Fire Protection - HVAC– Rectangular and Square Ducts
 
Welded pin fixing method

Attachment by welded pins allows extremely rapid installation with slab joints simply butted together.
Welded pins are generally spaced at 350mm maximum centres along the length of the duct and at at 500mm maximum centres across the width and depth of the duct. Pins are required on all four sides of vertical ducts, but may be omitted from the top face of horizontal ducts (See datasheet).

Longitudinal corner joints fixed with pigtail screws at 250mm maximum centres (screw length to be 2 × slab thickness). Side wall slabs must overlap top and bottom slabs (as shown). Cross joints
bonded with FirePro Glue.

Alternative joint methods

Instead of pigtail screws, longitudinal joints can be fixed with FirePro Glue and nails, at 500mm max. centres.

Instead of glue, cross joints can be protected with centrally positioned, 100mm wide Fire Duct strips fixed along both edges with pigtail screws at 250mm max. centres.

Mitre-joint fixing methods

The use of mitre-joints at slab corners allows installation in situations where welding may not be practicable.

Nails are generally spaced at 500mm maximum centres.
See ‘Fire resistance’ table on page 40 for limitations on duct sizes.

Mitre-joint method
All joints bonded with FirePro Glue. Longitudinal corner joints secured with nails while FirePro Glue cures.