240min PROMATECT®-H cladding to steel ducts greater than 1500mm Width 3

System in accordance with the requirements of BS 476: Part 24: 1987 and/or AS 1530: Part 4: 2005

  1. PROMATECT®-H board with or without mineral wool, requirements in accordance with table below
  2. PROMATECT®-H cover strips, requirements in accordance with table below
  3. PROMATECT®-H collars 150mm wide, thickness in accordance with table at top right, fitted around the duct on both sides of the wall forming an L shape
  4. a. Galvanised steel channels minimum 50mm x 50mm x 0.9mm thick (except 50mm x 100mm x 0.9mm for 240/240/240 fire resistance) coinciding with board joints, spaced at centres in accordance with the duct width to ensure an unsupported area ≤ 15000mm2
    b. Additional support of galvanised steel channel at middle span of the duct (please consult Promat for construction details)
  5. Galvanised steel angles 30mm x 30mm x 0.8mm thick
  6. Steel rod hangers (download the borchure to consult the maximum stress allowance calculation)
  7. Galvanised steel channel or angle (download the borchure to consult the size calculation in accordance with weight and dimension of the duct and maximum stress allowance of the hangers)
  8. a. No. 8 self-tapping screws at nominal 200mm centres
    b. 50mm long No. 8 deep threaded drywall screws fixed board face to board edge with a minimum 25mm penetration or two times of the board thickness, whichever is greater (applicable for 20mm or 25mm thick boards only)
  9. Care should be taken not to overtighten the screws. When edge fixing it is advisable to drill pilot holes M8 anchor bolts at nominal 500mm centres
  10. Mineral wool tightly packed into aperture between substrate and surface of the mild steel ventilation duct