EPDM ROOFING LEXICON

EPDM manufacturers and specialist wholesalers provide everything needed for the installation of EPDM roofing membranes, such as splice tapes, flashings, bonding adhesives, primers and pre-molded pieces to seal details such as penetrations, roof edge profiles and roof edge terminations, rainwater drainage, emergency overflow systems and much more.

In materials science, aging refers to the change in the properties of a substance over time, after prolonged storage or frequent use. Many influencing factors are involved, such as temperature (change), contact with chemical substances, mechanical stress, weathering and environmental influences or high-energy UV radiation, which can lead to material fatigue and damage. When a roofing membrane becomes brittle or fragile, it can no longer fulfill its protective function, needs to be repaired more often and replaced more quickly.

Flat roof topped with a layer of gravel, which serves as ballast for loosely laid roofing membranes, as well as offering protection against UV radiation. The gravel layer also improves thermal insulation and rainwater drainage. The building statics must be taken into account, as a ballasted roof adds more weight to the roof.

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See LIFE CYCLE ASSESSMENT >
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Structural waterproofing is of essential importance for the protection and value retention of buildings. This includes all waterproofing measures to prevent the damaging effects of water (e.g., from soil moisture, seepage water or water under pressure) on the building structure, especially in areas in contact with the ground, such as basements, underground floors, water reservoirs, areas that can be driven on, etc.In materials science, aging refers to the change in the properties of a substance over time, after prolonged storage or frequent use. Many influencing factors are involved, such as temperature (change), contact with chemical substances, mechanical stress, weathering and environmental influences or high-energy UV radiation, which can lead to material fatigue and damage. When a roofing membrane becomes brittle or fragile, it can no longer fulfill its protective function, needs to be repaired more often and replaced more quickly.

Bitumen is a tarry thermoplastic material. It is extracted industrially from petroleum, but there are also natural deposits. Bitumen is insoluble in water and therefore a long-established waterproofing material. Among others, bitumen is used for flat roof waterproofing. It is also used as a binder in asphalt in road construction.

Materials are considered chemically resistant if they retain their characteristic properties unchanged, even if they are exposed to contact with chemical substances for a longer period of time. EPDM is insensitive to a wide range of chemicals. It is resistant to alcohols, ketones (e.g., acetone), esters, acids and alkalis, but not to greases and mineral oils.

Climate change poses new challenges for roof waterproofing. On the one hand, more sustainable materials and processing methods play an important role. In addition, the stress is intensified by the special weather conditions caused by increasingly extreme weather events (e.g., heavy precipitation, storms, summer heat stress, higher humidity in winter).

See EXTREME WEATHER EVENTS >

In construction, the carbon dioxide balance (also known as greenhouse gas balance) refers to the total amount of climate-damaging emissions caused directly or indirectly by a building product. A Life Cycle Assessment (LCA) of buildings considers the entire life of the building, which increases the importance of using particularly durable building materials such as EPDM membranes.

In addition to the laying of the surface, the detailing of flat roof membranes and flat roof renovations must be carried out with the utmost care and quality. Critical details such as roof edges and corners, connections and terminations, penetrations, movement joints, as well as fixtures such as arcade roof lights and skylights etc. are always sealed with the same material as the roof itself.

In materials engineering, durability refers to the period of time during which a material can be used with full function without showing material fatigue or damage until it has to be replaced. The longest possible durability plays a major role in the construction industry, not only for reasons of economy (e.g., to avoid refurbishment costs), but also in the pursuit of greater sustainability and improved eco-balance of objects.

Sustainability indicator that shows the proportion of land of the Earth's available biocapacity that people consume for their lifestyles. The area needed to supply the raw materials and the energy for them is calculated; the unit of measurement is global hectares (gha). The footprint of a human being should not exceed 1.8 gha. In 2019, the U.S. was at 5 gha (Germany: 3 gha). If the entire world population lived like this, we would need a total of five earths.

Symbol representing all environmental resources (energy, raw materials, water) consumed in the production, use and disposal of a product or service, measured in kilograms. To the real dead weight, each thing thus carries a much heavier ecological weight, e.g., a smartphone phone weighing 80 grams has an ecological weight of 75.3 kilograms. The calculation allows comparison of products in terms of their benefits in relation to the environmental effort involved. The lighter the ecological weight, the more environmentally friendly it is. If you want to build sustainably, you should choose appropriate products.

