Square DDA Aluminium Stair Nosing 56 x 56mm, Exterior Grip Insert

This is the DDA square nosing with exterior-grip inserts: 56mm across the tread, 56mm down the riser, carrying a gritted exterior-grip insert faced with a hard mineral grit. It is made for steps that get wet, dirty or gritted, where a smooth PVC insert would be the wrong choice.

The profile is aluminium with a 3.5mm gauge for vinyl, lino and lightweight carpet. Choose from three insert colours and five finishes, in three stock lengths.

Why this profile works

Grit, not plastic

Equal 56mm legs put a band of contrast on the tread and the riser, which is what accessibility guidance asks for on a stair people have to read at a glance. The grit face keeps working when the surface is wet, which is exactly when a step edge matters. When the inserts eventually polish down under heavy traffic, they are replaced on their own and the aluminium stays where it is.

A 3.5mm gauge sets the floors it suits

The gauge is the depth your floorcovering meets behind the nosing. At 3.5mm it lines up with vinyl, lino and lightweight carpet, so the covering finishes flush with the back of the profile and nothing catches underfoot.

Sized for contrast on tread and riser

This profile comes from the DDA range, sized to carry a permanently contrasting band on both the tread and the riser, which is what Approved Documents K and M and BS 8300 ask for on accessible stairs. Compliance still depends on the insert contrasting with your floor, usually judged on light reflectance value (LRV), so choose the colour with that in mind.

• Square edge aluminium profile, 56mm tread x 56mm riser, 3.5mm gauge
• One insert channel with replaceable gritted exterior-grip inserts
• 3 insert colours: Brimstone (safety yellow), Coal (black) and Everest (light grey)
• 5 finishes and 3 stock lengths (2.44m, 2.75m, 3.22m)

Where it's used

Covered entrance steps, fire escapes and external stairs at offices, schools, hospitals, shops and leisure centres; loading bays, plant rooms and service stairs; and any internal stair where spillage, grit or wet footfall makes a smooth insert too slippery, such as a kitchen or workshop entrance.

Specifications

Choosing the right option

Insert colour. Brimstone is safety yellow and the most visible; Coal is black and the most discreet on concrete; Everest is light grey and reads well on dark surfaces. Choose for contrast against the step, not to match it.

Finish. Mill Finish is plain untreated aluminium and the most economical for service and back-of-house steps. Satin Gold, Dark Bronze and Satin Black are coloured finishes for front-of-house entrances. Mirrorflect Gold is mirror-bright and the most expensive. Bright Polished is not offered with exterior grip inserts.

Length. Order the stock length that cuts into your step widths with the least waste, and allow a spare where widths vary.

Installation, use & care

Cut to each step width with a fine-toothed saw for aluminium and de-burr the ends. The step must be sound, clean and dry. Fix by screwing through the tread leg with fixings suited to the substrate, bedding the profile on a suitable exterior-grade adhesive so water cannot track underneath. Lay the floorcovering up to the back of the profile, then press the inserts fully home. Sweep or wash the grit face regularly: mud and leaf litter clog the texture, and a clogged insert stops gripping.

Frequently asked questions

What makes these inserts different from the PVC ones?

Exterior grip inserts are faced with a coarse mineral grit, like a very hard wet-and-dry paper, instead of a smooth PVC surface. That texture keeps its grip when the step is wet, which is why it is specified on covered entrances, fire escapes and service steps. Smooth PVC inserts are the internal option.

Can they be used on fully open outdoor steps?

They are made for external use and are normally fitted on covered or sheltered steps: entrances under a canopy, fire exits, loading bays and walkways. On a fully exposed flight, standing water, ice and grit take their toll on any nosing, so check drainage and expect to clean the inserts regularly.

Which insert colour should I choose?

Pick against the floor and the light. Brimstone (safety yellow) gives the strongest warning and suits service and plant areas. Coal (black) is the discreet choice on grey concrete. Everest (light grey) suits dark stone and asphalt. Contrast is what makes the step edge readable, so avoid matching the insert to the surface.

How many steps will one length cover?

Each length is cut to your step widths on site. Divide the length by your step width, allowing a few millimetres per cut. The three stock lengths are 2.44m, 2.75m and 3.22m: pick the one that cuts with the least waste.

Ordering & delivery

Each variant is one length in your chosen finish, insert colour and stock length, inserts supplied. Order one length per group of steps it cuts into. Screws and adhesive are not included. We deliver to UK mainland addresses, with lead time and carriage shown at checkout.