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Intumescent fire-stop block

Product 2


Intumescent blocks for fire-stopping gaps around services

Not available to purchase online.

Please contact us on +44 (0) 1 304 842 555 to order.


A fire resistant mineral fibre block which can be used as a temporary or permanent fire stopping method in walls or floors. Clad with foil and intumescent strips, the block expands in opposite directions in a fire, locking in place and sealing the void.


– Great for fire-stopping voids in compartmentalised walls and floors- Easily installed around existing services and can be cut to shape to accommodate new ones

– Can be used in conjunction with intumescent wraps or collars to provide 2 hours protection or more for services passing through walls and floors

– Can be used between screen walling and concrete floors as a firebreak

Application Instructions

The Intumescent Blocks can be cut with a sharp knife or hacksaw blade, fitting into
the opening to form a fire seal. Can be cut and pushed around services and pipes.
Where plastic pipes are 75mm or over then use Envirograf Wrap or Pipe Sleeve
fixing into the blocks. Where blocks are going over cable trays, leave a small gap and
use Envirograf Product 29 Cable Tray Pillows. The blocks have double-sided tape
around the edges so they can be adhered to each other to form a smoke seal. Where
there are any open joints use Envirograf Product 63 Intumescent Cement Filler of
Product 61 CS Stopper.
Envirograf Intumescent Blocks can be used between screen walling and concrete
floors as a firebreak.

Order References / Sizes

REF                        SIZE                                                       LENGTH                PROTECTION                                                      

IB1                           50mm thick x 150mm wide             1200mm                               1 hour

IB1/A                       50mm thick x 100mm wide             1200mm                               1 hour

IB1/B                       50mm thick x   50mm wide             1200mm                               1 hour

IB2                          100mm thick x 150mm wide            1200mm                               2 hours

IB2/A                      100mm thick x 100mm wide            1200mm                               2 hours

IB2/B                      100mm thick x   50mm wide             1200mm                               2 hours