Vandinstallationer: Eksempelsamling til Bygningsreglementets afsnit 21 og 24 – Danish Water Installation Guide
The Vandinstallationer: Eksempelsamling til Bygningsreglementets afsnit 21 og 24, also identified as Rørcenter-anvisning 027, is a technical reference document issued by Rørcentret, Teknologisk Institut (Danish Technological Institute) in December 2018. It serves as a collection of examples and practical solutions to satisfy the functional requirements established in the Danish Building Regulations 2018 (BR18), specifically focusing on Section 21 (Water) and Section 24 (Materials and Products). The document is part of a larger legal framework governing building construction in Denmark, providing detailed technical interpretations where existing standards like DS 439:2009 may no longer provide sufficient guidance due to technical advancements.
The scope of this collection encompasses all water installations connected to public or private water supply systems within the property boundary (grundgrænsen). It covers new installations, modifications, and additions to existing systems, including the pipework for rainwater systems supplying toilets and laundry machines. The content is organized into specific regulatory domains, including health considerations regarding bacterial growth such as Legionella, protection against frost, leakage testing procedures for metal and plastic piping, and requirements for durability, corrosion resistance, and exchangeability of components. It defines critical technical parameters such as burial depths, pressure test thresholds, and temperature limits for hot and cold water systems.
This document provides structural engineers, plumbing contractors, and building owners with concrete examples and illustrations to ensure compliance with the performance-based requirements of BR18. It details the necessary procedures for operation and maintenance, providing a technical baseline for the design and execution of water-bearing systems in Danish construction projects.
Scope and Validity
The provisions apply to water installations within the property boundary as defined in Figure 1.1. This includes installations connected to general water supplies (public or private) and smaller non-general systems. The regulations cover:
- New installations: All newly constructed water systems.
- Modifications: Changes or additions to existing installations.
- Rainwater systems: Piping systems supplying WC flushing and washing machines from tanks.
- Repairs: Maintenance of pipes and replacement of sanitary items, which may follow the rules in effect at the time of the original installation.
Health and Frost Protection
Water installations must be designed to minimize the risk of bacterial growth, particularly Legionella. Selection of materials like natural rubber and certain synthetic rubbers is discouraged as they may contribute to bacterial proliferation. Protection against frost is required through specific placement and insulation measures:
- Burial depth: Water pipes in soil must be laid at a depth of at least 1.2 meters to the top of the pipe.
- Internal placement: Pipes must be located on the warm side of insulation in external walls, crawl spaces, or attics.
- Basement distances: Pipes entering buildings must maintain a distance of at least 1.0 meter from light wells or basement stairs.
- Isolation: Where pipes are exposed to temporary frost, insulation thickness must be calculated based on DS/ISO 12241.
Leakage and Pressure Testing
Before being put into service, all new or modified installations must undergo a leakage test. The installation must be found leak-tight at the maximum occurring pressure in the supply area, but not less than 600 kPa at the lowest point of the installation. Specific procedures apply based on material:
- Metal systems: Tested for at least 2 hours after the temperature in the system has stabilized.
- Plastic systems: Tested for 30 minutes at control pressure. The pressure is then reduced to half and maintained for at least 90 minutes.
- Air pressure testing: May be performed at a maximum of 50 kPa in special cases, following Arbejdstilsynet (Danish Working Environment Authority) regulations.
Durability and Exchangeability
Installations must have a technical service life of at least 50 years. Non-exchangeable parts must be of such quality that they last the lifetime of the building component they are embedded in. Exchangeable systems are categorized by their accessibility:
- In-ground pipes: Accessible for repair by excavation.
- Building pipes: Accessible by removing cover plates or panels intended to hide the installation.
- Embedded systems: Pipes like PEX or PE-RT in hot water systems must be exchangeable, often using pipe-in-pipe (rør-i-rør) configurations.
Water Quality and Backflow Prevention
Protection of water quality involves securing the internal installation against backflow from the public supply according to DS/EN 1717. Key requirements include:
- Backflow protection: Use of controllable check valves or internal backflow preventers.
- Treated water marking: Systems carrying non-potable water (e.g., rainwater for WCs) must be marked with the text Ikke Drikkevand (Not Drinking Water) and specific colors per DS 134:1960.
- Cold water temperature: Installations must be insulated to prevent cold water temperatures from exceeding 24°C over an 8-hour period to prevent bacterial risk.
Frequently Asked Questions
What is the minimum burial depth for water pipes in soil?
Water pipes in soil must be laid at a minimum depth of 1.2 meters measured from the ground surface to the top of the pipe to prevent frost damage.
What is the minimum pressure for a leakage test?
The installation must be tested at the highest occurring supply pressure, but it must be at least 600 kPa measured at the lowest point of the system.
What is the maximum allowed length for connecting hoses?
Flexible connecting hoses (tilslutningsslanger) for items like toilets or washing machines must not exceed a length of 2 meters.
At what temperature does the risk of scalding occur in hot water systems?
The document identifies the maximum temperature for scalding risk as 65°C, while normal hot water temperatures should not exceed 95°C.
What are the rules for marking non-potable water installations?
Installations for treated or non-potable water must be marked Ikke Drikkevand and colored according to DS 134:1960 to prevent accidental ingestion.
What is the required technical service life for water installation materials?
Materials and components used in water installations must have a technical service life of at least 50 years.
How should stainless steel pipes be used regarding chloride content?
Stainless steel can generally be used where chloride levels are below 150 mg/l, or up to 250 mg/l if mechanical physical properties are documented according to BR18 §418.
What is required for the maintenance of backflow preventers?
Backflow preventers (tilbagestrømningssikringer) must be maintained according to DS/EN 806-5 to ensure the protection function is upheld.
