PROTECTION OF RECTANGULAR HORIZONTAL SHEET METAL VENTILATION DUCTS WITH FIBROGAINE®

DUCTS TESTED ACCORDING TO NF / EN 1366-1 – CLASSIFICATION ACCORDING TO NF / EN 13501-3

Rectangular horizontal Fibrogaine
Protection au feu des conduits de ventilation ou de désenfumage
Diagram 1.1
Diagram 2.1
Diagram 3.1

AREA OF VALIDITY:

  • Rectangular horizontal ducts
  • Cross section between 0 x 0 mm and 1250 x 1000 mm (l x h)
  • Maximum section length: 1400 mm
  • Duct sheet metal thickness
  • Maximum centre-to-centre spacing of support systems: 1200 mm
  • Width 625 mm, without duct reinforcement
  • FIBROGAINE® density: 209 kg/m3 ± 15 %
  • Negative/positive pressure: ± 500 Pa

 

DUCT INSTALLATION PRINCIPLE:

The duct is composed of sections with a maximum length of 1400 mm. These elements are joined with flanges attached together with M8 nuts and bolts on the edges and anchor bolts spaced 350 mm apart around the duct. The section joints are sealed using an A1 acrylic sealant. The duct body is supported with 1200 mm spacing (see diagram 1).
The support system is composed (see diagram 2) of a 41 x 41 perforated crossbar and two threaded rod hangers.

  • For 625 mm duct widths, reinforcement is not necessary.
  • For duct widths > 625 mm, ducts must be equipped with bracings (internal or external) (see diagram 3):
    –  Internal bracings composed of 13 x 17 mm (Ø int x Ø ext) steel spacers positioned lengthwise in the sections at mid-width and with 470 mm centre-to-centre spacing.
    – External bracings composed of U-shaped 25 x 50 x 25 mm profiles positioned at mid-length of the sections (max. 700 mm between bracings or flanges) and attached to the perimeter of the duct using 35 mm self-tapping screws spaced 225 mm apart.

PROTECTION INSTALLATION PRINCIPLE:

Duct body protection

  • A first layer approximately 30 mm thick of FIBROGAINE® is applied to the duct (without primer).
  • A 25 mm hexagonal grate (Ø = 0.8 mm) is then installed all around the duct.
  • A second layer of FIBROGAINE® is applied to achieve the desired final thickness.

Protection of support systems

The crossbar is encased in the duct body protection. The threaded rods can be protected by a rock wool shell (30 mm, 65/70 kg/m3) as well as FIBROGAINE® or by installing a grate and applying FIBROGAINE®. In both cases, the total thickness of the protection (shell + FIBROGAINE® or FIBROGAINE® only) will have a thickness identical to that applied to the duct.