Compact knowledge - Fire insulation in construction law

• The fire behaviour of materials, e.g. for pipelines (drains), pipe sleeves, thermal insulation and pipe jackets, is defined by categorisation in set material classes (A1/A2/B1/B2) based on tests carried out according to DIN 4102-1.
• Highly flammable materials must not be used for the field of house technology.
• The basic standard for fire insulation DIN 4102 comprises 18 parts and describes the entire range of fire behaviour of materials and components, and how they are tested. It regulates, for instance, the execution principles of sealing measures, roofing, pipelines and pipe sleeves and the fire behaviour of materials. Given that a component (wall, floor or ceiling construction) comprises multiple individual materials, it is imperative that the individual materials are broken down into non-combustible and combustible. Certification must be provided for the respective categorisation and classification, e.g.:
  
  • Fire trials and testing
  • Compilation of a test report
  • Issue of a General Building Supervisory Authority Test Certificate (aBP), a General Building Approval (abZ) or a General Design Certificate (aBG)
  • By classification in DIN 4102 – Part 4
    

After completion of a fire trial by an authorised testing institute (e.g. MPA-NRW etc.), the material must be assigned to the respective material class and its usability verifiably documented by an abP, abZ or aBG.

When it comes to the fire resistance duration the minimum duration is determined for which the component performs its function when exposed to fire according to DIN 4102-2.

Physical structures and their systems and equipment, in particular when taking into account:

• the flammability of the materials,
• the fire resistance duration of the components, expressed in fire resistance classes,
• the leak tightness of the seals on openings,
• the arrangement of escape routes - must have properties which prevent the outbreak of fire and the spread of fire and smoke. Materials which are highly flammable after processing or installation must not be used for the erection or modification of physical structures and other systems and facilities.

• The Conduit Systems Directive is an essential guideline for the planning and installation of conduits and drains for preventive fire insulation. It has been introduced as construction legislation in almost all federal states. It is thus the implementation ordinance for the federal states. The LAR describes the requirements of conduits, including fastenings and insulating materials, in conjunction with installation in emergency escape routes.
• The LAR aims to improve preventive fire insulation in conduit systems and help all involved in the construction with planning and implementation in order to erect the building to an appropriate and compatible safety standard. It is applied for all building types which are regulated in the Regional Building Codes LBO.
• The LAR defines the execution principles for the penetration of a vertical pipe or a floor/roof drain through a fire-resistant wall/ceiling. In this case, wall and/or ceiling feedthroughs must be in R 30/60/90/120 quality.
• The requirements of the LAR must be met for both non-combustible and combustible drainage pipes.

In principle, fire testing based on DIN 4101-1, carried out by an accredited and state-approved material testing centre / a material testing department, is mandatory for classified bushings in R 30 to R 120 quality. Certification of suitability is provided:

• in the form of a General Building Approval (abZ) or a General Design Certificate (aBG) if foaming materials are used to generate the sealing effect in case of fire, or
• in the form of a General Building Supervisory Authority Test Certificate (abP) if the suitability for fire insulation is achieved by the special installation position.
  The fire testing is used to certify the maximum permitted surface temperature increase on the side facing the fire. This limitation prevents the spread of secondary fires in case of an outbreak of fire.
  

On the basis of approvals and test certificates, the planner does not need to define additional constructional measures when using classified bushings for fire resistance classes from R 30 to R 120. This guarantees absolute planning certainty, in particular when it comes to the interfaces of the bushing to the building structure.

Wastewater, rain drainage, floor drains and roof drains
The Conference of Ministers of Construction (ARGEBAU) published the model directive on fire insulation requirements for pipe systems (Model Conduit Systems Directive (MLAR)), issue date 5 April 2016. The MLAR explains how to achieve the safety objectives specified by the Regional Building Code.

Floor drains are construction products which are regulated by European standards and therefore require no further approval for their function. As soon as floor drains contain mechanisms for preventive fire insulation, these floor drains require a General Building Approval (abZ) or a General Design Certificate (aBG), depending on design. When it comes to floor drains after the "relaxations" of the MLAR, adherence to all framework conditions is very difficult and complex. Installation inspection and acceptance is simpler for classified R 30 to R 120 floor drains.