An elastic material can change its shape when a force is applied to it and return to its original shape as soon as the tension is released. This property is central for roofing membranes for the secure waterproofing of buildings, also to compensate for temperature-related building movements. EPDM roofing membranes can be stretched by up to 300% without tearing or material fatigue. It owes this property to its molecular structure, i.e., it does not require any plasticizers.

The reduction of environmentally harmful emissions of all kinds is an important building block in line with the green building trend towards sustainable construction. For flat roof waterproofing, it is recommended to use materials without plasticizers or other harmful substances that could leak out, as well as employing low-emission installation methods.

An Environmental Product Declaration (EPD) provides all relevant environmental information about building products. It is based on independently verified data on e.g., resource use, emissions, climate effects, etc. It provides an important data basis as a building block for the preparation of life cycle assessments of buildings. This allows the sustainability of different variants of a building and the consequences of different material options to be compared as early as the planning phase.

> See EPDM RUBBER

EPDM roofing membranes are a separate group of materials in the field of flat roof waterproofing. In Europe, EPDM roofing systems have been used for over 50 years and are increasingly popular with builders, architects and installers. Thanks to good experiences with EPDM roofing membranes, this durable material is increasingly replacing traditional roofing materials. The material is covered by the material standard DIN 7864 Elastomeric sheeting for waterproofing: requirements, testing.

EPDM membranes (also known as EPDM foil, EPDM roofing membrane, EPDM roof foil, EPDM foil roof, EPDM seal, EPDM polymer, EPDM elastomer) are used in building construction for waterproofing as a roofing membrane or in the form of prefabricated, homogeneous sheets in one piece. EPDM membrane sheets are bonded with seam tape during installation. Prefabricated EPDM membranes can be easily laid out and can be fully adhered, mechanically attached or ballasted.

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See CHEMICAL RESISTANCE >
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Synthetic rubber made from the monomers ethylene, propylene and diene, developed in the 1960s. Due to the specific properties of EPDM, a wide field of applications in industry and construction quickly opened up. EPDM rubber can be used in many ways: in industry, it is used for profiles in automotive and equipment manufacturing, conveyor belts, hoses, etc. In construction, EPDM membranes are used for waterproofing roofs, facades, water reservoirs and ponds.

Form of flat roof waterproofing in which the roofing membrane is laid without any other protective layer on top (such as gravel, greenery or solar modules). The membrane remains visible and is exposed to UV radiation and weathering. UV-resistant materials, such as EPDM roofing membranes, are particularly suitable for this type of roof. Exposed roofing membranes must be mechanically fastened or adhered to be stable against wind uplift.

Heavy precipitation (hail, rain, snow), storms, flooding, etc., that deviate significantly from the local average are considered extreme weather events. According to studies, such extreme events are increasing worldwide due to climate change. This poses major and new challenges for roof waterproofing. The entire building envelope, from the foundation to the roof, is subject to increasing stresses, which must be considered when waterproofing.

Roof with a low roof pitch of less than 10°. Flat roofs have been known since antiquity. In modern architecture, they have become more popular and are now used in all types of buildings (residential, commercial, industrial) of all sizes. A distinction is made between accessible and not accessible roofs.

See FLAT ROOF SLOPE >

The repair, maintenance or renewal of a flat roof must be carried out if the roof shows damages, if the waterproofing material has aged and can no longer fulfill its function, in the case of energetic renovation (e.g., thermal insulation) or if the roof is to be used for a new purpose (e.g., installation of green or solar roofs).

The angle between the horizontal and the roof surface is called the roof pitch or slope: The pitch is given as an angle in degrees, the slope as a percentage.

Waterproofing of flat roofs to protect against moisture and exposure to the elements. There are various materials that can be used for flat roof waterproofing, such as bitumen, synthetic roofing membranes, liquid plastic roof waterproofing and EPDM rubber, among others.

