Semi-Rigid Flex

Semi-rigid flexible ducting — the flex that holds its shape. Supplied in 3m lengths and 10 diameters from 100mm to 355mm, semi-rigid duct bends by hand to the route you need and then stays put, giving a smoother, more open bore than fabric-and-wire flexible ducting and better airflow to match.

The best of both worlds

Standard flexible duct sags, ripples and robs airflow; rigid duct needs fittings for every change of direction. Semi-rigid flex (3m long) splits the difference: form it around obstacles once, and it behaves like rigid duct thereafter — no sag between supports, no collapsing on tight bends, and a bore that stays round. That makes it a favourite for cooker hood and tumble dryer runs, loft ductwork, and light commercial extract where performance matters but full rigid installation is impractical.

Diameters stocked: 100, 125, 150, 160, 180, 200, 250, 300, 315 and 355mm, connecting directly to fans and spigots of the same size (use a male connector where it meets plain spiral duct).

Where semi-rigid earns its premium

Any run where standard flex would sag or kink is semi-rigid territory: cooker hood extracts through cupboards, tumble dryer vents, loft runs to an eaves or roof terminal, and light commercial connections where the fan needs every pascal it produces. Because the duct holds a round, open bore through every bend you form, performance stays predictable — no hidden flat spots throttling the system after the ceiling closes up. Form the route once, support long spans, trim to length and clamp the joints with hose clips. Stocked sizes ordered by 3pm are despatched for next-day delivery, with free UK mainland delivery on orders over £400 ex VAT.