Styrodur C Europe s green insulation. Roof Insulation

Transcription

1 Europe s green insulation Roof Insulation 1

2 1 Thermal Insulation 3 2 Flat Roofs Types of Flat Roofs/Definitions 6 3 Advantages of Inverted Flat Roofs Advantages of Styrodur C in Inverted Flat Roofs 9 4 Applications Substructure Roof Sealing Roof Drainage Thermal Insulation Layer Protective Layer Inverted Gravel Roofs Duo Roofs Plus Roofs Green Roofs Roof Terraces Parking Decks 25 6 Technical Data Styrodur C 31 Contents Overview 2

3 1. Thermal Insulation is BASF s environmentally friendly, extruded polystyrene rigid foam. It is free of CFC, HCFC, and HFC and makes an important contribution toward reducing emissions of carbon dioxide (CO 2 ). Due to its high compressive strength, low moisture absorption, durability, and resistance to decay, Styrodur C has become synonymous with XPS in Europe. The compressive strength is the main distinction between the various Styrodur C types. Effective thermal insulation with Styrodur C reduces energy consumption with the result that the investment in thermal insulation can be offset within a short period of time. It makes for healthy and comfortable living and protects the building from the effects of moisture as well as high and low temperatures. Styrodur C is manufactured in accordance with the requirements of the European standard DIN EN In terms of fire protection, it has been classified as Euroclass E in accordance with DIN EN It is qualitycontrolled by Wärmeschutz e.v. and has been granted the approval no. Z by the DIBt, an institute of the Federal and Laender Governments for a uniform fulfillment of technical tasks in the field of public law. Kitchen Bathroom Conservatory Patio Living area Work area 31 Styrodur C Thermal Insulation 3

4 2 Flat Roofs 2. Flat Roofs Although the style and materials chosen for covering and sealing flat roof constructions have a high architectural significance, it is not solely the creative aspect that shapes the characteristics of a building. Apart from the building s functionality, economical aspects as well as structural design play a big part in choosing the right style, shape, and material for a roof. Regardless of any specific demands, flat roofs can meet the requirements of building physics and construction just as well as pitched roofs. According to the current standards and regulations for thermal insulation, the composition of layers for flat roofs as well as for roofs with varying inclinations provide long-term reliable protection against the effects of the weather. Therefore, the security of a roof does not depend on the water-bearing layer s grade of inclination but rather on how well the planning and execution comply with the special requirements of the construction. In contrast with the conventional warm roof with its roof sealing above the thermal insulation, special insulation materials like BASF s allow the developer to invert the layers. Such inverted roofs being the number one choice of a growing number of planners, BASF s Styrodur C makes for the ideal thermal insulation. This brochure provides all the necessary information with regard to the planning and construction of inverted roofs and explains their advantages over conventional warm roofs. Fig. 1: Prestige object: For the reconstruction of the Water Tower in Hamburg, the roof is being insulated with. The thermal insulation of inverted roofs is subject to high compressive stress caused by rainwater, the soil of the roof s greening, or the loads of traffic on parking decks or roof terraces. Therefore, it must exhibit high resistance to moisture and decay. Since it is already being stressed during installation, e. g., by construction workers and light machinery such as wheelbarrows, and because it is installed directly below the covering or the ground, it must ensure high compressive strength. Moreover, it has to provide solid and long-lasting thermal insulation to fulfill the actual functions of an inverted roof. Styrodur C is sturdy and easy to handle. It meets all of the requirements mentioned above. During the extrusion process of the thermal insulation boards, a clean, even, and compressed foam membrane is formed on the surface, which makes the boards resistant to the effects of the weather. The boards feature a rabbet edge profile all around, so as to avoid the formation of cold bridges when they are joined. Fig. 2: Due to its high compressive strength and low thermal transmission coefficient, Styrodur C is the perfect choice for inverted flat roof constructions. Due to its diverse characteristics, Styrodur C is extremely versatile, which is why BASF provides a range of various types. Index 1 specifies the main differences of all Styrodur C types suitable for inverted roofs, the most important being compressive strength and thermal conductivity. The different types of Styrodur C are specified in Index 2. For inverted-roof constructions in accordance with the German standard DIN , choose the right l value from Index 3. If the roof is designed as a green roof or inverted roof, consideration must be given to approval number Z Heat insulation must be demonstrated following the rated values of the DIBt approval, depending on the thickness of the thermal insulation (see Index 3). 4

5 Index 1: Technical data of types for inverted roofs Properties Unit Code in accordance with DIN EN CS 4000 CS 5000 CS Standard Compressive strength or compressive stress at 10% deformation kpa CS(10\Y) DIN EN 826 Allowable long-term compressive creep; 50 years kpa CC(2/1.5/50) DIN EN 1606 compression < 2% Deformation behavior 20 kpa; 80 C Deformation behavior 40 kpa; 70 C Long-term water absorption by immersion % DLT(1) DIN EN 1605 % DLT(2) DIN EN 1605 % by vol. WL(T) DIN EN Long-term water absorption % by vol. WD(V) DIN EN by diffusion Freeze-thaw resistance % by vol. FT DIN EN Index 2: Types of Styrodur C Unit 3035 CS 4000 CS 5000 CS Edge profile Surface skin skin skin Thickness mm T1 30/40/50/60/ 30/40/50/ 40/50/60/ 80/100/120/ 60/80/ 80/ /160/ /120 Length x width mm 1,265 x 615 1,265 x 615 1,265 x 615 Index 3: Thermal conductivity of Styrodur C Thickness (mm) l D [W/(m. K)] R D (m 2. K/W) l [W/(m. K)] l B l D = Thermal conductivity in accordance with DIN EN R D = Surface resistance in accordance with DIN EN l = Thermal conductivity in accordance with DIBt approval no. Z , in line with DIN l B = In accordance with DIBt approval no. Z for inverted roofs designed as green roofs or parking decks Z Flat Roofs 5

