Intumescent Fire Block – Square

Square intumescent fire blocks provide a discreet form of fire protection for air transfer openings and grille apertures in fire-rated walls and partitions. In normal use the open honeycomb structure lets air pass through freely; when exposed to the heat of a fire, the intumescent material expands rapidly to seal the opening and resist the passage of fire.

We stock eight square sizes from 150mm × 150mm up to 500mm × 500mm (150, 200, 250, 300, 350, 400, 450 and 500mm), so you can match the block to your grille or transfer opening:

• 150 × 150mm, 200 × 200mm, 250 × 250mm, 300 × 300mm
• 350 × 350mm, 400 × 400mm, 450 × 450mm, 500 × 500mm

Intumescent blocks are a popular alternative to a mechanical damper for door grilles and wall transfer openings where no ductwork is connected. Where a duct passes through the fire barrier, use a rectangular fire damper or FD-C circular fire damper instead. Stocked sizes ordered by 3pm are dispatched for next-day delivery.