Aluminium Stair Nosing 91mm Chevron Twin Insert, 70mm Riser, 2.44m & 3.22m

The largest chevron profile in the heavyweight aluminium stair nosing range: a 91mm tread plate on a 70mm kinked front face, extruded in a 5mm gauge to bed down over medium weight carpet or heavy duty smooth flooring. Two PVC insert channels run the length of the plate, split by a bare metal rib. The chevron face is the reason to choose it: the manufacturer describes chevron fronted profiles as suitable for narrow bullnose or square fronted staircases, the part-rounded step edge a plain square nosing will not sit against. Six metal finishes, nineteen insert colours, 2.44m and 3.22m bars.

Why it works

A 70mm face on a stair that is not square

Most double channel nosings stop at a 40mm or 55mm riser. This one drops 70mm, and the lower part of the face angles back into a chevron, so it follows a rounded or chamfered step front and still finishes tight to the riser, where a square profile would leave a wedge of daylight behind the leg.

The 5mm gauge is a carpet allowance

The manufacturer specifies the 5mm gauge for medium weight carpet and heavy duty smooth flooring: the plate sits over the covering and still presents a flush leading edge. The plate is aluminium alloy; the PVC inserts are pressed in after the bar is screwed down, covering the fixing heads.

Two channels, and a reason to use two colours

Because a bare metal rib separates the bands, you can run two different inserts along one step: dark against pale, or Hazard against a neutral. Approved Document K asks for a visually contrasting nosing material a minimum of 55mm wide on both tread and riser in buildings other than dwellings; here the two bands cover well over 55mm of the 91mm tread and the 70mm metal face gives you the riser width too. Approved Document M sets the threshold as a light reflectance value difference of more than 30 points, and the manufacturer publishes an LRV for every plain insert colour, from Premium Black at 4.48 to White at 73.69, so you can specify the contrast rather than guess it.

The slip figure, and what it applies to

The manufacturer's safety documentation pack carries a pendulum test to BS 7976-2 by Floor Safe Ltd, report FS10174, Four-S slider: 70 PTV dry and 58 PTV wet, both low slip potential on the HSE scale. The sample is "Stair Tread - Linished", the metal surface, so treat it as a figure for the profile rather than a per-colour insert rating. No R value and no fire rating are published for the standard PVC insert.

Where it's used

Internal commercial and public stairs where the step front is rounded or chamfered: older office and civic buildings, schools, hospitals, hotels, theatres and shared-access residential cores, and refurbishments of concrete or terrazzo flights where the worn nosing is renewed without lifting the covering.

Specifications

Choosing the right option

Start with the step edge. Choose this chevron when a square double channel nosing will not sit tight to a rounded or chamfered step front. Steps with a clean 90 degree arris take a square profile for less money; a full, deep bullnose wants a purpose-made bullnose profile.

Then the riser depth. At 70mm this is the deepest chevron in the range; the same double channel plate is also made with a 40mm or 60mm riser, and there is a single channel chevron with a 65mm riser. Pick 70mm when the metal face itself must give the 55mm of riser contrast Approved Document K asks for.

Finish and length set the price; insert colour does not, with Hazard the one exception. Mill Finish is the plain, lowest-cost option; Bright Polished and the golds suit foyers and hotels; Satin Black and Dark Bronze sit quietly in darker interiors. Special finishes are made to order, so talk to us before committing on a deadline. Check the LRV of your tread covering and choose an insert at least 30 points away from it. Order the length above your widest step and cut down on site.

Installation, use and care

Follow the manufacturer's installation guide: make the step flat, clean and dry, push the bar hard against the riser while marking through the drill holes, drill and plug, apply cartridge adhesive to the underside, screw down firmly and press the insert plugs over the screw heads. Cut with a fine-tooth blade suited to aluminium and deburr. The manufacturer's maintenance sheet says clean weekly with a mild detergent on a damp cloth; no polishes, which reduce the anti-slip properties, no solvent or strong detergents, no steam cleaners or pressure washers.

Frequently asked questions

Ordering and delivery

Choose finish, insert colour and length above and order one bar per step. This profile is supplied to order from the manufacturer; we confirm the lead time when you order. For the 2.75m length, an unlisted finish, or two insert colours in one bar, contact us before you commit.