6 Types of Flat Roofs/Definitions 2.1 Types of Flat Roofs/Definitions According to German standard DIN 18531, roofs belonging to Inclination Group I (> 3 ; 5%) and Inclination Group II (between 35 ; 59%) are defined as flat roofs. The inclination of the roof significantly influences the type and design of the chosen roof insulation. According to the guidelines of the German Roofing Contractors Association (ZVDH), depending on their design, roofs are classified into ventilated and nonventilated/warm roofs. On nonventilated flat roofs, all layers are installed directly on top of each other. If these layers are glued onto each other, the design is called a compact roof. Depending on their use, one distinguishes between utilized and underutilized space. Underutilized space is only walked on for maintenance purposes. For the construction of underutilized spaces, see German standard DIN Utilized space is designed for use by people and traffic, as well as for intensive or extensive greening. The guidelines for flat roofs therefore distinguish between: The old requirements for applications of polystyrene rigid foam, which were defined in the German standard DIN (application type WD compressive stress and application type WS high compressive stress), have not been implemented in the new European standard DIN EN Application requirements for thermal insulation are specified in standard DIN V , in which the inverted-roof construction is classified as DUK. Minimum requirements concern: thickness tolerance, maximum allowable deformation for predefined compressive stress and temperature, compressive creep, water absorption by diffusion, and freeze-thaw resistance, as well as compressive strength at 10% deformation for three categories: a) dh (min. 300 kpa) for high compressive strength, b) ds (min. 500 kpa) for very high compressive strength, and c) dx (min. 700 kpa) for extremely high compressive strength. Depending on the position of the insulation layer, the unventilated roof is either known as a warm roof or an inverted roof. Both types can be designed for utilized or underutilized flat roofs. See the basic design in Fig. 3. Roof terraces Parking decks Green roofs (extensive or intensive) For the construction of utilized spaces, see German standard DIN According to guidelines for flat roofs, polystyrene rigid-foam insulation boards with average compressive strength should be used for underutilized flat roofs, while for utilized flat roofs one should use rigid-foam boards with high compressive strength. All types usable for inverted roofs meet those requirements according to Index 1 (page 5). Gravel Geotextile Thermal insulation 2 Flat Roofs Warm roof Fig. 3: Comparison between warm and inverted roof. Vapor barrier Reinforced concrete pavement Inverted roof 6

7 Types of Flat Roofs/Definitions A warm roof is a nonventilated roof with a weatherproof roof sealing on top of the insulation layer. However, there are three different types of inverted roofs: The most common is the standard inverted roof, with the thermal insulation layer consisting of one layer of extruded polystyrene rigid foam installed solely on top of the roof sealing. All three types can be implemented for graveled roofs, roof terraces, green roofs, or parking decks. While the applications are modified, the principle of inverted-roof design remains unchanged. According to the German standard DIN , the inverted-roof design is applicable for graveled roofs as well as for roof terraces. Only green roofs and parking decks need approval from building authorities, which is available for Styrodur C (DIBt approval no. Z ). The so-called duo roof has a second insulation layer on top of the conventional warm roof and the roof sealing. This design is most common for new buildings. Depending on the climatic conditions, there is no need for a vapor barrier. The plus roof is a solution for the reconstruction of flat roofs that are not sufficiently insulated. It is also an option if the advantages of a warm roof are to be combined with those of an inverted roof. In this case, an inverted roof with XPS insulation boards is installed on top of the warm-roof construction, e. g., with EPS insulation, in order to protect the roof and improve its durability. More precisely, a thermal insulation layer of Styrodur C is subsequently installed on top of an existing warm-roof construction whose roof sealing has previously been checked. Fig. 4: Prestige object: Office building close to the Hong Kong Airport with. 2 Flat Roofs 7

8 3. Advantages of Inverted Flat Roofs An inverted flat roof consists of the following layers: Protective layer (e. g., gravel) Geotextile (optional), e. g., polyester or polypropylene mat insulation layer acting as a vapor barrier Leveling course Reinforced concrete pavement The inverted roof is easier and quicker to install than a regular warm roof because it consists of fewer layers to be laid and glued. On an inverted roof, the sealing, a very important layer, is installed directly on top of a solid, massive surface free of grooves, with the exception of the plus roof and the duo roof. In case of mechanical strain, the sealing can directly transfer the occurring stress. However, if an insulation layer is installed, little grooves may form between the various layers of insulation boards and the sealing could lag in those grooves, which may lead to cracks. The vapor sealing of inverted-roof constructions should contain a water-vapor transmission layer that is at least 100 mm thick to reduce the water-vapor diffusion through the roof construction while keeping the transmission from changing direction during the summer and letting moisture inside the building. Because the roof sealing of an inverted roof is installed below the thermal insulation layer and the covering (e. g., gravel or pavement), it is permanently protected from ultraviolet rays. Depending on the structure, the roof sealing of conventional warm roofs may be exposed directly to the sun s UV rays, which can cause damages in bituminous as well as plastic sealing designs. In addition, the thermal fluctuations of the roof sealing are less significant in inverted-roof designs. Thermal fluctuation on the membrane can be up to 110 K during the course of one year in the case of a conventional warm roof, while it only reaches 12 K in inverted roofs with room temperatures of 20ºC below the roof. 3 Advantages of Inverted Flat Roofs If the sealing is glued onto the complete surface of a massive concrete pavement, any potential leakages can be detected easily. The water will leak at the exact spot on the inside where the sealing is damaged. This is not the case with a conventional warm roof: if the water leaks through the sealing, the visible damage caused by the water will often appear far from the leakage. There must also be absolutely no moisture between the vapor barrier and the roof sealing, which can be difficult to ensure. When installing a warm roof, it is important for the thermal insulation boards stored on the construc tion site to be protected from humidity at all times and that the installed boards are covered. As a rule, the insulation boards are not to be installed in rain or fog, or else the embedded moisture below the roof sealing will cause steam bubbles. However, when constructing an inverted roof, the insulation boards can also be installed under rainy conditions. The water can simply diffuse through the Styrodur C thermal insulation layer or evaporate through the butt joint into the ambient air. 8

9 Advantages of in Inverted Flat Roofs Warm roof without gravel Warm roof with gravel Inverted flat roof C Mechanical damages UV rays C Mechanical damages UV rays Mechanical damages UV rays C Fig. 5: The thermal insulation protects the underlying roof sealing from thermal fluctuation, thermal shock, and mechanical damages. Fig. 5 illustrates the everyday strain of thermal fluctuations on the roof sealing within a conventional warmroof design without gravel, as opposed to an inverted flat roof. During the summer, temperatures on the warm roof sealing can rise up to 70ºC whereas temperatures are nearly stable if an insulating layer protects the roof sealing, as is the case with an inverted roof. Thermal shocks, e. g., caused by hailstorm during the summer, cannot damage the sealing of an inverted roof. The roof sealing of a conventional warm roof is constantly exposed to mechanical strains. Much damage already occurs during construction on top of the roof, caused by the storage of materials, falling objects, etc. In the case of inverted flat roof constructions, the viscoplastic thermal insulation layer both protects the roof sealing from mechanical strains and acts as a protective layer as required according to German standard DIN C Summer Winter Time of Day Fig. 7: Thermal stress on a warm roof and an inverted flat roof. C Summer 20 0 Winter Time of Day 3.1 Advantages of in Inverted Flat Roofs is commonly used for the construction of inverted flat roofs since the 1970s and has been approved by building authorities since Samples from functioning inverted-roof constructions have shown that the mechanical and physical properties of Styrodur C given below remain virtually unchanged throughout extended periods of time (Fig. 6). Fig. 6: Sampling from a ten-year-old inverted green roof. Warm roof without gravel Warm roof with gravel Inverted flat roof C Summer 20 0 Winter Time of Day 93 Advantages of Inverted Flat Roofs

