Independent Acoustics and Noise Control Expertise Custom Audio Designs Ltd 

PyroJoint acoustic intumescent expansion gap sealerPyroJoint acoustic intumescent expansion gap sealerPyroJoint acoustic intumescent expansion gap sealerPyroJoint acoustic intumescent expansion gap sealerPyroJoint acoustic intumescent expansion gap sealer

PyroJoint - Acoustic / Intumescent Expansion Joint Seal

  • BS476: Part 20.
  • PR EN1336-4.
  • Up to 4 hours fire resistance.
  • Weather proof & water resistant.
  • Suits internal/external applications.
  • Cost effective to install.
  • Performance temperature between -30 to +130°C.

class0 expansion joint

The sub-division of compartments in a building - if effectively fire stopped - will prevent the spread of fire and smoke through fire resisting and separating elements. All expansion and movement joints in a fire separating wall and floor must be fire stopped with a proprietry material that will accommodate the require movement whilst providing the necessary degree of fire integrity.

The PyroJoint Intumescent Expansion Joint Seal is manufactured using various thickness of flame retardant open cellular foam, fire rated to achieve Class 1 and Class 0 when tested to BS476 Part 20. Expandable graphite based intumescent is factory sprayed onto both sides of the foam, forming a compressible fire resistant joint filler which is resistant to moisture attack.

The graphite based material starts to intumesce around 115°C on the fire side of the joint whilst the fire rated foam gradually compresses allowing the expanding mass of intumescent graphite to totally seal the opening.

This carbonaceous char formed by the graphite will prevent the spread of fire through the joint thus ensuring the integrity of the compartment wall/floor is maintained.

Areas of Use

  • Between steelwork and blockwork where deflection and movement could occur.
  • In movement joints with blockwork walls and floors.
  • Top of wallhead to the underside of the floor - although gaps could be uneven PyroJoint Intumescent Expansion Joint Seal is extremely compressible and should accommodate any irregularities.
  • Around mechanical services such as pipes and ductworks etc.
  • PyroJoint is an extremely versatile filler material.
intumescent expansion foamintumescent expansion foam

1 no. PyroJoint 20/120FR fire sealing a 15mm gap for 2hr
2 no. PyroJoint 20/60FR fire sealing the same size gap for 2hr.


Installation is easily effected by compressing the pre cut PyroJoint Intumescent Expansion Joint Seal and inserting into the joint and releasing. A minimum compression of 15% per thickness of material is recommended to ensure a rigid friction fit although it can be compressed to 50%.

Supplied in 1m lengths that can easily be butted together. Cutting can be done with a fine toothed hacksaw making sure that the ends are cut square.

If you have very rough concrete joints then we can supply a slightly different intumescent strip material which is designated 'FR-L'

Storage, Handling and Installation

  • Handle with care.
  • Compress and fit into the expansion movement joint.
  • The material will quickly recover and expand to fill the joint. There is sufficient pressure on recovery to wedge the joint without the need to use adhesive or mechanical fixing systems.
  • Use a fine tooth saw to cut to length.
  • Suitable for dry areas. In wet areas the open cell foam will absorb moisture.
  • For any further information or in case of difficulty please contact our technical department.
Gap WidthProduct Reference for gap size in relation to fire resistance.
 FR 60 MinsPart CodeFR 120 MinsPart Code
10mmPyroJoint 10/60FRPart Code FR100PyroJoint 10/120FRPart Code FR200
20mmPyroJoint 20/60FRPart Code FR110PyroJoint 20/120FRPart Code FR210
30mmPyroJoint 30/60FRPart Code FR120PyroJoint 30/120FRPart Code FR220
40mmPyroJoint 40/60FRPart Code FR130PyroJoint 40/120FRPart Code FR230
50mmPyroJoint 50/60FRPart Code FR140PyroJoint 50/120FRPart Code FR240
60mmPyroJoint 60/60FRPart Code FR150PyroJoint 60/120FRPart Code FR250
70mmPyroJoint 70/60FRPart Code FR160PyroJoint 70/120FRPart Code FR260
80mmPyroJoint 80/60FRPart Code FR170PyroJoint 80/120FRPart Code FR270
90mmPyroJoint 90/60FRPart Code FR180PyroJoint 90/120FRPart Code FR280
100mmPyroJoint 100/60FRPart Code FR190PyroJoint 100/120FRPart Code FR290

All information contained in these details is given in good faith but without warranty.
Custom Audio Designs reserves the right to alter the specifications of any product without notice.
©Custom Audio Designs