According to DIN 18531-3, Clause 7.8, an extension is the component for backwater-safe bridging of the thermal insulation. The waterproofing sheet is joined watertight on the extension. According to this standard, with the roof drain, a two-part roof system (warm roof) is made. Two-piece drains are therefore mostly used for thermally insulated flat roofs.

For two-piece drains in flat roofs, the terms base elements, bases, drains, extension are at times used synonymously “on the market”, but they are also interpreted or used in different ways.

In addition to the above passage from DIN 18531, EN 1253-2 notes:

“Two-piece roof drains shall have a tight connection between the drain (outlet) and the add-on element.”

The setup of a two-piece drain with extension with regard to the FLECK products is as follows: either a flat roof drain or a flat roof gully or a flat roof body is installed in the vapour retarder level and is joined airtight with the vapour retarder (bituminous or plastic).

In this condition the installed products operate like a drain and can drain roofs reliably during the construction phase before the flat roof has been completely insulated and sealed. This means that – regardless of the designation – this component installed in the vapour barrier level must first function as a drain.

If the flat roof is then fitted, for example, with insulation and roof waterproofing is laid on top of it (bitumen or plastic or elastomeric roofing sheet), this additional build-up must be supplemented with a so-called extension. The extension bridges the insulation level and in turn performs the function of an “extendable” flat roof drain. The extension generally has a piece of pipe that can be shortened and is inserted in the existing FLECK flat roof drain or FLECK flat roof gully or the FLECK flat roof body. To connect the thus-formed two-piece flat roof drain, vapour and watertight, the two components can either be bonded or they are protected by a FLECK flat roof body with backflow seal.

Summing up: All FLECK flat roof drains, FLECK flat roof renovation drains and FLECK flat roof gullys are basically suitable extensions, which are installed in existing drains, gullies or base elements and thus form an extended two-piece drain in the flat roof in order to bridge the insulation level safely.

In the event of a FLECK flat roof gully that has been installed in the vapour retarder level, note that the pot diameter corresponds to a DN 150 pipe and is therefore a FLECK flat roof drain DN 150 is added to it to increase the height (Important: Do not forget the bonding, as the gully does not have a backflow seal).

The FLECK roof accessories include an extensive range of complementary products for the roof trade. The products are produced for pitched roof, flat roof and solar applications. They include, among other things, completely assembled tile systems for ventilations, penetrations, roof access, snow guard systems, photovoltaic and solar heat systems and suitable accessory parts. The flat roof vents, feedthroughs, gullies and drains, inspection chambers fitted with individual flanges and appropriate complementary accessories, such as the unique ROOFGUARD leaf screen, make it easier to construct safer flat roofs.

The roof ridge (ridge for short) is the term used for the top, generally horizontal, end of a pitched roof. At this point of a pitched roof, for example, the two sloped roof surfaces meet. On tiled roofs the ridge cover mostly consists of half-round ridge tiles made of clay or concrete, which provide rainproof cover for the top ends of both sloped roof areas. On older tiled roofs, the ridge tile was frequently laid in mortar. Modern ridge solutions can be fixed with clips and equipped with special ridge elements. They provide ventilation options for the roofs along the whole ridge, the highest point on the roof. Air can therefore flow from the eaves to the ridge. The ridge is generally horizontal, however, in exceptional cases it can also be sloped and should not be confused with the so-called hip.

Flat roof base elements are used to pass through ventilation ducts, drainage pipes and other penetrations, for example, through ceilings made of concrete. The one-piece FLECK base elements consist of a stable flange and a connecting pipe in diameters DN 50 – DN 500. Flat roof base elements form a precise-fitting base for extensions, roof drains, gullies, vents and ventilators, and goosenecks in the corresponding diameters.

Two variants are available to choose from:

1. Base elements for bonding the attached pipes of vents, drainage or penetrations
2. Base elements with integrated backflow seal, for simplified installation (without bonding!) of the attached vents, drainage and penetrations

Information on the product can be found here.

A flange is commonly used to describe a ring-shaped disc with the help of which pipes are joined together. In general, this ring is permanently attached to the end of a pipe. The two pipes are then joined by bolts, which are inserted through holes in the adjacent flanges, and nuts.