10 Advantages of in Inverted Flat Roofs Water resistance: Due to its closed-cell foam structure and the double-sided foam membrane, the insulation boards hardly allow any water to permeate. The moisture content of boards that have been lying underneath graveled roof constructions for many years was approx. 0.1%, which hardly affects the thermal insulation boards in any way. These requirements became law with the German standard DIN , which also specifies that protective layers may additionally be a useful layer for the building, e. g., the thermal insulation layer also acts as a protective layer for the roof sealing. Styrodur C 3 Advantages of in Inverted Flat Roofs Hohe Festigkeit: eignet sich durch seine Festigkeitseigenschaften ideal als Dämmstoff für UK- Dächer. Für besonders stark be lastete Dämmstoffe, beispielsweise beim Parkdach, empfehlen sich die außerordentlich druckfesten Typen Styrodur 4000 CS und 5000 CS. Brandschutzklassifizierung: ist im Brandverhalten in die Euroklasse E nach DIN EN (Brandverhalten von Baustoffen) eingestuft. Die bauaufsichtliche Zulassung lautet Z Fig. 8: is extremely resistant to water due to its closed-cell foam structure. Dimensional stability: The extrusion process as well as the controlled storage of the material before dispatch guarantee a very high dimensional stability. The material is resistant to deformation at loads and temperatures as defined in DIN EN Cold bridges: No cold bridges will form when installing Styrodur C boards with all-around rabbet edges. Handling: In order to process the Styrodur C boards, you will only need the tools usually required for woodwork. Connections and cutouts can be easily handled with clean-cut edges that will not crumble. Constructing an inverted flat roof basically results from the requirement to protect the roof sealing from all static, dynamic, and thermal influences. Can take on static functions and transmit all occurring loads due to its high compressive modulus of elasticity. Can uncouple the superstructure and the substructure including the supporting structure and the roof sealing due to its viscoplastic yet solid structure. Helps save heating and cooling energy and protects the building from intense climatic conditions. These properties of Styrodur C make it easy for the planner to decide in favor of an inverted flat roof when building heavily strained flat roof constructions. 10

11 Substructure n Roof Sealing n Roof Drainage 4. Applications 4.1 Substructure The inverted flat roof as a thermal insulation system is applicable for unventilated flat roofs with heavy as well as light substructures, as long as the following requirements are met: Heavy substructures like massive ceilings must have a mass per unit area of 250 kg/m 2. Light substructures with a mass per unit area of less than 250 kg/m 2 must show a surface coefficient of 0.15 m K/W. The high mass per unit area and the required surface coefficient of the substructure shall protect the ceiling s underside from condensation in the case of cold rain. Areas on which roof sealing is to be installed must be clean and free of foreign substances. Concrete pavements or sloping concrete must be sufficiently solid and dry on the surface. The dimensional tolerance according to German standard DIN and the Guidelines for flat roof constructions must be met. Inverted flat roofs with do not need an incline. Although small amounts of water will remain on the flat roof after rainfall, this does not affect the functionality of the inverted flat roof as long as they do not permanently flood the insulation boards. Attention: Tar-bitumen roof sheeting or any solvent-based sealing is not suitable for the construction of inverted flat roofs using Styrodur C. 4.3 Roof Drainage Because the membrane is installed underneath the insulation layer, drainage must occur above and below the insulation boards. This is why a roof intake with two drainage levels (Fig. 9) is necessary. The requirements for the professional installation of those intakes should be clarified in advance in order to prevent the Styrodur C boards from being constantly under water as a result of the intakes being too high. Depending on the application, inverted flat roofs require roof intakes per m 2 as specified in Index 4. Index 4: Diameter of roof intake dependent on the application and the surface of the flat roof. Diameter of Surface (m²) of: roof intake Ø in mm Flat roof < 15 Graveled roof Green roof Roof Sealing For inverted-roof designs with an incline of more than two percent, all conventional sealing materials are suitable: Bitumen roof sheeting Polymer-modified bitumen sheets Plastic sheeting High-polymer plastic sheeting Inverted flat roofs with an incline of less than two percent are special constructions and require specific provisions to avoid risks from standing water. That is why in the case of bituminous sealing, there must be either two layers of polymer-modified bitumen sheets or two layers of bitumen roof sheeting. If the roof sealing is made from plastic sheeting, the membranes need to be accordingly thick. In any case, we suggest referring to the manufacturer s processing specifications or the Guidelines for flat roof constructions. Gravel seeping layer Geotextile Reinforced concrete pavement Roof outlet Fig. 9: Roof intake with two drainage levels for the drainage of surfaces above and underneath the insulation layer. 4 Applications 11

12 Thermal Insulation Layer n Protective Layer 4.4 Thermal Insulation Layer In order to avoid cold bridges, inverted flat roof designs require boards with all-around rabbet edges. The boards are joined in one layer, slotted tight with transverse joints (avoid butt joints). In the case of parapet walls or above-grade masonry with bituminous insulation, the Styrodur C boards are to be aligned with the insulation block, which will allow for an installation of the boards that is completely free of cold bridges. Because the insulation boards lie only loosely on top of the roof sealing, they do not affect each other in case of thermal expansions. Practice has shown that it is necessary to install the insulation layer as a single layer. If installed in two layers, a film of water can emerge between the insulation boards, which may thus result in a vapor barrier. Water-vapor diffusion would thereby be prevented, which could lead to concentration of moisture inside the insulation material. In special cases, the Styrodur C boards may be glued pointwise with the sealing, e. g., in bituminous sealing, with blown bitumen B25/85 or cold bitumen adhesive. The thermal insulation layer with Styrodur C boards is accessible for persons and vehicles alike. For transports on the insulated surface, use carts with pneumatic tires. Solvents or solvent-based materials will damage the Styrodur C boards. Styrodur C. If the Styrodur C boards are stored over extended periods of time, they should be covered with light-colored plastic foil to protect them against sunlight. Do not use dark or transparent cover sheets, as those may lead to high temperatures underneath. 4.5 Protective Layer As mentioned above, the thermal insulation layer for an inverted flat roof design always goes on top of the roof sealing. The insulation material is therefore exposed to the elements throughout the year. The polymer chains of the closed-cell rigid foam cannot permanently sustain ultraviolet rays. For this reason, it is necessary to always install a protective layer on top of the insulation. The protective layer fulfills the following functions: Protecting the insulation boards from direct UV rays. Protecting the interconnected roof layers from the effects of wind suction. Protecting the roof from flying sparks and radiating heat (solid roof covering). Protecting the insulation boards from floating. Generally, the protective layer consists of gravel. However, it can also be a useful layer, depending on the use of the roof, such as a green roof, a roof terrace, or a parking deck. The material used for the protective layer thus depends on the application of the roof. Styrodur C boards can be stored outside for several weeks with no additional protection against the elements because neither rain, snow, nor frost can damage 4 Applications Fig. 10: Roof intake. Fig. 11: Inverted roof with gravel. Note: If Styrodur C is installed below roof membranes, sheeting, or protective coating, the boards may tend to deform during the summer when exposed to high temperatures. Therefore, it is vital to install the protective layer immediately according to the Guidelines of flat roof constructions. 12

