The Manrose Aluminium Flexible Ducting 100mm is a semi-rigid, corrugated aluminium duct hose that extends to a 3-metre working length and is supplied compressed for ease of handling and storage. Ideal for connecting extractor fans, cooker hoods and tumble dryers to external wall outlets, it offers significant advantages over PVC flexible duct where higher temperatures are expected or where fire compliance is a consideration. The aluminium construction does not release toxic gases in the event of fire, and the corrugated structure allows the hose to be bent to tight radii to navigate obstacles in wall cavities, ceiling voids and roof spaces. Compatible with all standard 100mm round duct fittings.
100mm
Duct diameter
3m
Extended length
Aluminium
Material
Semi-rigid
Construction type
3 Years
Warranty
Compressed for Easy Handling: The duct is supplied in its compressed state (approximately half its extended length) for easier transit and storage. Extend to the required length during installation — cut between corrugations with tin snips or sharp scissors if a shorter run is needed. The corrugated structure maintains a constant cross-section through bends, providing predictable airflow characteristics.
Installation Best Practice: Install as straight and fully extended as possible — compressed or kinked aluminium duct significantly increases air resistance and reduces fan performance. Each 90° bend adds the equivalent of approximately 1 metre of straight duct in pressure drop. Secure both ends with jubilee clips or aluminium foil duct tape for a vibration-free, airtight connection.
No Toxic Gases in Fire
Unlike PVC flexible ducting, aluminium duct does not release toxic gases or significant smoke when exposed to fire. This makes it the preferred material for ducting in roof spaces and wall cavities where fire spread via the duct run is a consideration, and in applications (such as cooker hood exhausts) where heat and grease vapour are present.
Higher Temperature Tolerance
Aluminium has a much higher thermal tolerance than PVC — making the Manrose 1010 suitable for cooker hood exhaust connections, tumble dryer vents and other applications where duct air temperatures exceed 60°C (the PVC limit). The metal construction also conducts heat away, preventing the duct itself from becoming a fire hazard at connections.
Corrugated Semi-Rigid Form
The corrugated spiral construction gives this duct its semi-rigid character — it holds its shape when bent and does not spring back or collapse under pressure, unlike smooth-bore flexible duct. Bend radii of less than half the duct diameter (½D) are achievable, allowing tight corners in confined spaces such as between stud walls or above suspended ceilings.
Universal 100mm Compatibility
Compatible with all standard 100mm round duct spigots and fittings, including extractor fan outlets, inline duct connectors, wall outlets and gravity flaps. The hose end simply slides over or into a 100mm spigot and is secured with a jubilee clip. It is the direct aluminium equivalent to PVC flex in all standard 100mm duct system configurations.
Technical Specifications
| MPN |
1010 |
| Brand |
Manrose |
| Duct Diameter |
100mm (4") |
| Extended Length |
3000mm (3m) |
| Construction |
Corrugated semi-rigid aluminium spiral |
| Material |
Aluminium |
| Colour / Finish |
Silver (aluminium) |
| Supply State |
Compressed (approx. 1.5m) — extends to 3m |
| Connector Type |
Round female fittings (100mm) |
| Wall Cut-Out Diameter |
112mm |
| Application |
Fans, cooker hoods, tumble dryers, ventilation |
| Fire Behaviour |
No toxic gas emission in fire |
| Warranty |
3 years (Manrose) |
Frequently Asked Questions
What is the difference between aluminium and PVC flexible ducting?
Aluminium ducting tolerates higher temperatures (suitable for cooker hoods and tumble dryers), produces no toxic gases in fire, and has a longer service life in damp or high-temperature environments. PVC flexible ducting (such as Airvent 401897) is lighter, more flexible and slightly cheaper, but is limited to a maximum 60°C operating temperature and is not recommended for cooker hood exhaust applications. For bathroom and utility fan connections where temperature is not a concern, either material is acceptable; for cooker hood or tumble dryer ducts, always choose aluminium.
How do I cut aluminium flexible ducting?
Use tin snips or sharp heavy-duty scissors to cut between the corrugation ridges. Avoid cutting through a ridge as this leaves a sharp raised edge. After cutting, fold the cut end's corrugation over slightly with pliers to create a smooth edge that will not cut through ducting tape or jubilee clip rubber inserts. Seal the cut end immediately to prevent unravelling of the spiral.
Why does the duct come compressed rather than extended?
The duct is compressed to approximately half its 3m extended length (~1.5m) for packaging and transport efficiency. During installation, simply extend it to the length needed. Avoid stretching beyond the full 3m as this reduces wall thickness and structural integrity. Once installed, the corrugated walls hold their position and the duct does not recompress under normal operating conditions.
What size core drill do I need for a 100mm duct run through a wall?
The recommended wall cut-out for the 100mm duct system is 112mm. This allows the duct to pass through without compressing, and leaves a small gap around the perimeter for acoustic and thermal sealant. Use a 112mm core drill bit (SDS or diamond, depending on wall type). After routing the duct, seal around the penetration with a fire-rated acoustic sealant or a purpose-made wall sleeve to meet Part F and fire separation requirements.
