Slip-resistant wood stair nosings & LRV requirements

A wood stair edge is only as safe as its grip and its visibility. Two measured values describe those two things: the Pendulum Test Value (PTV) for slip resistance, and the Light Reflectance Value (LRV) for how clearly each step edge stands out. This guide explains both in plain English, what the UK guidance asks for, and how to hit the numbers on a timber staircase.

The two numbers that matter

Slip resistance and visual contrast are measured separately and you need to think about both. A beautifully contrasting nosing that is slippery underfoot is still a hazard; a grippy edge that blends into the tread is easy to misjudge on the way down. Aim to satisfy both.

Slip resistance: Pendulum Test Value (PTV)

Slip resistance is measured with a pendulum test, which gives a Pendulum Test Value (PTV). The widely accepted benchmark, set out by the UK Slip Resistance Group and used by the HSE, is a PTV of 36 or more in both wet and dry conditions for the tread/nosing surface.

The HSE slip-potential bands are a useful way to read the number:

• 0–24 — high slip potential
• 25–35 — moderate slip potential
• 36 and above — low slip potential

For stairs that get wet, greasy or very heavy use, many specifiers aim higher still — 40+ as a comfortable margin, and 65+ where oil, grease or food waste is likely.

How to reach PTV 36+ on a wood nosing

Bare, sealed timber can be slippery, especially in socks or when wet, so grip usually comes from a non-slip insert set flush into the leading edge rather than from the timber itself. Our nosings take three insert materials:

• Carborundum — a gritted insert giving the highest grip; the go-to where safety leads
• Composite rubber — resilient and quieter underfoot, a good all-round choice
• Solid brass — a decorative, hard-wearing option with period character

Compare the three in our guide to non-slip stair edges.

A word on “R ratings”

You will often see floor and nosing products quoted with an R rating (R10, R11 and so on). That scale comes from a German oil-ramp test (DIN 51130), not the UK pendulum test, and it does not map reliably to PTV — a single R10 product can span a wide range of pendulum results. For UK stairs, ask for a measured PTV, wet and dry. On an already-fitted stair, where there is no room to swing a pendulum, a surface-roughness reading (Rz of around 20µm) is the usual on-site check.

Visual contrast: Light Reflectance Value (LRV)

LRV measures how much light a surface reflects, on a scale from 0 (black) to 100 (white). Making each step edge visible is about the difference in LRV between the nosing and the tread behind it, not the colour itself.

BS 8300-2:2018 — the accessibility standard referenced by Approved Document M — describes adequate visual contrast as a difference of at least 30 points on the LRV scale between the nosing and the surrounding step. It is guidance rather than legislation, but it is the figure specifiers work to.

Approved Document M (for buildings other than dwellings) also expects step nosings to be made visually apparent with a contrasting material forming a band at least 55mm wide on both the tread and the riser.

A worked example

Say your treads have an LRV of 55. To clear the 30-point difference, the nosing needs an LRV below about 25 (noticeably darker) or above about 85 (noticeably lighter). A mid-brown nosing on a mid-brown tread will often look different to the eye while measuring far too close — which is exactly why you measure rather than eyeball it, and ask suppliers for measured LRV figures.

How we help you hit the contrast

Because our wood nosings are colour-matched to order, we can finish the edge deliberately darker or lighter than your floor to land the LRV difference you need — rather than hoping an off-the-shelf shade happens to contrast. Tell us the tread finish (or its LRV) and the target, and we will match to it.

Putting it together on a timber staircase

Is any of this a legal requirement?

For dwellings, stair geometry sits under Approved Document K, which does not set a slip or LRV value for nosings. The 30-point LRV contrast and the 55mm band come from BS 8300 and Approved Document M, which apply to accessibility in buildings other than dwellings; PTV 36+ is an industry/HSE benchmark rather than a figure written into those documents. See our plain-English guide to Part K and Part M. For a formal compliance submission, always confirm the exact wording in the current BS 8300-2:2018 and Approved Document M.

Our solid wood stair nosings can be supplied with any of the three non-slip inserts and colour-matched to the contrast you need — cut to length and made to order.