13 Inverted Gravel Roof 5. Applications 5.1 Inverted Gravel Roof Fig. 12: Structure of inverted roof with gravel. In this case, a layer of gravel (washed, round gravel Ø 16/32) acts as the protective layer of the inverted flat roof. The layer of gravel corresponds to the thickness of the insulation layer. If necessary, the gravel can be covered with a sealer. The sealer, however, must not form a film on the boards. If the insulation boards are thicker than 50 mm, and a supplementary polymer fleece is installed, it might be enough to reduce the gravel layer to 50 mm, even with much thicker insulation boards (Index 5). Index 5: Protecting the boards against floating. A polymer fleece resistant to decay and capable of capillary diffusion is installed between the insulation layer and the gravel. It thereby offers protection for the sealing from damages caused by penetrating small gravel parts. At the same time, the weight of the gravel prevents the Styrodur C boards from shifting or tilting that might be caused by water or wind. Polymer membranes or polythene sheets should not be installed because they act as a vapor barrier, which would cause the insulation layer to soak in the water accumulating underneath. After each rainfall, small amounts of water remain on the roof sealing, which must have the chance to evaporate. It usually does so through the grooves of the boards by diffusing through the insulation material. This explains one of the fundamental rules of inverted flat roof systems: a diffusion-capable layer must always be installed on top of the insulation material. Protection measures against the effects of wind suction must be taken in accordance with DIN : or DIBt approval no. Z (see Index 6). Geographically exposed constructions might need a much higher load than indicated in Index 6. Examples would be constructions built on ridges or hillsides that are exposed to strong winds or constructions in inner cities, surrounded by even higher buildings that can cause extreme strong winds or turbulences. Roofs exposed to regular access (e. g., for chimney or ventilation inspections) should be equipped with walk-on pavement slabs. Thickness of Layer of gravel (in mm) insulation layer in mm without fleece with fleece Index 6: Protecting the roof from the effects of wind suction. Heigt of Fringe in accordance with DIN b/8 Remaining surface eave above min m (b = width of flat roof) railing 0 8 m 1.0 kn/m 2 60 mm 0.5 kn/m 2 50 mm gravel layer gravel layer > 820 m 1.6 kn/m 2 90 mm 0.6 kn/m 2 50 mm gravel layer or slabs (350 x 350 x 60 mm) gravel layer on fine gravel or support > m 2.0 kn/m mm 0.8 kn/m 2 50 mm gravel layer or slabs (500 x 500 x 80 mm) gravel layer on fine gravel or support 13

14 Duo Roofs 5.2 Duo Roofs The duo roof is one option of inverted flat roofs that should be taken into consideration if the requirements concerning the thermal transmission coefficient are especially high and the required thickness cannot be met with one layer of insulation. In this case, one layer of thermal insulation is installed underneath and above the roof sealing. A barrier on top of the reinforced concrete pavement is not necessary. Depending on the climatic conditions, some cases may not even require a vapor barrier. Compared to standard inverted roofs, the duo roof has the advantage of requiring a thinner insulation layer because, as per DIN , a cold bridge addition does not have to be accounted for. Fig. 13: Structure of duo roof. Fig. 14: Installation of boards on duo roof. Fig. 15: Parapet insulation with Styrodur C. Fig. 16: Installation of Styrodur C on top of roof sealing. 14

15 Plus Roofs 5.3 Plus Roofs If the reinforced concrete pavement provides the necessary load-bearing capacity, a reconstructed warm roof may also be converted into a green roof, but it is vital to check whether the roof sealing is strong enough to prevent the formation of roots; if necessary, apply a second layer. Fig. 17: Left: new plus roof; right: old warm-roof design. The plus-roof design is the perfect choice to reconstruct an old, insufficiently insulated warm roof so as to meet today s thermal insulation requirements. In order to reconstruct an existing warm roof with gravel into a plus roof with, the following steps are necessary: Fig. 18: Reconstructed inverted roof in the form of a plus roof. The existing layer of gravel is removed in sections and stored on the roof, respecting the given static requirements. Next, the existing sealing is examined for leakages and repaired, if necessary. The same is done for above-grade masonry, skylights, ventilation plugs, and roof gutters. Connecting points must be 15 cm above the top edge of the gravel for rising parts and at least 10 cm for roof gutters. Fig. 19: Gravel roof. The Styrodur C boards are installed and covered with geotextile and the gravel is placed back on top. Follow the described method in sections until the complete roof is reconstructed. 15

16 Green Roofs 5.4 Green Roofs charge of the sealing and thermal insulation while the roof gardener takes care of the substrate and the greening. Obviously, the extruded foam insulation boards of an inverted-roof design must not be permanently covered with rainwater. Therefore, the following needs to be considered when planning the water storage of an inverted green roof: compliance with the requirements of construction physics and the principles of inverted flat roofs, a diffusion layer must be placed between the water storage level and the thermal insulation boards made of Styropor C compact boards (Fig. 23). Fig. 20: Green roof. As long as a professionally constructed inverted roof is present, i. e., with a layer open for diffusion above the thermal insulation, it is possible to design a green roof with water areas, pathways, and little plazas. The inverted green-roof design holds many advantages compared to the warm roof. The thermal insulation permanently protects the roof sealing with root barrier against thermal strains. Especially during construction, the insulation package protects both the sealing and the root-barrier course from damages caused by mechanical strains. Moreover, once the green roof is in use, the thick thermal insulation protects the roof sealing against rakes or other garden appliances. Fig. 21: Vital cityscape created with green roofs on. During the construction period of a green roof, there is a clear separation between the trades. The roofer is in Temperature profile 10 C Outside temperature + 35 C Substrate Fleece filter Seeping layer Geotextile Root-barrier course Reinforced concrete pavement 10 C 0 C + 10 C + 20 C + 30 C + 40 C + 20 C Indoor temperature Fig. 22: Strain on a green roof. 16

17 Green Roof Due to the egg carton shape of these boards (e. g., Zinco WD 65), the rainwater remains on the surface while the excess water is drained through the cavities to the rear side. Another alternative is the vegetated accessible roof terrace (Fig. 24). Part of this design is a fleece positioned between thermal insulation layer and the drainage course. This layer drains the excess rainwater while the cavities inside the gravel course act as a sealing capable of diffusion for the extruded foam boards. On top of the gravel drainage course, the designs may vary. Part of the roof may be covered with a ponding system made from welded membranes. Other parts may be converted into a terrace with bedding sand and fleece, or fleece and a substrate for greening the roof. Fig. 24: Vegetated accessible roof terrace with pond irrigation system on an inverted-roof design with full gravel drainage. The planner must always take into consideration both the roof s load-bearing capacity for the substrate in wet conditions and the possible weight gain of the plants (Index 7). The thermal insulation boards used for inverted roofs must bear a long-term compressive stress of 130, 180, or 250 kpa, depending on the materials used, which corresponds to load effects of between 13, 18, and 25 metric tons per square meter. Fig. 23: Styropor compact boards for the drainage and retention of water on a green inverted flat roof with. Index 7: Surface load due to vegetation in wet and leafy conditions. Type of vegetation Surface load kg/m 2 kn/m 2 Lawn Small bushes and groves Bushes up to 1.5 m Bushes up to 3 m Tall bushes up to 6 m Small trees up to 10 m Trees up to 15 m