Based on this, FLECK calls the foot or baseplate of its flat-roof products a flange. FLECK products have flanges in diverse sizes and shapes and are used for secure support on level surfaces such as flat roofs. Tapered holes in the flange make it easier to fasten them securely on the surface. A flange enables proper connection of vapour retarders and roofing sheets. The technical information of the sheeting and roof waterproofing material manufacturers must be noted. The flange can have collars already attached by FLECK in the factory and made of the most common roof waterproofing materials (bitumen, plastic and elastomeric roofing sheets).

The hip is formed by the upper connecting line of two adjacent sloping sides of a roof that meet with a downward slope. They are classically found on hip(ped) roofs, mansard roofs, pyramid hip roofs, jerkinhead roofs and dormers. At a hip, the cover at the ridge is mostly made of half-round clay or concrete ridge tiles, which provide rainproof cover for the top ends of both sloped roof areas. These can be set in mortar or fixed with clips. The counterpart of a hip is the bottom sloped connecting line between two sloped roof areas, which is called the valley.

The valley forms the counterpart to a hip. It is the bottom inclined connecting line between two pitched roof areas. Water running off the meeting roof areas is guided along this connecting line in the direction of the eaves or roof gutter via appropriately adapted valley flashing.

FLECK inspection chambers are used on thermally insulated flat roofs. They enable fast inspection of the insulation layer, without having to open the flat roof waterproofing. Penetrated water or increased moisture content are quickly identified in an inspection chamber. Inspection chambers are offered as a two-piece solution (slotted base element + inspection chamber), as well as a one-piece solution e.g. for subsequent installation.

To minimise thermal bridges, FLECK uses a stable EPS insulation core in the thermal conductivity group WLG 040, which can be removed for inspection, in the inspection chambers for insulated flat roofs.

Note: In Austria, inspection chambers as defined in ÖNORM B 3691 are specified for roofs in use category K3.

In general technical usage, a collar is a jacket surround, for example, for protection, stabilisation or separation of an item. As a pipe coupling (“collar seal”), they can also be used for tight connection between two systems.

Based on this, FLECK collars are generally made of bituminous membrane or plastic and elastomeric roofing sheets. These are used by FLECK for flat roof products with a flange. The collars are permanently joined with the flanges in the factory and make it easier for the roofer to make the proper joint on the respective roofing sheets present on site.

Due to the large number of roof waterproofing materials offered on the market, FLECK provides a wide choice of appropriate collars. This especially applies to the plastic and elastomeric roofing sheets based on the wide range of materials available on the market. Common PVC, PIB, ECB, EVA, EPDM and FPO-based plastic and elastomeric roofing sheets available for waterproofing are produced by calendering or extrusion. They involve the following materials:

• ECB (ethylene polymer bitumen)
• EPDM (ethylene propylene diene terpolymer)
• EVA/EVAC (ethylene vinyl acetate terpolymer/copolymer)
• FPO (flexible PE or PP-based polyolefin)
• PIB (polyisobutylene)
• PVC-P (Polyvinyl chloride, bitumen-compatible bv or non-bitumen-compatible bn)
• TPE (thermoplastic elastomers)

Information on the possible products and flange and collar types can be found here.

Verge is the name used to describe the edges of the roof on the gable side. They form the side end of a roof along the gable. This is where the roof truss, the roof covering and the gable meet. The verge area is considered to be very sensitive, as if the work is not carried out properly, it can allow the ingress of moisture and unwanted airflows. To prevent this, measures must be taken at the verge, which meet the thermal insulation, air tightness, windtightness, rain protection and wind suction protection requirements.

The roof eaves, or eaves for short, is the name used to describe the bottom “drip profile” on the sloped roof of a building. The collected rain water flows over the eaves. A gutter is frequently attached to the end of the eaves, which catches the water and safely discharges it. The roof area located between the external wall of the building and the eaves is also called the roof overhang. The eaves are the bottom boundary of the roof. The upper boundary is called the roof ridge and the side boundaries, the verge. Hip and valley, represent further limiting lines in the roof area.

