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Study on Flat Roofing Systems 45 Journal of Advanced Sciences and Engineering Technologies Vol. 1, No.2 (2018) ISSN: 2617-2070(Print) ;2617-2070 (Online) Journal of Advanced Sciences and Engineering Technologies Available online at: http://www.isnra.com/ojs/index.php/JASET/ Invest Bassam Abu Awwad 1 Manal O. Suliman2 Study on Flat Roofing Systems 1Department Of Architecture, College of Engineering, Jaresh University-Jaresh- Jordan *E-mail of the corresponding authors: [email protected] , 2 Civil Engineering Department, College of ABSTRACT Engineering, Jerash University, Jerash, Jordan * E-mail [email protected] Keywords: In many Buildings, the roof is a major element that gives Journal of Advanced Sciences and Engineering Technologies the Building its distinctive profile .The main purpose of a Flat roof roof is to protect the Building or the house in all types of Green Roof weather with a minimum of maintenance .a roof must Be Unventilated roof Ventilated roof strong to with stand snow and wind loads. Another consideration is appearance .a roof should add to the ARTICLE INFO attractiveness of the Building roof styles are used to create different architectural effects. This paper reports Article history: a study on flat roof systems include the layers of Received 01 august 2018 Accepted 20 august2018 structural elements of the roof, types of finish used, AvailaBle online 10 OctoBer 2018 flashing, roof edging, drainage, and other details associated with the roof. Journal of Advanced Sciences and Engineering Technologies DOI: https://doi.org/10.32441/jaset.v1i2.120 © 2018 JASET, International Scholars and Researchers Association 46 Bassam Abu Awwad. et al.. / Journal of Advanced Sciences and Engineering Technologies Introduction Layers of Structural Elements The roof is a system that separates the Flat roofs can have various functional layers building's top floor from the outdoor matched to each other. It is essential that environment. A roof consists of a set of load- the layer sequence provide adequate bearing and protective elements that intend insulation against heat and noise. The to protect the interior of Buildings from moisture to which the structural layers are meteorological phenomena such as rain, exposed [4,5].(e.g. trapped humidity, heat, cold, wind and snow, sheltering the condensation Build-up) building's structure and ensuring high standards of living conditions. The rooftop Under course is, By definition, the highest floor of the The course below the waterproofing which building and may be pitched or flat, with a deals with water is called the under course. structural and/or coating function. The roof It can Be the load Bearing structure, e.g. a of a Building is undouBtedly the envelope concrete surface, or also Boarding or the element that most influences the thermal insulation component. It is performance of this type of construction, important that the waterproofing material because it protects the interior from bad match the under course, to avoid expansion weather and solar radiation and guarantees cracks, for example. thermal comfort inside the Building. Flat roofs have had, over the last few years, a Bonding course wide application in many countries, following the architectural evolution, the Bonding courses are installed to improve emergence of new materials, and the the adhesive properties of Building improvement in the performance of the component layers. These can Be primers or existing ones. The success of this solution is prior applications of bitumen solutions and related to it Being quickly executed (in bitumen emulsions. Bonding courses are favoraBle weather) and providing a useful painted, rolled or sprayed on to a clean area for the Building. [1,2] under course. Flat roofs are a key Building element to Leveling course ensure water tightness (water and steam) of If layers of components turn out to Be the external envelope of Buildings, and uneven or rough, a leveling course may be represent one of the areas where a needed. This compensates for component significant part of thermal exchanges with tolerances, creates a smooth surface and is the exterior occurs. Moreover, the Behavior supplied as Bitumen roofing sheet, glass or of an individual flat roof at the top floor of a plastic fleece, and as foam mats. It is laid building, and that of the whole building, is loose or spot-glued. conditioned By the Better or worse performance of this building assembly [3] . Separating course Separating layers or courses are laid to insure that adjacent layers of structural elements with different expansions properties can move in relation to each other, or to accommodate other mechanical 47 Journal of Advanced Sciences and Engineering Technologies Vol. 1, No.2 (2018) movements. They can also Be used if two Such layers, like vapor Barrier may consist materials are chemically incompatiBle. of Bitumen roof sheeting, plastic vapor barrier sheeting, elastomer roof sheeting or Vapor barrier compound foils. They are laid loose or spot- Vapor barriers are used to regulate glued moisture transmission