18 Green Roofs Extensive green roofs Extensive green roofs only need little or no maintenance, except possibly one or two inspections a year. Natural processes mostly cover irrigation and fertilization. The plants only need additional irrigation during the growing periods. For the most part, extensive greening consists of draught-tolerant plants that are compatible with extreme conditions and regenerate quickly, e. g., expansive small plants (15 cm height). The substrate should be approx. 616 cm. The substrate of an extensive green roof is drained by the drainage course underneath it. A fleece filter should be positioned between the two layers. Several green roof contractors offer a substrate that both acts as a fertilizer for the plants and drains the roof of any excess rainwater. In many cases, those substrate layers consist of expanded clay or shale. Generally, the planner needs to take into account the condition of the various plants as well as their appearance. Vegetation (sedum, moss, herbage) Substrate (low in nutrients, draining) Geotextile (approx. 14 g/m 2 ) Root-barrier course Reinforced concrete pavement Fig. 25: Profile of an extensive green roof. Intensive greening Intensive greening can be divided into simple and high-maintenance greening. Simple intensive greening requires a medium amount of maintenance. Requirements toward the plants concerning the construction of the layers as well as irrigation and fertilization are moderate (grass, bushes, or groves up to 1.5 m). Fig. 26: Installation of boards under extensive roof greening. Fig. 27: Extensive greening with drought-resistant plants. High-maintenance intensive greening, however, is to be planned thoroughly and needs the constant care of a gardener. It requires irrigation, fertilization, mowing, and weeding. Generally, the substrate is between 10 and 60 cm, depending on the use of the roof. The height of the plants should be between one and three meters. The possibilities of utilization and design of such roofs are practically boundless. 18

19 Green Roofs The Professional Association for Constructional Greening (FBB) provides a list of all membranes and sheets exhibiting such properties. An updated version of the list can be found on In the construction of inverted green roofs, the extruded polystyrene rigid-foam boards must never be installed above the root-barrier course. They would act as a wrong-sided vapor barrier and cause the accumulation of water within the insulation material. Filter and seeping layer = drainage Fig. 28: Intensive green roof. Most suitable are plants used for extensive and lowmaintenance intensive greening, ornamental lawns, high-maintenance bushes between three and six meters of height, as well as small and tall trees. In order to permanently maintain a green roof whether extensive or intensive certain points must be taken into account for each layer. The vegetation on a green roof should be capable of storing great amounts of water in order to survive possible periods of draught. However, excessive water must be disposed of through the seeping layer into the draining pipe or roof outlet. Therefore, the seeping layer becomes part of the drainage layer. Since small parts of the substrate may damage the seeping layer, a fleece filter should be installed between the two for protection. The most common choice is synthetic fleece from polypropylene or polyester fiber with a mass per unit area of approx. 140 g/m 2. Fiberglass fleece is not suitable because the alkalinity of the ground and water will damage it. Root-barrier course and roof sealing On green roofs, the roots of the plants advance as far as the sealing, following the water. To protect the sealing from damages caused by penetrating roots, only sealing membranes resistant to roots should be used. Fig. 29: Profile of intensive green roof. Vegetation (grass, bushes, trees) Substrate Fleece filter Seepage layer (washed gravel 8/16, entangled polymeric filament mats, EPS drainage elements) Geotextile (approx. 140 g/m 2 ) Root-barrier course Reinforced concrete pavement 19

20 Green Roofs The task of the seeping layer in inverted flat roofs The drainage layer absorbs excess water, which cannot be retained by the vegetation, and leads it along the roof pitch into a drainage pipe or roof outlet (Fig. 30). Substrate Fleece filter Seeping layer Geotextile (approx. 140 g/m 2 ) Root-barrier course Reinforced concrete pavement Fig. 30: Layers of an inverted green roof with a drainage layer for surface-water absorption and a drainage pipe, alternatively. However, the seeping layer of an inverted flat roof must not only drain the excess rainwater but also guarantee diffusion capability above the thermal insulation material. The water vapor diffuses through the thermal insulation layer and gets into the seeping layer in order to precipitate there. Under certain climatic conditions, this condensate can benefit the substrate and the plants of a green roof. If the substrate cannot retain any more water, the condensate flows toward the roof outlet or settles on the roof sealing only to enter the diffusion cycle once more. The drainage layer must withstand the strain caused by the weight of the substrate, various other constructions, and utilization, as in the case of an accessible green roof. Yet it should be as light as possible in order to protect the substructure from unnecessary strain. Moreover, it has to be resistant to frost and decay. The following materials are suitable as a seeping layer. Seeping layer made of concrete drainage stones Drainage stones are only suitable for rather thick substrate layers. They are generally not as suitable for roof greening because they may cause constructional damages. The constant fall of water washes the lime out of the concrete stone, which may settle as lime hydrate inside the roof outlets and pipes and cause sintering and even clogging. Seeping layer made of granular materials (e. g., gravel, expanded clay or lava) Especially in the case of extensive greening with very thin substrate, gravel seeping layers are often the only choice to reach the mandatory superimposed load of 100 kg/m 2. However, for intensive greening with very thick substrate layers, seeping layers made of expanded clay or lava are more suitable due to their comparably light weight. Seeping layers made of foam plastics, e. g., EPS draining boards or entangled polymeric filament mats (e. g., from polypropylene) are especially light. In a technical sense, those seeping layers can be considered drainage layers as well. The entangled polymeric filament mat has a tight fleece on both surfaces, which makes it a drainage system in the form of a mat. EPS drainage boards usually need no fleece layer because their foam structure is already tight. Therefore, they already meet the requirements for both seeping and filter layers. When using plastic drainage elements, please note that the constant strain from vegetation as well as utilization may cause reduction or compression of the material. Therefore, when using deformable drainage elements, the thickness of the elements to be assumed after 50 years must be taken into account to ensure lasting water drainage. Example: Under a strain of 10 kn/m 2, one should only calculate 6080% of the original installation height (Fig. 31). Manufacturers usually provide the corresponding figures for prefabricated drainage elements. 100 Thickness (%) Concrete filter stones Grated mats Slotted PS drainage boards EPS drainage boards Entangled polymeric filament mats Strain (kn/m 2 ) Fig. 31: Creep behavior of various drainage elements in the course of 50 years. Thickness against strain. 20

