Closures and closure systems for inspection opening are used to seal revision openings in fire-resistant service ducts or suspended ceilings inside a building or structural work. They prevent fire or smoke from spreading via the revision opening from the inside to the outside of the service duct or from the top area concealed by the suspended ceiling to the area below.

Closures or closure systems for inspection openings consist mainly of a frame and the leaf or leaves.

Closures and closure systems for revision openings are

• factory-made,
• need to consist of non-combustible materials and
• need to close tightly all around;
• they may only be opened from the outside (i.e. from the room) with a special tool or key or similar.

By definition, closures for inspection openings have one or two leaves.

Closure systems for inspection openings, on the other hand, have

• at least three, but no more than five leaves or
• at least two and no more than five leaves arranged one after the other in a double-row.

Regulatory framework

DIBt grants national technical approvals (abZ)/general construction technique permits (aBG) for closures and closure systems for revision openings.

Required verifications:

• resistance to fire in accordance with DIN 4102-2 or DIN EN 1364-1
• for closure systems for revision openings, additional verification of stability and serviceability in accordance with DIN 4102-3.

Please contact DIBt before carrying out verifications for extended applications (EXAP) which are not already covered by the verifications named above.

Closure systems for revision openings may only be executed and installed by the applicant's trained personnel or specialised companies that have sufficient experience in the area and trained personnel.

External surveillance has to be performed by a recognised body (PÜZ-Stelle). You will find the directory of recognised bodies (PÜZ-Verzeichnis) linked in the sidebar.