Inspection of Fire Dampers

Due to its very good technical properties asbestos was used in fire dampers until the end of the 1980s.

Apart from the damper blades and - depending on the manufacturer - other construction elements, mainly the compression seal fittings consisted of asbestos-containing foamed material (product name "Litaflex").
 

Asbestos-containing fire dampers are known from the following manufacturers, among other things:
CEAG, HELIOS, KUFLER, NORDLUFT, SCHAKO, STADLER, STRULIK, TROX, WILDEBOER

Typical mounting conditions of fire dampers

 

 

Typical mounting conditions of fire dampers

 

Overview of the most important dates:

• at the latest until 30 September 1984 (depending on the manufacturer), TROX until June 1981:
  asbestos-containing damper blades, compression seal fittings and other construction elements
• until 31 July 1988 (TROX, SCHAKO), until end of 1988 (KUFLER):
  asbestos-containing compression seal fittings ("Litaflex") and sporadically fiber cement
• from mid-August 1988 (individual manufacturers not before January 1989): asbestos-free

 

All these construction elements are "friable asbestos products" in terms of TRGS 519 ("Technische Regeln für Gefahrstoffe: Asbest – Abbruch-, Sanierungs- oder Instandhaltungsarbeiten“). Since the late 1970s, the law requires all owners of existing buildings to obtain an expert assessment with regard to a possible need for remediation for asbestos-containing building materials.

So far this has been performed on the basis of the asbestos guideline ("Richtlinien für die Bewertung und Sanierung schwach gebundener Asbestprodukte in Gebäuden") which, depending on the assessment results, requires immediate renovation or regular reassessment depending on the condition and use of the building.

Old fire damper with flap and seal containing asbestos

 

 

New fire damper with asbestos-free seal

When the asbestos guideline was first introduced in 1989 it required a general classification of asbestos-containing fire dampers (without individual assessment) into urgency of abatement level III ("long-term reassessment necessary", i.e. within a maximum of 5 years) without direct need for remediation. The reason for this was that undamaged damper blades and gaskets hardly releasing any fibers during normal operation could be assumed at that time.
Nowadays, a large number of the old asbestos-containing fire dampers are still in operation, but they show distinct symptoms of aging (especially at the compression seals).

 

Therefore, inspecting fire dampers to assess their need for remediation (immediate remediation in case of severe damage or regular reassessments if construction components show only minor damage or no damage at all) is no longer effective for averting possible health risk for the users.

Meanwhile, it has been shown that asbestos-containing fire dampers can release high amounts of asbestos fibers into the ventilation system when triggered (when the damper blade hits the compression seal), as happens during the required regular functional inspections, for example. This has already been taken into consideration in the current LV 45 Guidelines on the Hazardous Substances Ordinance issued by the Commission for Occupational Health and Safety of the Federal States (LASI) dated October 2018.

Severe damaged seal ("Litaflex)" containing asbestos
with adhesions on the flap

 

 

   

Person-related measurements during maintenance work at fire dampers

Maintenance work on dampers containing asbestos is already notifiable. Moreover, safety level measurements are required in case asbestos fibers may reach rooms connected to the ventilation system through the ventilation system outlets during inspection.

Besides this, the protective measures listed in the Hazardous Substances Ordinance in relation to exposure to asbestos (multi-chamber locks with negative pressurization, etc.) which correspond to the regulations in TRGS 519 for “Demolition and reconstruction work on friable asbestos products” (Section 14) must also be taken into account.

As the current legal requirements considerably increase the overall effort involved in operating and maintaining (functional inspection) fire dampers containing asbestos, remediation is now advisable for fire prevention and also commercial reasons.

 

The current state-of-the-art approach is an individual assessment of the condition of the fire dampers by an asbestos expert and the grading of the fire dampers into damage categories depending on the assumed risk of fiber release. As it is often not possible for organizational and/or financial reasons to replace all fire dampers in a building at the same time, this “prioritization” by the asbestos expert and recommended sequence for the demolition or reconstruction is useful. At the same time, this serves as the basis for an agreement between the building owner, building authorities and fire prevention experts.

During the inspection, the asbestos expert also documents the environment of the fire damper (access, room dimensions, etc.) and analyzes it for the presence of other materials suspected of containing asbestos (fire protection boards, mortar, flange gaskets, etc.). These aspects must also be taken into consideration during a demolition or reconstruction.

Our services to you include:

• Expert assessment of fire dampers with analysis for evidence of asbestos
• Assessment of the current condition and grading into damage categories / priority levels
• Technical investigation in the surrounding area of the fire dampers (collection and analysis of material samples)
• Contaminant register
• Renovation and disposal concepts
• Occupational safety concepts
• Bidding documents
• Project management, dismantling supervision

The General Association of Hazardous Material Remediation (Gesamtverband Schadstoffsanierung, GVSS) has certified us as "Remediation experts for surveying and planning" for the remediation of buildings and plants impacted with contaminants.

Moreover the LGA-IUA is qualified as "Examination Center for Contaminated Building Materials and Construction Waste" to perform external quality controls and take on tasks as head technical expert.

The German Demolition Association (Deutscher Abbruchverband, DA) has officially recognized Dr. Kisskalt as an "expert advisor" for the categories "general demolition", "hazardous building materials" and "waste management".