21 Green Roofs Roof drainage and roof outlets The drainage layer must cover the whole surface of the roof up to any adjacent buildings or above-grade masonry. If there are roof outlets with a diameter of 100 mm or more, parts of the area (up to 150 m 2 ) can be defined as a drainage unit. The roof must have a slope of at least 3%. If the roof outlets are too far apart, there is a risk of excess water accumulating in the drainage layer. In such cases, drainage pipes should be installed. In order to guarantee proper installation, all roof outlets should be at least one meter away from above-grade masonry. On an inverted roof, all roof outlets must have at least two drainage levels. Both the water from above the roof sealing and the excess water from the drainage layer must be able to flow into the outlet. The same goes for rainwater falling on frozen soil. The number of necessary roof outlets is determined in the standards DIN EN and DIN Irrespective of the roof size, at least two outlets must be installed. Drainage layers made of gravel lead directly toward the two roof outlets (Figs. 32 and 33). On the substrate, a separation barrier made of gravel, which is laid around the outlet, keeps the plants from overgrowing and preventing inspection of the shaft. In cases of intensive greening with higher substrate layers, it is necessary to install an outlet with an inspection shaft. Substrate Fleece filter Gravel seeping layer Geotextile (approx. 140 g/m 2 ) Root-barrier course Reinforced concrete pavement Roof outlet Fig. 32: Roof outlet of an inverted green roof with a gravel seeping layer. Substrate Fleece filter Gravel EPS seeping layer Root-barrier course Reinforced concrete pavement Roof outlet Fig 33: Roof outlet on an inverted green roof with EPS drainage boards. Such inspection shafts made of concrete or plastic components are easily connected to drainage pipes, making them readily accessible for inspection or cleaning (Fig. 34). Substrate Inspection shaft Fleece filter Expanded clay seeping layer Root-barrier course Reinforced concrete pavement Roof outlet Fig. 34: Roof outlet with inspection shaft on an inverted green roof with an expanded-clay seeping layer. 21

22 Green Roofs Foundation slabs Substrate Fleece filter Seeping layer Geotextile (approx. 140 g/m 2 ) Reinforced concrete pavement Masonry Elastic sealing Fixing profile Fascia gutter Gravel 16/32 Gravel 8/16 Fig. 35: Inverted green roof adjoining above-grade masonry with fascia gutter. If a green roof is bordering on above-grade fascias, gutters should be installed at the base of the building. These gutters provide a straight and quick flow of the rainwater accumulating at the fascias without additionally soaking the green-roof construction. Fascia gutters in front of windows and garden doors can additionally dispose of excess water before it can penetrate through the grooves (Fig. 35). Vegetation Selecting and combining plants for the vegetation of a green roof is a very difficult and complex task, which should be left to a specialist, e. g., a landscape or garden architect or a gardener specialized in green roofs. The intended purpose as well as the type and form of vegetation must be planned ahead just as thoroughly as the aforementioned constructional requirements. Additionally, consideration must be given to long-term functionality of the green roof as well as the cost of its development and maintenance. As soon as the developer and the planner have settled these basic conditions, they must choose the right physical, chemical, and biological properties, as well as the materials and dimensions conducive to the growth of vegetation. The substrate must be rootpermeable and solid, and able to store enough seeping water and incorporate enough air for the vegetation. Protection against wind suction and erosion The vegetation of extensive and intensive roof greening acts as the gravel layer required for all inverted roofs, i. e., it protects all underlying layers from the effects of wind suction. Often, the vegetation alone is not enough to protect the edges and corners from these forces. Therefore, an additional layer of gravel or concrete slabs, or a combination of a superimposed load and a mechanical fixation will be necessary. In order to determine the wind load, consideration must be give to the German standards DIN or DIN V ENV , as well as to the required superimposed load for the protection against the effects of wind suction in accordance with DIBt approval no. Z Additionally, a protective barrier made of gravel along the parapet will provide fire protection and protect the edge of the roof from overgrowing plants. Index 8 indicates the thickness and superimposed loads required for various forms of vegetation. The figures may vary depending on the object. During the installation and growing phase, the effects of wind and rain may cause erosion of the various layers of the green roof, which can be avoided by means of a stable vegetation layer and higher load assumption. In addition, broken stone can improve the stability of fine-textured vegetation. The easiest way to minimize the dangers of erosion is to choose plants and vegetation suitable for green roofing, e. g., those which quickly expand across the surface of the roof. Particularly in areas severely exposed to wind, hydroseeding and precultivated vegetation mats can lower the risk of erosion. 22

23 Green Roofs Index 8: Required depth of layers and distributed loads for various types of vegetation. Type of vegetation Depth of Total depth of Load assumption vegetation layer greening construction in cm in cm With 2 cm With 4 cm kg/m 2 kn/m 2 drainage mat ballast layer* Extensive greening, low maintenance, no additional irrigation Moss/sedum greening Sedum/moss/haulm greening Sedum/grass/haulm greening Grass/haulm greening (dry grass) Simple extensive greening, medium maintenance, periodic irrigation Grass/haulm greening (grass roof, poor grassland) Wild shrub/grove greening Grove/shrub greening Grove greening Complex intensive greening, Depth of Total depth high maintenance, drainage layer of construction regular irrigation in cm in cm Lawn Small shrubs/grove greening Medium shrubs/grove greening Tall shrubs/grove greening Shrub greening Tree greening * For a 23% slope; for more than 3%, the depth can be reduced to 3 cm. Fire protection The ARGEBAU (Conference of Ministers and Senators of the Federal States Responsible for Building, Housing, and Settlement) has passed fire protection requirements as an amendment to already existing building regulations. According to these requirements, intensive greening constitutes hard roofing. Extensive greening is considered sufficiently resistant if the mineral vegetation layer is at least 3 cm, if the type of vegetation constitutes only little fire load, and if the plants are at least 50 cm apart from all roof penetrations and above-grade masonry. There needs to be protective space consisting of either reinforced concrete slabs or 16/32 mm coarse gravel (Fig. 36). Fig. 36: Gravel shoulder along the edges and roof penetrations. 23

24 Roof Terraces Substrate Fleece filter Root-barrier course Reinforced concrete pavement Parapet plate Insulation wedge Flame-retardant insulation layer Masonry Skylight Masonry Window Gravel Substrate Fig. 37: Fire insulation of an inverted roof with extensive greening. In all buildings, including town houses, the building s partition walls, firewalls, or those approved to substitute firewalls must be no more than 40 m apart from each other and at least 30 cm above the substrate (Fig. 37). 5.5 Roof Terraces Should the cover be laid on crushed stones, the insulation boards are to be protected by a protective fleece so as to prevent particles or chippings from slipping between the grooves or underneath the slabs. The geotextile is made either of polypropylene or polyester fiber. Most suitable for inverted flat roofs are stable fleece filters capable of diffusion, with a mass per unit area of approx. 140 g/m 2. Polythene sheets are not diffusion-capable and therefore not suitable. On top of the geotextile is an approx. 3 cm-thick layer of frost-resistant grit or fine gravel (38 mm), above which the pavement is then laid (Figs. 38 and 39). Fig. 38: Roof terrace. The roof sealing and thermal insulation of a roof terrace are installed in the same way as on an inverted gravel or green roof. The top layer can be a solid, walk-on pavement made of washed-out concrete, preconstructed ceramic slabs, paving stones, or a grid construction, laid either on crushed stones or pavement slab supports. This constitues an extra layer capable of diffusion between the thermal insulation and the pavement, which guarantees the diffusion of water vapor through the insulation material. Concrete slabs Crushed stones Geotextile (approx. 140 g/m 2 ) Reinforced concrete pavement Fig. 39: Profile of inverted-roof terrace with concrete slabs bedded in crushed stones. 24