Internationally used term for holistic sustainable construction, with which the construction industry contributes to the preservation of an intact ecosystem. The guiding principle aims to reduce resource consumption and environmental and health damage over the entire life cycle of a building and its use, and to increase people's quality of life and work. Internationally, there are various certification standards for so-called green buildings.

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Vegetated roofscapes offer immense economic, visual and environmental benefits to the building itself. Furthermore, the entire surrounding area benefits through better climate and quality of life. The green roof trend has been growing for years with society's increasing awareness of climate protection and sustainability and is encouraged by government programs. Green roofs place however special demands on the roofing membrane; they must be particularly resistant and root-proof in the area as well as at penetrations and details.

See EXTREME WEATHER EVENTS >

Chemically inert refers to chemically stable substances that do not react, or react only to a negligible extent, when exposed to substances such as air, water and chemicals. In contact with other materials, inert substances therefore do not cause any harmful effects on the environment or on human health. Therefore, they are not subject to any pollutant requirements for disposal. EPDM rubber behaves inertly throughout the entire process from manufacture to installation to use.

Thermal insulation in a building is intended to reduce the heat transfer through the building envelope. The aim is to protect the interior of the building from heating during summer and from heat loss during winter. This ensures a higher quality of use. It also increases energy efficiency. Thermal insulation measures affect the roof insulation. 

In the construction industry, a Life Cycle Assessment (LCA) is the systematic analysis and holistic evaluation of all direct and indirect environmental impacts of products and services related to the complete building object. The entire service life of the building, including use, demolition and disposal, is taken into account. An important building block as a data basis are the Environmental Product Declarations (EPD) of the building products used. The life cycle assessment procedure is described in DIN EN ISO 14040/14044.

Systematic consideration of the environmental impact of products over their entire life cycle and is now also an important basis for sustainable construction in the building industry. 

In construction, the sum of all costs incurred by a building over its entire life cycle (Life Cycle Costing LCC). It is not only the initial investment (e.g., building materials, building technology, equipment) that is significant, but also the much greater costs incurred during use, e.g., for energy, maintenance, value retention and servicing. The holistic consideration of the overall cost situation up to dismantling and disposal enables the efficient comparison of different material decisions, planning and realization variants.

Lightweight structures and materials have long been a feature of the automotive and aircraft industry, and are becoming increasingly important in the construction industry. The aim is to ensure high functionality and resilience with less weight, thus reducing material and resource consumption, waste and greenhouse gas emissions. It is not only in the construction of industrial halls and warehouses that lightweight construction offers itself as a cost-effective solution with optimal use of space and flexibility in space utilization.  

Under external influences such as mechanical or chemical stress, temperature, weathering, etc., the properties of a material can gradually change over a longer progressive aging process in such a way that it no longer fully fulfills its function or even fails completely. Some waterproofing materials can become brittle, cracked and water-permeable over time. This is not the case with EPDM membranes, which, according to an SKZ study, shows virtually no material fatigue even after more than 50 years of use.

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Monomers are small, particularly reactive molecules that can be combined to form polymers. Monomers are the building blocks for the production of complex plastics and synthetic rubbers such as EPDM rubber.

Substances added to some plastics to make them elastic. Some plasticizers are harmful to the environment and health and, as a consequence, are banned in many applications (e.g. toys, food packaging). Plasticizers can evaporate over time and release harmful substances. Additionally, this jeopardizes the function of roofing membranes, as the plastic membrane loses its elasticity and can crack. Due to the structural elasticity of rubber, the use of plasticizers is not required in EPDM roofing membranes.

Flat roofs are particularly well suited for the installation of photovoltaic systems for energy or heat generation, as they offer large, mostly unshaded areas and allow simple, cost-effective installation and maintenance of the modules. In principle, all commercially available solar systems can be mounted over EPDM flat roof membranes. One advantage is the lightness of EPDM, as the roof already has to bear the weight of the solar panels. It must also be taken into account that the roof has to be accessible for the maintenance of the solar panels.

Polymers are compounds of many smaller molecules, so-called monomers, to very large, long-chain molecules, from which a wide variety of plastics and synthetic rubbers are composed, such as EPDM polymer.

