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Cast iron pipes are fire protection pipes

A drainage pipe installation made up of cast iron drainage pipes and fittings is uncritical in case of a fire and therefore does not require any complex penetration seal. In many cases it is sufficient to close down the gap around the pipe with a non-combusible material - with mortar if acoustic protection should be unimportant, or otherwise with mineral wool. In Germany, the MLAR regulation contains all details on this kind of solution.

The German MLAR regulation allows for these simple solutions even without any test certificates or approvals due to positive experiences that have been made over decades in Germany.


The alternative are penetration seals with official approvals that are offered by various manufacturers of penetration seals. They may have national approvals such as a German abP or abZ, or an European approval such as an ETA (European technical assessment).



The trouble of mixed installations - special approvals required in Germany

For building drainage in Germany and some other European countries, plumbers sometimes apply so-called mixed installations: cast iron down pipes, and plastic horizontal connecting pipes.


Although there are no discernible technical advantages to this material combination, there is a strong preference for this kind of installation particularly in blocks of flats and similar buildings in Germany.


However, German authorities have recognized that this combination of combustible and non-combustible materials in one drainage pipe installation shows particular risks in case of a fire, with the plastic pipes being the weakest "chain link". When installed with the fire penetration seals that are approved for cast iron pipe installations, the insufficient heat resistance of the plastic pipes may cause a fire flashover.


Therefore, since 2013, specially approved penetration seal solutions need to be installed on mixed installations in Germany.


On possible and approved solution for mixed installation in German is the Düker BSV 90. For more details on other solutions approved in Germany, please consult the German version of this web page and follow the link "Mischinstallation".





Reaction to fire - Fire Resistance

The term "reaction to fire" describes how much heat, smoke etc. a construction product contributes to a fire in a room.

The term "fire resistance" indicates how well and how long a building component can hold back the fire and prevent it from penetrating from one room to another.

Note: In general, resistance to fire is not a characteristic of a pipe system. It is a characteristic of a pipe penetration, i.e. a certain way of installing a pipe through a wall or a ceiling, possibly with a special penetration seal.




SML Specifier's Manual
(pdf, 5.118 KB)

With up-to-date information on fire protection with Düker SML drainage pipe systems!



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