25 Parking Decks An alternative design is the use of plastic pavement slab support that is weatherproof and resistant to decay. The pavement slab support is located at the intersections of the slab grooves. Spacers guarantee a regular pattern of the grooves. Excess water is guided underneath the slabs onto the thermal insulation. Fig. 40: Inverted-roof terrace with. Laying of the concrete slabs onto the bedding. The surface water draining through the open grooves causes a certain self-purification process between the thermal insulation boards and the pavement. Nevertheless, at least once a year, a few of the slabs should be lifted and the spaces between them should be cleared of any accumulated dirt. 5.6 Parking Decks The sealing of a warm roof is especially strained at the grooves of the driving surface. The insulation layer on top protects the sealing of an inverted roof. Fig. 42: Parking deck in the form of a conventional warm roof and an inverted flat roof. The roof sealing of the warm-roof design could be damaged, whereas it lies safely protected in the inverted-roof design. Fig. 41: Parking deck. The roofs of public buildings, warehouses, and big department stores are increasingly used as parking decks. To minimize the heat loss from the heated areas below the parking deck, they are insulated with boards following the principles of invertedroof constructions. Due to their high compressive strength, Styrodur C boards can handle the strain of parking and moving cars if the following constructional guidelines are followed. The construction of the driving surface can be handled in different ways, following the principles of inverted flat roofs. Fig. 42 shows the structure of a conventional parking deck with thermal insulation. In these designs, the roofing near the grooves of the concrete slabs can very easily be damaged due to the dynamic load of the moving wheels. In an inverted-roof construction, the roof sealing is protected from such dynamic loads by the thermal insulation layer. Option 1: Large-size concrete slabs on pavement slab support Reinforced prefabricated concrete slabs (1500 x 2000 x 80 mm) are laid on top of the Styrodur C boards, which are covered by polyester fleece (open to capillary diffusion). However, around their edges, the boards are approx. 100 mm thick, leading to a 20 mm-high void between the concrete slabs and the thermal insulation boards, which enables the atmospheric moisture to diffuse (Fig. 43). In order to keep the concrete slabs from shifting under the traffic load, the edges should be equipped with rubber cushions that transmit the horizontal forces between the slabs. Reinforced concrete slabs Air film Geotextile (approx. 140 g/m 2 ) Reinforced concrete pavement Fig. 43: Parking deck with large-size reinforced concrete slabs on pavement slab support. 25

26 Parking Decks Because the weight of the cars is only transmitted onto the thermal insulation boards via the edges of the concrete slabs (point load), it is necessary to install Styrodur 5000 CS insulation boards with high compressive strength. Since leveling is not possible when installing these large-size boards, it is very important that the reinforced concrete pavement including the sealing does not show any swelling and the thermal insulation boards can be laid on the full surface. Option 2: Small-size concrete slabs on pavement slab support The surface of a parking deck can also be constructed with small-size concrete slabs (600 x 600 x 80 mm) laid on a pavement slab support system in order to guarantee the voids between the top surface of the insulation boards and the driving surface required by construction physics (Figs. 44 and 45). For example, the slab support can be made of special plastic rings or rubber plates. Thanks to the plastic ring or rubber slab support adjusted to the covering, the height of the concrete slabs can be changed during construction as well as during operation. Similar to Option 1, tile spacers or rubber plates around the edges protect the concrete slabs from shifting. The preconstructed concrete slabs (following strict production guidelines) are weatherproof and resistant to road salt. High-quality concrete and system solutions with certified and tested conelike spreading elements guarantee a horizontally braced driving surface, which is weatherproof and can be installed in a very short amount of time (Fig. 46). Concrete slabs Air film Pavement slab support Reinforced concrete pavement Fig. 44: Parking deck with stilted, small-size concrete slabs. Fig. 45: Concrete slabs laid on using pavement slab support. Fig. 46: Parking deck with concrete slabs; inverted-roof design with Styrodur C. 26

27 Parking Decks Option 3: Parking deck with composite paving Except for the polyester fleece, this structure is identical with the aforementioned designs. For the bedding layer of the composite paving, we suggest frost-resistant, grain-selected grit (grain size 2/5 mm). After the compaction process, the bedding layer should be approx. 5 cm deep. The necessary slope of > 2.5% should be predetermined by the reinforced concrete pavement. All further layers are equal in depth, running parallel to the reinforced concrete pavement. Suitable coating would be precast concrete block, clinker, or natural stones. The composite paving should preferably be at least 10 cm deep (Fig. 47). The shape of the stones is very important for the stability of the driving surface; they should be interlocking at the edges in order to avoid possible opening of the grooves parallel to the centerline and pitch axis of the composite (Fig. 48). The grooves between the stones should be filled with paving sand (grain size 0/2 mm). Before final consolidation, the covering should be resanded. In this case, natural crushed stone fines have proven most suitable. Fig. 48: Stone shapes for stable pavement. Only Styrodur 5000 CS is suitable for parking decks with composite paving, since only these insulation boards provide the sufficient compressive strength for the expected traffic loads and the necessary rigidity to avoid excessive sagging. High elastic deformations would cause vertical movements of the surface and thus compromise the stability of the construction as a whole. Composite paving Paving sand Bedding layer Geotextile (approx. 140 g/m 2 ) Reinforced concrete pavement Fig. 47: Parking-deck design with composite paving on top of the bedding layer. Fig. 49: Composite paving with grooves for a parking deck on top of a gymnasium. Fig. 50: Concrete pavement on boards. 27

