Rockwool DuoDuct Slab


DuoDuct is a non-combustible stone wool slab which provides thermal insulation to external ducts carrying warm air, chilled air or dual purpose duct systems.

The insulation is designed for use with rectangular or square external ducts to withstand service temperatures of up to 230°C.

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DuoDuct is a non-combustible, Dual-Density stone wool slab with an aluminium foil facing bonded to the outer surface.

The robust outer layer provides a suitable surface for the application of insulation cladding systems.


DuoDuct has been designed for use with rectangular and square external duct work carrying warm air, chilled air or dual purpose duct systems. DuoDuct is recommended for ductwork with service temperatures up to 230°C.

DuoDuct is also suitable for use within plant rooms, low level plant work applications and areas where there is an increased risk of impact damage.

Circular Ductwork

In addition to DuoDuct Slab for rectangular or square external ductwork, ROCKWOOL offer a range of products that are suitable for use on circular external ductwork and this includes.

• RockLap H&V Pipe Sections which are suitable for outside diameters ranging from 17-406mm
• Pipe Section Mat which is suitable for larger circular ductwork ≥ 406mm For further information  on suitable external finishes for both RockLap and Pipe Section Mat please refer to the HVAC Specification Guide and the relevant datasheets which are available at


Standards and approvals DuoDuct has been CE marked in accordance with BS EN 14303. To download a copy of the Declaration of Performance please visit

DuoDuct can be used to satisfy the requirements of BS 5422 ‘Method for specifying thermal insulating materials’.


ROCKWOOL DuoDuct achieves a Reaction to Fire classification of A1 as defined in BS EN 13501:1.


For details on thermal conductivity, please contact Rockwool Technical Support. The maximum service temperature is 230°C in accordance with EN 14706: 2012.


It is sometimes desirable to improve the acoustic insulation on duct systems, especially those in which gases, fluids or particle solids are transported at high velocities.

The use of ROCKWOOL DuoDuct can considerably improve the level of environmental sound.

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