Cap End and Terminals
Cap ends and terminals for finishing spiral duct runs — whether that means blanking a duct off completely, screening an opening against birds and vermin, or terminating an extract discharge above the roof. Every terminal here matches our galvanised spiral ducting diameter series.
Choosing the right termination
- Cap ends (80mm to 1000mm) blank off a duct completely — for capped spare branches, future extensions and test points.
- Cap ends with mesh (80mm to 800mm) close the duct while letting air through — a simple screened terminal for intakes and discharges.
- Bird beaks with mesh (80mm to 1000mm) angle the opening downwards so rain runs off, with mesh keeping wildlife out — the standard wall termination for extract and intake duct.
- Jet cowls (250mm to 1000mm) throw the discharge upwards at velocity — the right finish for kitchen and fume extract stacks that must clear the air away from the building.
- Weather hats (100mm to 630mm) cap a vertical duct against rain while air escapes around the skirt — the classic roof termination for general ventilation.
Matching terminal to duty
Two questions pick the right terminal: does air need to pass, and which way does the duct face? A blanked branch takes a plain cap end; a screened opening in a sheltered position takes a mesh cap; a wall penetration exposed to weather takes the bird beak; and vertical stacks take a weather hat for general ventilation or a jet cowl where the discharge must be thrown clear. All are galvanised to match the ductwork and fit the standard spiral series, so upgrading a termination later is a straight swap. Pair roof terminations with a Master Flash roof flashing for a weathertight penetration. Stocked sizes ordered by 3pm are despatched next day, with free UK mainland delivery over £400 ex VAT.
