Stair Nosings For Carpet

Description

Carpeted stairs need a deeper profile than hard floors. The nosing has to accommodate the pile and any underlay so the carpet tucks in and finishes level with the top of the profile, rather than sitting proud and leaving a ridge at the step edge.

Get that depth right and you get a flush edge that holds the carpet firmly, protects the most heavily worn part of the stair, and stops the pile fraying back from the front of the tread — which is how carpeted stairs normally fail.

Measuring for carpet

The number that matters is the total build-up: pile depth plus underlay plus any adhesive or gripper. Measure it compressed rather than fluffed, because that is how it sits under foot.

• Domestic pile over underlay — usually 10–15mm total. Needs a deep channel or a generous return leg.
• Contract carpet, no underlay — typically 6–9mm. A shallower channel suits better; too deep leaves a void that collects grit.
• Carpet tiles — usually 6–8mm and dimensionally stable, so a slim profile works well.

Too shallow and the carpet sits proud, forming exactly the raised lip you were trying to avoid. Too deep and the edge is unsupported and crushes under traffic.

Profile types for carpet

• Single and double channel aluminium — the carpet dresses into the channel and the anti-slip insert sits proud of it. Double channel suits deeper treads and heavier traffic.
• Carpet clamp profiles — grip the carpet backing mechanically rather than relying on adhesive. The most secure option on a stair that sees dragging loads.
• Ramp-back profiles — the angled rear lets the carpet rise gently to the nosing rather than turning a hard corner, which reduces wear at the fold.
• PVC profiles — softer and quieter for domestic stairs, and more forgiving over an uneven edge.

Fixing through carpet

This is where carpet installations most often go wrong. Use screws long enough to pass through carpet and underlay into solid material. A fixing that only bites into underlay is no fixing at all — it will feel tight on the day and work loose within months.

Cut the carpet cleanly around the profile rather than forcing a tight fit, which causes bunching and a raised edge. Fit the nosing first and dress the carpet into it, rather than trying to slide a profile under carpet already laid tight to the edge.

Roughly 150mm centres on concrete, minimum three per step, always one near each end. Full method in our step-by-step installation guide.

Contrast and compliance

Carpet makes contrast harder, not easier — patterned and mid-tone carpets can measure very close to a nosing that looks quite different by eye.

• Approved Document M is the source of the 55mm × 55mm contrasting band across tread and riser, for buildings other than dwellings.
• BS 8300-2:2018, a standard referenced by Part M rather than law in itself, recommends at least 30 points of Light Reflectance Value difference between the nosing and the tread.
• Approved Document K covers stair geometry — going, rise, and nosing projection, 25mm being the figure to work to. It is not the source of the contrast requirement.
• Workplace (Health, Safety and Welfare) Regulations 1992, regulation 12 is the legal duty that floors are not slippery so as to expose anyone to risk.

Check the LRV figures rather than judging by sight — our LRV contrast calculator will test a combination before you commit.

Frequently asked questions

How deep a channel do I need for carpet?
Measure the compressed total of pile plus underlay. Domestic pile over underlay is usually 10–15mm, contract carpet without underlay 6–9mm, and carpet tiles 6–8mm. Match the channel to that figure rather than to the carpet alone.

Can I fit a nosing over carpet that is already down?
It is far better to lift the carpet at the step edge, fit the nosing, and dress the carpet back into it. Fitting over laid carpet means trimming in place and usually leaves a ragged line and a poor grip on the backing.

What screws should I use?
Long enough to pass through carpet and underlay and bite properly into the tread beneath. Countersunk, and stainless if the stair is anywhere damp. Screws that stop in the underlay will loosen.

Will the nosing stop the carpet fraying?
Yes, that is one of its main jobs. The profile caps the cut edge of the carpet so the pile cannot pull back from the front of the tread, which is the usual failure point on a carpeted stair.

Do carpeted commercial stairs still need contrast?
Yes. Approved Document M applies to the stair regardless of covering, and carpet often makes achieving 30 LRV points harder because the tread is mid-tone. Choose the nosing colour against the measured LRV of the carpet.

Which profile for carpet tiles?
A slimmer channel, typically 6–8mm, and ideally a clamp profile. Carpet tiles are dimensionally stable and do not need a deep return, but they do benefit from mechanical retention at the edge.

Supplied in stock lengths that cut to size with a hacksaw or chop saw. Fast UK delivery on stocked lines — call 01282 270 010 with your carpet and underlay thickness and we will match a profile to it.