeric polymer bitumen and elastomeric polymer-bitumen substances. Plastomeric polymer-bitumen coverings are impermeable coverings which have inorganic carriers, are xiumodified by APP and other thermoplastics and are covered with a polymer-bitumen substance. Their upper and lower surfaces are liable to melt. Plastomeric polymer-bitumen coverings are applied with the oxy-acetylene burner flame. Elastomeric polymer-bitumen coverings are impermeable coverings which have inorganic carriers, are modified by SBS and other thermoplastics and are covered with elastomeric polymer-bitumen. Its upper and lower surfaces are covered with a film liable to melt and applied with the oxy-acetylene burner flame or hot asphalt. Application with this kind of materials are carried out in layers and a protective layer is placed over them according to the function to be fulfilled. In this study which deals with the materials used in the insulation of flat roofs against water, it can be concluded that the problem of the insulation of flat roofs against water should be solved correctly in terms of the health of structures and users using the right materials and application methods. Although the insulation of flat roofs against water represents a small proportion of the cost, it is a necessary process in order to prolong the lifespan of roofs, to prevent the deterioration of materials and to avoid any harm to users. An efficient process of insulation against water involves a thorough familiarization of materials and right applications. The application criteria can be summarized as follows:. The material to be used should meet the standards.. Before the material is used, the application surface should be cleaned, dried and made smooth.. Alining layer should be applied to the finished surface.. The bitumen material to be used should be compatible with the hygrotermic conditions of the environment.. Oxidized or modified bitumen should be used.. In the application involving bitumen coverings, the edges of the covering should not overlap and there should be enough clearance between the edges. Plastic coverings should be joined using plastic sticking plasters without overlapping them.. In the applications involving insulating mixtures the layers should be applied after each layer has dried enough.. Plastic coverings should not be strained before they are stuck.. In places where there is a wide range of temperature differences, the coverings should be stuck partially rather than completely, or spread freely.. The materials should cover the impermeability area xivsecurely.. A protective layer should be placed on the materials according to their type and the function of the roof area.. After the application, maintenance and repair work should be conducted at regular intervals. In brief due consideration should be given to a successful insulation of roofs against water using the correct materials and details and carrying out right applications.