EPDM sheets prefabricated at the factory which are available tailor-made. They are delivered to the job site in one piece, as a "tailor-made suit". This eliminates the need for manual seam joints, facilitating and accelerating the installation. The sheets provide an attractive homogeneous seamless appearance and ensure identical material characteristics with consistent high-quality waterproofing everywhere.

Local building codes include comprehensive requirements for preventive structural fire protection to prevent fires from starting in the first place. On flat roof waterproofing, EPDM has the advantage that it is installed without the need of an open flame. EPDM roofing membranes are therefore particularly useful in timber construction as well as in the renovation or redensification in densely built-up areas.

On sustainable buildings, systems to use rainwater for garden irrigation or toilet flushing are often used to save valuable drinking water. Vegetables can be safely watered with rainwater collected from roof surfaces waterproofed with EPDM membranes. Since there are no plasticizers, herbicides or pesticides in EPDM, no pollutants are emitted into the water.

Redensification is gaining importance in urban development as a sustainable alternative to urban sprawl and sealing of the environment. To this end, areas in existing development are being developed for residential and commercial space, e.g., by adding storeys or docking with existing properties. The use of low-emission, time-saving materials is recommended to optimize the LCA and keep the construction impact on local residents low. Preventive fire protection also requires special attention when building in existing structures.

In chemical-technical terms, resistant materials are materials that are resistant to chemical-physical attacks, such as cold-resistant, UV-resistant, solvent-resistant, etc.

See CHEMICAL RESISTANCE >

High resistance to aging in roof waterproofing is a decisive factor for the value retention, cost-effectiveness and eco-balance of building products. The longer a material is resistant to aging, the longer the rehabilitation intervals and the longer its overall service life. Due to its structure, the resistance to aging of EPDM roofing membranes is particularly high, as they retain their properties for 50 years and longer.

Part of the thermal insulation of the entire building. In the case of flat roofs, an insulating layer is installed to reduce the heat transfer through the building envelope. Only standardized insulation materials may be used. In addition to the usual cost, processing and quality criteria, the main selection criteria are the degree of thermal conductivity, the building material class and, in the case of accessible roofs, the compressive strength.

See ROOT PENETRATION PROTECTION >

Roofing membrane (also roof sealing membrane, roof membrane, roof membrane for flat roof) is a common collective term for elastic materials for waterproofing flat roofs. Roofing membranes are offered in a wide variety of materials and designs, depending on the type and size of building, roof use (e.g., green roof, ballasted roof, solar roof, accessible roof), special requirements (e.g., lightweight construction, timber construction) and the wishes of the building owner or architect for low maintenance, durability and sustainability.

Components that penetrate a flat roofing membrane include chimneys, lightning protection systems, antenna masts, fall protection systems, pipelines, water drains, etc. Any penetration of the waterproofing membrane represents a potential weakening of the flat roof protection. Therefore, the professional installation of the waterproofing system plays a crucial role in these details, including flat roof renovation. Manufacturers of membranes for flat roofs offer a variety of suitable prefabricated and molded parts and accessories for this purpose, which reduce the installation effort and facilitate safe execution.

On green roofs, the growth of roots through the roof membrane must be permanently prevented. For this purpose, an additional protective layer can be laid over the membrane. The preferred solution, however, is the use of a root-resistant waterproofing membrane. EPDM roofing membranes for flat roofs meet this requirement without the use of environmentally harmful pesticides or herbicides.

See FLAT ROOF RENOVATION >

The roof must protect a structure from the effects of weather and precipitation and prevent the penetration of water. While precipitation on pitched roofs is diverted by the roof slope, flat roofs require a waterproof roof seal to the outside. Flat roofs must be airtight to the inside to prevent condensation water from escaping room air.

Collective term for elastic polymers from which rubber is made. Rubber (from Ind. cao = tree and ochu = tear) occurs as natural rubber (e.g., latex, gutta-percha) produced by various plants. Today, synthetic rubbers are used industrially in many ways. Synthetic EPDM rubber (ethylene-propylene-diene monomer) is widely used for roof waterproofing. EPDM is also called EPDM rubber or EPDM membrane.

Common name for EPDM elastomeric membranes for waterproofing flat roofs and building envelopes.