WLG describes the thermal conductivity group of thermal insulation materials. The thermal conductivity groups are graduated in increments of 0.005 W/(mK)*, i.e. WLG 035, WLG 040, WLG 045 etc. The smaller the WLG value is, the better the thermal insulation property.

The assignment of a thermal insulation material to a WLG is always determined from the first three places after the decimal of the thermal conductivity “λ”. The thermal conductivity “λ” is generally given in W/(mK). Thermal insulation materials with a λ –value of 0.036-0.040 W/(mK) are then assigned to the WLG 040 class.

To minimise thermal bridges, FLECK uses a stable EPS insulation core in WLG 040, which can be removed for inspection, in the inspection chambers for insulated flat roofs.

*W = Watt, m = metre, K = Kelvin

Sheets for waterproofing unused and used areas must be suitable for the intended use and must be matched to each other and the waterproofing underlay. The materials suitable for the waterproofing of roofs in the respective individual case and the appropriate layer build-up of insulation and waterproofing must be defined when designing the roof. Roofing sheets can be roughly differentiated into the two following groups:

• Plastic and elastomeric roofing and waterproofing sheets (membranes)
• Bitumen sheets

Based on a wide range of materials and different properties, plastic and elastomeric roofing and waterproofing sheets offer diverse possible uses. Produced by calendering or extrusion, common plastic and elastomeric sheets available for waterproofing are based on the following materials:

This waterproofing therefore offers a large variety of materials and therefore covers a wide range of uses. Laid loosely, mechanically fixed or completely bonded, they are used in new build and for repair. The manufacturers’ ranges include sheets from 1.2 mm to over 2.5 mm thick. Apart from many other uses, plastic sheets are also suitable for safe and environmentally friendly waterproofing of green roofs.

ECB is the material designation for a black-coloured mixture based on high-quality polyethylene copolymers with varying fractions of special and different amorphous bitumen qualities. Pure bitumen of one type is homogeneously embedded in the polymer matrix and can therefore be processed as a free-flowing granulate (pellets) in conventional plastic processing plants. In ECB, the positive properties of polyolefins are united with bitumen. Due to its good viscosity, ECB is characterised by high biaxial resistance to strain and flexibility, even at low temperatures. Special stabilisation lends ECB excellent resistant to heat ageing and UV radiation. ECB is not only largely weather and ageing resistant but is also thermostable.

EPDM is one of the synthetic rubbers with a saturated main chain, they have double bonds in the side chains and can therefore be vulcanised with sulphur. The rubber-elastic material EPDM is used in diverse ways by industry, e.g. for profiles in automotive and apparatus manufacture, for conveyor belts, hoses for washing machines and dishwashers, seals for water fittings, for cable sheathing, etc. In buildings, EPDM waterproofing sheets are used to waterproof roofs and façades or as pond liners for waterproofing membrane ponds (swimming ponds and water basins). The material is widely used wherever robust waterproofing materials that are resistant to UV, ozone, acid and mechanical exposure are needed. In 1968, the first flat roof in Europe was waterproofed with EPDM.

EVAC, previously also EVA, are copolymers made of ethylene and vinyl acetate. They are available as pellets, aqueous dispersion, powder, as well as film material. The plastic has high thermal and good ageing resistance. However, the properties and possible uses can be varied greatly with the proportion of copolymerised vinyl acetate. Vinyl acetate fractions up to 7 % are almost exclusively used to improve the properties of films (in particular, increasing their elongation at break). Around half the EVAC produced is manufactured with less than 7 % vinyl acetate. EVAC, with a vinyl acetate fraction of 7 to 18 %, is often also used an exclusive material for special applications. Examples are cold-resistant, pull-out pourers (spouts) of canisters, sheeting for agriculture and gardening, shrink-wrap films (office supplies, solar modules), shower curtains, floorings, roofing sheets and electric cables. In photovoltaics, solar cells are embedded in EVAC. Here the EVAC used in films is melted at temperatures around approx. 150 °C, becomes glass-clear and cross-links three-dimensionally. After cooling, a permanent compound exists, which protects the cells from environmental influences.