28 Parking Decks Option 4: Parking deck with cast-in-place concrete The construction of parking decks with cast-in-place concrete on an inverted roof is a very recommendable solution for highly frequented parking lots. This special construction requires thorough planning and execution. The principal structure of a parking deck with cast-inplace concrete is schematically illustrated in Fig. 51. A barrier course and the cast-in-place concrete pavement are installed on top of the load-bearing pavement, the roof sealing, and the thermal insulation with. Cast-in-place concrete Geotextile (approx.140 g/m 2 ) Reinforced concrete pavement Fig. 51: Basic outline of a parking deck with cast-in-place concrete on top of an inverted-roof construction with. In the traditional inverted-roof design, rainwater is leaking into the insulation boards, which is not the case in the construction with cast-in-place concrete. The reduced heat insulation of the inverted roof, caused by the rainwater below the insulation boards, causes economical disadvantages contrary to the construction with cast-in-place concrete, where any additional charge would not be justifiable and therefore is not imposed. In this type of construction, the rainwater is drained completely over the driving surface. Therefore, it is not necessary to place an additional diffusion-capable layer on top of the extruded foam. With no water under the thermal insulation boards, there is hardly any watervapor diffusion. The roof sealing below the insulation layer considerably reduces the transport of the water-vapor diffusion from the inside of the building. That way, no condensate can form within the insulation layer, which is why there is no need for an extra diffusion layer. Certainly, the planner and the developer of such a construction must work very thoroughly so as to ensure that the water is always completely drained through the surface of the cast-in-place concrete pavement. Moreover, there are a few basic guidelines for the construction of such a roof and it is most important that they are respected in order to guarantee the long-term successful operation of the parking deck with cast-inplace concrete. These guidelines do not claim to be exhaustive or universal. It is therefore vital that each case be treated individually by a specialized engineer. Roof construction: The slope of the load-bearing reinforced concrete pavement must be at least 2.5%. The roof sealing must be installed in direct contact with the reinforced concrete pavement so that, in case of a leakage, no rainwater may seep underneath the sealing. This makes it easier to locate the damage below the driving surface. The slope of the roof sealing and cast-in-place concrete pavement must be at least 2.5% and parallel to each other. 28

29 Parking Decks Roof drainage At the lowest point, roof outlets are to be installed (taking into account sagging roof areas). Two levels of outlets must be installed so that, in the case of damage, both the driving surface and the sealing can be drained without the accumulation of backwater. The outlets must be checked and cleaned on a regular basis. The concrete or cement mixture must be composed of high-quality ingredients in order to keep the drainage system from sintering, a consequence of lime hydrate flushing out of the cast-in-place concrete pavement. Cast-in-place concrete pavement Fig. 52: Parking deck with cast-in-place concrete paving. The cast-in-place concrete layer must have a minimum depth of 12 cm. The quality and processing of the concrete must be resistant to long-term frost, decay, and abrasion. The concrete surface must be abrasion-resistant and slip-proof for driving. If necessary, the concrete slabs are to be bolted according to the specifications for the bearing structure. The measuring of the reinforcement must follow the theory of elastic bedding. Formation of grooves Characteristics of thermal insulation in case of water penetrating the parking deck construction If the water-draining top layer made from cast-inplace concrete with joint sealing becomes permeable, letting the water seep under the insulation, a worst-case scenario would imply a calculable moisture absorption into the insulation material. In some areas of the material, moisture contents between 10 and 15% by volume may occur over a period of 20 years. This does not affect the static function of the construction. Damages to the insulation material due to frost are excluded; however, the thermal insulation capacity of the material may decline. The spaces between the grooves should be between 2.5 and 5 m. The planning and construction of long-term elastic sealed grooves (groove backfill) is to be executed by a specialist. The durability of a parking deck constructed with cast-inplace concrete pavement largely depends on the choice, installation, and quality of the joint sealing. 29

30 Parking Decks Research and several publications have shown that the thermal transmission capacity of extruded foam rises by about 2.3% per 1%-by-volume increase in moisture content. With a thermal transmission coefficient of W/(m 2 K) in the dry state, moisture absorption resulting from the failure of the joint sealing would cause the thermal transmission coefficient to rise up to W/ (m 2 K). Presumably, the deteriorated coefficient would be restricted to areas of the parking deck surrounding the drainage system. Therefore, the additional heat loss would remain small in relation to the total energy demand of the building. The thermal transmission coefficient of alternative insulation materials providing the equivalent compressive strength for such designs is between and W/(m 2 K). Fig. 53: Pavement slab made of cast-in-place concrete, sliced for the scientific examination of its long-term properties. The functionality of these designs was demonstrated in practical examples, which are now over 20 years old. Note: The data contained in this publication are based on our current knowledge and experience. In view of the many factors that may affect processing and application of our product, these data do not relieve processors from carrying out their own investigations and tests; neither do these data imply any guarantee of certain properties, nor the suitability of the product for a specific purpose. Any descriptions, drawings, photographs, data, proportions, weights, etc. given herein may be changed without prior notice and do not constitute the agreed contractual quality of the product. It is the responsibility of the recipient of our products to ensure that any proprietary rights and existing laws and legislation are observed. (March 2010) 30

31 6. Technical Data Property Unit 1) Code according to DIN EN C 2800 C 3035 CS 3035 CN 4000 CS 5000 CS Standard Edge profile Surface skin embossed skin skin skin skin Length x width mm 1250 x x x x 615 2) 1265 x x 615 Density kg/m DIN EN 1602 Thermal conductivity Thermal resistance l D [W/(m. K)] R D [m 2. K/W] l D R D l D R D l D R D l D R D l D R D l D R D DIN EN Thickness 20 mm 30 mm 40 mm 50 mm 60 mm 80 mm 100 mm 120 mm 140 mm 160 mm 180 mm Compressive stress or compressive strength at 10% deformation (kpa) 20 mm 30 mm > 30 mm CS(10\Y) DIN EN 826 Compressive creep over 50 years at < 2% deformation (kpa) Rated value of the compressive stress under foundation slabs (kpa) Adhesive strength on concrete Compressive modulus of elasticity (kpa) Dimensional stability: 70 C; 90% r. h. Deformation behavior: load 40 kpa; 70 C 20 mm 30 mm > 30 mm σ perm Short-term E Long-term E50 Linear coefficient of thermal expansion Longitudinal mm/(m. K) Transverse CC(2/1.5/50) f cd kpa TR 200 > 200 CM 10,000 15, ) ,000 5, , ,000 10, ,000 14,000 % DS(TH) 5% 5% 5% 5% 5% 5% % DLT(2)5 5% 5% 5% 5% 5% 5% Reaction to fire 4) Euroclass E E E E E E Long-term water absorption by immersion Long-term water absorption by diffusion Water-vapor transmission (thickness-dependent) % v/v WL(T) % v/v WD(V) MU Freeze-thaw resistance % v/v FT Maximum service temperature C DIN EN 1606 DIBT Z ) N/mm 2 = 1 MPa = 1,000 kpa 2) Thickness 30 and 40 mm: 2510 x 610 mm 3) For multilayer laying: 100 kpa 4) Building material class DIN 4102-B1 DIN EN 1607 DIN EN 826 DIN EN 1604 DIN EN 1605 DIN DIN EN DIN EN DIN EN DIN EN DIN EN DIN EN Technical Data 31

32 Further Information on Product Brochure: Europe s Green Insulation Applications Basement Insulation Load-bearing Applications and Floor Insulation Wall Insulation Roof Insulation Ceiling Insulation KTFS 0803 BE - ENGLISH VERSION - March 2010 Special Themes Reconstruction and Refurbishment Thermal Insulation of Biogas Plants Styrodur 2500 CNS Insulation for Underfloor Heating Systems Technical Data Recommended Applications and Technical Data Technical Data and Assistance Data for Dimensioning Chemical Resistance Styrodur C Film: Europe s Green Insulation Website: Styrodur = reg. trademark of BASF SE BASF SE Performance Polymers Europe Ludwigshafen Germany 32