This includes all measures for the protection of buildings or parts of it against water and the effects of the weather. This includes roof waterproofing, facade waterproofing, building waterproofing, the waterproofing of water reservoirs and ponds by means of different materials such as EPDM membranes, bitumen roofing membranes, liquid plastic roofing membranes, plastic roofing membranes, etc.

The secure, tight connection of individual EPDM membrane sheets and detail formations. On the construction site, seams are joined manually using splice tape. In the production of prefabricated EPDM sheets, seams are carried out in the factory.

See DURABILITY >

Plastic roofing membranes can shatter if they are quickly exposed to extreme temperature fluctuations or severe frosts. This creates high stresses that can lead to cracks and damage in the material. Such a risk of shattering does not exist with EPDM, since EPDM rubber is permanently temperature-resistant from -40 to + 120°C.

Roof shape with only one sloping roof surface. It is mainly used on industrial buildings (production halls and warehouses), in the residential sector often for garden sheds or garages and occasionally as a special architectural accent for residential or special buildings such as churches. EPDM roofing membranes are particularly suitable for waterproofing shed roofs. 

The German Plastics Center (Das Kunststoff-Zentrum - SKZ) is an independent service provider for research, testing, certification and further training in plastics technology. SKZ experts monitor products worldwide and advise public clients and companies. The sponsor is the Association for the Promotion of the South German Plastics Center (FSKZ e. V.). The SKZ conducted a study which attests to the EPDM roofing membrane's service life of more than 50 years.

See FLAT ROOF SLOPE >

Solar power or solar thermal systems for generating energy or heat on flat roofs are an important component in sustainable building. Since the roof already has to bear the load of the solar panels, using a lightweight yet robust and resistant waterproofing material such as EPDM roofing membranes is recommended. For regular maintenance of the solar panels, the roof membrane must be accessible. It is also important to have securely sealed details when mounting solar panels.

See PHOTOVOLTAIC ROOF >

Petroleum-based raw materials (monomers) are processed by polymerization and vulcanization to produce an elastomer with rubber-elastic characteristics. Unlike natural rubber, synthetic rubber has saturated carbon compounds and thus a stable skeletal structure that does not allow any undesirable reactions and oxidation processes (plastic of the M group according to DIN ISO 1629). Result: EPDM does not age, or ages extremely slowly and retains its full function over a very long period of time.

Roofing or sealing membranes made of thermoplastics, such as TPO, PVC, TPE, etc.

In hot summers, which are becoming increasingly common even in Western Europe, temperatures of 80°C and more can occur on a flat roof. In some climatic zones of the world, there are also strong short-term temperature fluctuations. The function of the EPDM roofing membrane is ensured even at such extreme temperatures. Thanks to its chemical structure, it is temperature resistant from -45°C to +130°C. Therefore, EPDM membranes can be used all around the world and can be easily installed in any season.

A flat roof offers very good conditions for use as a place for people to stay and maximize the usable area of a building (e.g., roof terrace, sports/playground, gastronomy), as a green area or roof garden, or even as a parking area. In addition to structural and design aspects, this also places special demands on the type, load-bearing capacity and resistance of the materials used for roof waterproofing.

Via solar radiation, UV-A and UV-B rays reach the earth and, consequently, the roof. Extremely high-energy UV radiation can split chemical compounds, so materials can be damaged, become brittle and disintegrate. High UV resistance, as is the case with EPDM roofing membranes, is therefore a particularly important characteristic for roof waterproofing, which is constantly and — due to climate change — increasingly intensively exposed to solar radiation.

The vulcanization method was developed by Charles Goodyear in 1839. During the vulcanization process, rubber is subject to the effects of time, temperature, pressure and chemical reactants (sulfur, peroxides). In simple terms, this produces a highly elastic and resistant rubber. This is also the case in the production of synthetic EPDM rubber. 

See EXTREME WEATHER EVENTS >

An increase in the number of extreme weather events results in more storms. In strong winds, a wind current with a pulling force (Bernoulli effect) acts on the roof of buildings. To prevent waterproofing membranes from lifting off, local rules for protection against wind suction must be complied with and suitable fastening methods must be used (e.g., mechanical fastening, ballast, green roofs, bonding with EPDM adhesive, etc.).