Roofing sheets made from thermoplastic polyolefin (TPO) belong to the group of plastic waterproofing systems and consist of alloys of different individual plastics such as polyethylene, polypropylene and polybutylene as well as integrated reinforcement. Various associations and manufacturers also call them flexible polyolifins (FPO), because they are significantly less stiff than, e.g. polyethylene. They are characterised by their good chemical resistance and electrical insulation properties. FPO (PE) are used to produce, among other things, sheeting, films, blown films (bubble wrap), shrink-wrap films, heat-shrink tubing, coatings and packaging. FPO (PP) is used, among other things, as packaging in the medical and in the food sector, for fibres and pipes.

PIB was first produced in 1931 by the Badischen Anilin- und Sodafabrik (BASF SE) in Ludwigshafen-Oppau and was marketed under the trade name Oppanol. PIB can be used in solutions and dispersions for coating. In addition, similar to natural rubber, it can also be processed in rolling mills, in kneading machines, presses, by calendering and extruding. The processing temperature lies between 150 °C and 240 °C. Other applications are sealing compounds, wax admixtures for lining and coating, plaster adhesive and spray plasters, fly trap adhesive on yellow stickers, raw mixture for producing chewing gum, roof waterproofing sheets (membranes), mixtures with polyolefins for improving workability and plasticising explosives such as PETN or hexogen. Polyisobutylene is also used as an additive in other plastics, e.g. in butyl rubber mixtures and as lubricant additive.

Polyvinyl chloride is a thermoplastic polymer, which is produced from the monomer vinyl chloride by chain polymerisation. After polyethylene and polypropylene, PVC is the third most important polymer for plastics. The PVC plastics are divided into hard (rigid) and soft PVC. Rigid PVC is used, for example, to produce window profiles, pipes and records. Soft PVC contains additives which lead to the elastic behaviour of the material. For example, it is used for cable sheathing and floorings. PVC can be easily coloured and absorbs hardly any water. It is resistant to several acids and alkalis and is conditionally resistant to ethanol, oil and benzine. The advantage of PVC is its durability. Sunlight does not cause it to decompose, the mechanical properties are not impaired. Water (including salty seawater) and air can hardly damage or destroy PVC or not at all. PVC is therefore mainly used for long-life products. The products can be produced in all kinds of different colours and decorative finishes (decors). PVC sheeting has different applications, e.g. for the water cores of water beds, as synthetic leather or for film sheets/pockets in stamp albums, as pond liners and roofing sheets in the construction sector and for floorings.

Thermoplastic elastomers are plastics that behave comparably with classic elastomers at room temperature, however, can be deformed plastically when heat is added and therefore display thermoplastic behaviour. Thermoplastic elastomers are materials in which elastic polymer chains are integrated in thermoplastic material. They can be processed in a purely physical process in combination with high shear forces, the action of heat and subsequent cooling. Although chemical cross-linking by time-consuming vulcanisation at high heat, as with elastomers, is not necessary, the parts made have rubber-elastic properties due to their special molecular structure. Renewed heat and shear force action leads to the melting and deformation of the material. At the same time, however, this means that the TPEs are far less able to withstand thermal and dynamic exposure than standard elastomers. The TPEs are therefore an addition that combine the advantages of thermoplastics with the material properties of elastomers. A large advantage of these elastic plastics is the possibility of welding them in order to generate watertight connections.

Bitumen sheets are sheets with carriers and bitumen overlays on both sides. They are usually differentiated into:

Bituminous membrane

• PYE elastomeric bitumen (bitumen modified by the addition of thermoplastic rubbers)
• PYP plastomeric bitumen (bitumen modified by the addition of polyolefin or polyolefin copolymer compound)
• PYE/PYP combination of elastomeric and plastomeric bitumen

Self-adhesive sheets

• KSP self-adhesive reinforced polymeric bitumen sheet
• KSK self-adhesive bitumen waterproofing membrane with HDPE carrier film

PYE elastomeric bitumen (bitumen modified by the addition of thermoplastic rubbers)

Elastomeric bitumen sheets are made from straight-run bitumen (primary bitumen) which is modified with SBS (styrene butadiene styrene) (elastomers). With increasing SBS fraction, the bitumen acquires a rubber-like behaviour, whereby the rubber added can be up to 20%. However, as a higher rubber fraction makes laying and melting the sheets more difficult, most bituminous membranes are made with particularly meltable overlays on the underside of the sheet. The advantages of this type of sheet are its low temperature sensitivity, good thermal stability and very good flexibility at low temperature, the distinct elastic behaviour as well as a long life with high weather and ageing resistance.

