Plaster-In LED Profile
A plaster-in LED profile is an aluminium channel with perforated flanges that is fixed to plasterboard and skimmed over, so the plaster finishes hard against the diffuser and the finished light line sits flush with the surface — no visible bezel, trim or fixing. UNO stocks the trimless range in 12mm and 20mm internal widths, from £13.20 for a 2-metre length with a frosted diffuser and end caps included, plus cove, corner, shadow-gap and flexible profiles for detailed and curved work. The profile houses an LED strip, which is bought separately so the extrusion can be specified around the architecture and the strip around the lighting design. Stocked items are usually delivered within 1–3 working days from the UK.
- 12mm & 20mminternal widths
- From £13.202-metre length
- 1–3 daysUK delivery on stock
- 6063 alloyaircraft-grade, stays rigid
What a plaster-in profile is
Plaster-in profile, plaster-in channel, trimless profile, plasterboard LED profile — all the same thing: an extrusion designed to disappear into the ceiling. The flange along each edge is perforated so plaster keys through it, which is what lets the skim finish hard against the diffuser rather than against a visible frame.
It is the detail specifiers reach for when they want the light and not the light fitting.
The strip is separate
The profile does not light on its own. It houses an LED strip, chosen for the output and colour temperature the room needs.
That separation is deliberate: spec the channel around the architecture and the strip around the lighting design — and the strip can be replaced years later without touching the plaster.
Comparing the plaster-in range
| Profile | Internal width | Diffuser | Price | Typical use |
|---|---|---|---|---|
| Trimless 12mm | 12mm | Frosted | £13.20 | The standard flush ceiling and wall line |
| Trimless 20mm | 20mm | Opal | £18.99 | Wider strips, higher output, longer runs |
| Trimless 12mm black | 12mm | Black + frosted | £24.50 | Dark ceilings and shadow details |
| Shadow gap / edge | 12.5mm | Opal | £26.97 | Shadow-gap and tiled-edge details |
| Flexible | 12.5mm | Silicone opal | £25.99 | Curves, arches and radiused walls |
| Corner 48 x 27mm | 12.6mm | Opal PC | £34.19 | Wall-to-ceiling junctions |
| Cove 98 x 19mm | 11.6mm | Opal PC | £47.06 | Slim cove and indirect uplighting |
| Cove 85.5 x 56.7mm | 21.3mm | Opal PC | £59.14 | Deep cove details, higher output |
For longer continuous runs the 12mm comes in multipacks: 2-pack, 4 metres, £26.39 · 5-pack, 10 metres, £65.99.
Fitting: before the ceiling is skimmed
The sequence matters more than anything else on this product. The profile goes in while the plasterboard is up but before the skim coat, so the plasterer can work the finish right up to the diffuser edge.
Fix the extrusion to the board along the run and check it is dead straight — a plaster-in line shows every deviation once it is lit. Let the plasterer bed the flange in, then fit the diffuser and the strip after the plaster has dried.
The mistake that ruins the job
Wet plaster migrating into the channel during skimming. A foam filler strip sits in the profile while the plasterer works and lifts out afterwards, keeping the channel clean for the strip.
Square filler, 12mm — £10.99
Round filler, 20mm — £11.99
The cheapest insurance on the whole installation.
Choosing a width, a diffuser and a strip
Width
Match the profile's internal width to the LED strip, not the other way round. The 12mm takes a strip up to 12mm and handles most ceiling and wall runs. The 20mm takes wider, higher-output strips. A strip even fractionally too wide will not seat.
Diffuser
Frosted diffusers on the 12mm give a softer line and hide individual LEDs well at normal viewing distance. Opal diffusers on the wider and cove profiles diffuse more heavily — which matters when the strip sits close to the face, or the run is viewed straight on. Spare diffusers, £3.50.
Curves and detail work
The shadow-gap edge profile suits a tiled or panelled edge. The corner profile resolves a wall-to-ceiling junction without a separate trim. The cove profiles throw light up and back for indirect schemes. For arches, the flexible profile bends to a radius.
Frequently asked questions
What is a plaster-in LED profile?
A plaster-in LED profile is an aluminium channel with perforated flanges that is fixed to plasterboard and skimmed over, so the plaster finishes hard against the diffuser. The result is a flush line of light with no visible bezel, trim or fixing. It houses an LED strip, which is chosen separately for output and colour temperature.
When do you fit a plaster-in profile?
Before the ceiling or wall is skimmed. The profile is fixed to the plasterboard first so the plasterer can bed the flange in and finish up to the diffuser edge. The diffuser and the LED strip go in after the plaster has dried. Fitting one to an already-skimmed ceiling means cutting the finish open.
What width plaster-in profile do I need?
Match the profile's internal width to your LED strip. The 12mm profile suits strips up to 12mm and is the standard choice for most ceiling and wall runs. The 20mm profile takes wider, higher-output strips and suits longer runs. Check the strip width before ordering, as a strip that is even fractionally too wide will not seat.
Do I need foam filler with a plaster-in profile?
It is strongly recommended. Foam filler sits in the channel during skimming and stops wet plaster migrating inside, which is the most common cause of a ruined installation. UNO stocks square filler for the 12mm profile at £10.99 and round filler for the 20mm at £11.99.
Can you get a plaster-in profile for a curved wall?
Yes. The flexible plaster-in profile with a silicone opal diffuser (£25.99, 12.5mm internal width) bends to follow arches, curves and radiused walls while keeping the same trimless plastered-in finish as the rigid channel.
Does the LED strip come with the profile?
No. The profile is supplied with its diffuser, end caps and fixing accessories; the LED strip is bought separately. This is deliberate, so you can specify the extrusion around the architecture and the strip around the lighting design, and replace the strip later without disturbing the plaster.
How long does delivery take?
Stocked plaster-in profiles are usually delivered within 1–3 working days from the UK. Bespoke LED strip lengths are available to order — email your requirements to sales@uno-lighting.com.
What do people search for?
Plaster in led profile, led plaster in profile, plaster in profile, plasterboard led profile, led profile channel, recessed led profile, trimless profile, led coving, plaster in led channel, aluminium led profile, led strip channel.
Ready to order?
Measure the run, pick the width, add foam filler for the skim stage, and choose your strip separately. For bespoke LED strip lengths, email sales@uno-lighting.com.
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