inside the Building. Roof waterproofing They are not waterproof, but simply inhibit vapor diffusion. The inhabitation factor The water-bearing course is created by the indicates how much moisture can diffuse roof waterproofing. It is a closed, through the vapor Barrier. They can Be waterproof area and can be produced with bitumen roofing sheets, plastic vapor bitumen roof sheeting, plastic or elastomer inhibiting sheets, elastomer roofing sheets, sheeting or fluid-applied waterproofing. The or compound foils. They can Be laid loose or waterproofing must Be at least 1.50 mm fit, spot-glued. Points at which the individual at least 2.00 mm for used roofs. sheets meet must Be fully glued. The vapor Barrier must extend to the top edge Filter course insulating course and Be fixed there at roof A protective or filter course is used to edges and penetrations. protect the waterproofing from mechanical Thermal insulation influences. PVC, ruBBer or plastic granulate highly perforation-proof sheets, drainage Thermal insulation protects the building mats, or sheets of extruded polystyrene from heat loss in summer, and prevents foam are used. large thermal Build-ups through insulation in summer (summer thermal insulation). Surface protection Expanded polystyrene (EPS), extruded Modern foil roof are installed as single- polystyrene (XPS), extruded polyurethane layer waterproofing courses and attached to (PUR), mineral fiBer insulating material the course Below with strips that are glued (MF), foam glass (FG), cork, wood fiBer on suBsequently, or spot-attached. They are insulation material, or expanded usually made of light-colored materials, so bituminized mineral infill may be used. The that thermal expansion as result of sunlight thermal insulation can also Be used to is minimized. Because of their material create a roof drainage incline [6]. properties they offer adequate protection Sheet insulation should Be laid with an from UV radiation. No additional surface offset and joints are as tight as possiBle. The protection need to be used for foil roofs. insulation is glued to the surface Below and This saves weight, and the roof the sheets are attached to each other waterproofing does not provide adequate according to the manufacturer’s protection against UV radiation, wind instructions. upthurst or mechanical loads. A light surface protection is provided for Bitumen Vapor pressure compensation course sheets according to load. This can Be achieved By applying sand, for example. A vapor pressure compensation course is Crushed slate is sprinkled into cold polymer fitted to distribute the water vapor pressure bitumen compound and attached to the evenly in the roof water proofing material. bitumen sheeting [7] 48 Bassam Abu Awwad. et al.. / Journal of Advanced Sciences and Engineering Technologies Gravel surface protection courses are Sufficient spacing should Be maintained at known as heavy surface protection. The the edges to prevent the raised gravel later should Be at least 50 mm thick waterproofing from damage. AccessiBle when installed. The weight of the stones can coverings can Be laid in the form of small prevent unfixed roof covering being lifted slaBs in Bed of mortar on a tufted mat or by wind suction. If the surface is protected drainage course. The mortar should Be with crushed stone or gravel, care should Be approx. 4 cm thick. Spot Bedding is taken that the grain size Be sufficient By the recommended for larger slaB coverings. material not to Blow away in the wind. A Prefabricated height-adjustable elements sheet covering is preferaBle for surfaces can compensate for tolerance here. exposed to strong winds. Compression-proof thermal insulation, such as foam glass, should Be used to prevent the Accessible Coverings adjustable elements punching holes in the AccessiBle coverings, i.e. coverings that can roof waterproofing. A more simple method be walked on, can also be used to protect is to lay the covering on little Bags of the surface. In such cases a compression- mortar. For this, fresh mortar is packed into resistant thermal insulation course should little plastic sacks, they can Be leveled to be installed. The roof waterproofing must compact the mortar completely. The cavity be adequately protected against mechanical under the slabs maintained and the slaBs influences. If the joints Between the slaBs are not Bedded directly on they are sealed, or the entire covering is closed, a waterproofing, large slaBs should Be laid in slope of at least 1% must Be created. a Bed gravel for Better weight distriBution. Drainage is then maintained on the Here the gravel Bed is approx. 5 cm thick. waterproofing, and it Becomes the water- The gravel selected should allow any bearing course. The slabs chosen must be accumulated precipitation water to drain off frost proof. Expansion joints should Be freely [7,8] provided to allow for thermal expansion. 49 Journal of Advanced Sciences and Engineering Technologies Vol. 1, No.2 (2018) Fig .1 AccessiBle Coverings Green Roof Plants can also be used to protect the be installed.
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