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Designed for use with rectangular and square external duct work carrying warm air, chilled air or dual purpose duct systems. Recommended for ductwork with service temperatures up to 230°C.

The slab 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 17–406 mm. Pipe Section Mat which is suitable for larger circular ductwork ≥406 mm.


A dual-density stone wool slab with an aluminium foil facing bonded to the outer surface. The robust outer layer provides enhanced impact resistance and a suitable substrate for surface applications such as cladding.

Designed for use on rectangular or square external ductwork, ROCKWOOL DuoDuct is suitable for insulating cold air, hot air and dual-purpose duct systems – withstanding service temperatures of up to 230°C. The slabs are easy to cut and quick to install, allowing for increased efficiency on site. 

Where duct systems require acoustic insulation, DuoDuct Slab supports a reduction in the level of environmental sounds. This is particularly useful where duct systems are carrying gases, fluids, or particle solids at high velocities. 

In addition to DuoDuct Slab for rectangular or square ductwork, ROCKWOOL also offers a range of products for use on circular ductwork, including RockLap H&V Pipe Sections and Pipe Section Mat. 

Features and benefits:

  • Euroclass A1 non-combustible.
  • Sound absorbent.
  • Suitable for use with self-adhered external duct membranes.
  • Dual Density technology provides impact resistance.
  • Easy to cut and quick to install.
  • CE Marked to BS EN 14303:2009 +A1:2013.

General information


Stone wool




2000 mm


1200 mm


50 mm


Pr_80_77_76_53 Mineral wool duct slab insulationPrimary


U90/490 Site-applied insulation to ductwork

Specification data - Mineral wool duct slab insulation


To BS EN 14303, BS 5422 and EN 14706: 2012.


Flexible slabs.



Reaction to fire classification

Euroclass A1 non-combustible.

Insulation thickness (minimum)

50 mm.


Installing mineral wool lamella insulation on ductwork.

Water vapour resistance

1000 MNs/g.



1200 x 2000 mm.

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