PYP plastomeric bitumen (bitumen modified by the addition of polyolefin or polyolefin copolymer compound)

Plastomeric bitumen sheets are made from straight-run bitumen (primary bitumen) which is modified with APP (atactic polypropylene) (thermoplastics). Plastomeric bitumen membranes come from the Mediterranean, where they have been used for decades, particularly due to their high thermal stability: They endure decades of exposure to sunshine without visible change and without loss of their sealing function. The advantages of this type of sheet are its extraordinary thermal stability and good flexibility at low temperature, its plastic behaviour which simultaneously lends the sheet high 2-dimensional stability, a long life with high weather and ageing resistance as well as very easy fusibility. Plastomeric bitumen sheets are generally produced as membranes and are laid using torch-on methods. The plastic fraction of the highest-quality membranes is up to 40% of the bitumen fraction; plastomeric bitumen membranes with small plastic fraction tend to be more like elastomeric bitumen membranes.

PYE/PYP combination of elastomeric and plastomeric bitumen

PYE/PYP combinations achieve improved bending behaviour at low temperatures as well as increased flexibility at low temperature – in combination with polyester felt and combination carriers both elastomeric bitumen and plastomeric bitumen sheets acquire excellent mechanical properties (tensile behaviour, extensibility and resistance to perforation).

KSP self-adhesive reinforced polymeric bitumen sheet

Self-adhesive sheets are polymer bitumen sheets to which a self-adhesive coating is applied on the underside in the factory; after pulling off a release film or release paper, the self-adhesive side can be laid on a self-adhesive-compatible substrate by applying pressure (cold application without torching). The underside overlay is given a self-adhesive finish in the factory. This means that the sheet can be bonded without applying strong heat. Thermal activation, especially in cool outdoor temperatures, is nonetheless recommended by many manufacturers.

KSK self-adhesive bitumen waterproofing membrane with HDPE carrier film

KSK bitumen sheets are a means of waterproofing structures (English tanking, German “black tank”). They consist of plastic-modified bitumen, which is applied on a tear-proof HDPE carrier film. They are suitable for the load cases of soil moisture and non-accumulating seepage water load cases. Self-adhesive sheets (KSK sheets) bridge cracks in the masonry and are resistant to cold and heat. The sheets can be loaded immediately after bonding. More expensive in material costs than bituminous membrane, the advantage of the self-adhesive bitumen waterproofing sheets is their shorter application time. The self-adhesive membrane is rolled out over the whole surface, overlapping and crease-free, whereby the protective layer is pulled off. The sheets may also be laid at slightly below-zero temperatures.

A flat roof is usually the term used to describe a roof with a roof pitch of less than 10 degrees. With the “New modernity” and the increasing popularity of linear design after Bauhaus, the flat roof became an increasingly important roof shape. Due to the low to non-existent roof pitch, flat roofs must be built with watertight roof waterproofing to protect them against standing and penetrating water. Adapted. prefabricated accessory parts are an advantage for safe penetration of the roof waterproofing.

The roof shape found most widely in Europe is the saddleback roof, more commonly called the gable roof in English, which consists of two opposite pitched roofed areas. Also called a gable roof or ridged roof. Gable roofs can have different forms and are subject to a simple design principle. In its basic form, the saddleback roof (more commonly called the gable roof) is a roof shape tried and tested for hundreds of years. And yet the gable roof changes repeatedly because architects like to leave behind their mark or thumbprint in the shape, colour and choice of material. Examples can be found at www.DACHKULT.de.

Pitched roof is the name given to roofs with a pitch of more than 20° degrees. The pitched roof is one of the most popular roof shapes in Germany. The top end of the pitched roof is called the ridge – the opposite of which is formed by the eaves, because they represent the bottom end of the roof. Pitched roofs need adapted systems for ventilation, water routing and discharge, for safeguarding them against snow loads, for access and for the installation of penetrations or additional roof structures, such as solar systems. The FLECK pitched roof-accessories now include several thousand efficient articles.