A false ceiling cove is a simple thing built badly more often than not. The strip is rarely the problem. The pocket is.
The design numbers
| Measurement | Target | Failure mode outside it |
|---|---|---|
| Cove lip below slab | 150–220mm | Hotspot instead of a wash |
| Clear pocket depth | 60–80mm | Source visible, glare |
| Strip setback from lip | 30–45mm | Hard bright line on the ceiling |
| Driver headroom | +20% | Driver overheats, fails early |
Clear depth means clear — measured with the aluminium profile in place, not the raw carpentry. A 15mm profile in a 70mm pocket leaves 55mm, and you are under spec without realising it.
Why coves look cheap
Three reasons, in order of how often they happen:
1. You can see the dots. Standard strip runs 320 LEDs per metre. From across a room, in a deep cove, that is fine. In a shallow cove, or anywhere the strip is visible at close range, you see individual diodes and the whole ceiling reads as cheap. COB at 480/m removes the dots entirely — the light source is continuous.
2. The colour is wrong. Ra80 strip renders roughly 80% of the colour information in a scene, and the deep reds go first. Timber looks flat. Skin looks slightly grey. Nobody can name the problem, but everybody feels it. Ra95+ with R9 above 50 fixes it. See the comparison.
3. It is uneven. Either the pocket is inconsistent, or a long run is being fed from one end and the far end has dropped off. Both are avoidable at planning stage and neither is fixable afterwards.
Strip placement
- Fix the strip to the inner face of the pocket, aimed up the wall or straight up, never out at the room.
- Set it back 30–45mm from the lip. Setback does more work than depth for hiding the source.
- Use an aluminium profile. Straighter line, better heat dissipation, longer life. The strip lives behind plaster — heat is the thing that kills it.
- Keep the throw path clear. Anything in the pocket casts a shadow band on the ceiling.
Continuous runs and corners
Cut only on the marked points — the KAYVA 480 Pro cuts every 50mm. At corners, either bend the strip around the profile's minimum radius or cut and rejoin with a connector. Never crease the tape; you will break the copper and the run dies at that point, sometimes months later.
Bench-test every continuous run before the ceiling closes. This takes ten minutes and it is the only chance you get.
Driver and voltage drop
Size the driver at load plus 20%: 12W/m × metres × 1.2. A 10m cove draws 120W and wants a 200W driver. Put it somewhere ventilated and accessible — not sealed above the plaster where nobody can ever reach it.
For runs over 6 metres, feed from both ends or split into segments. Otherwise the far end of the cove is visibly dimmer, and you will see it every evening for the next decade. Size it properly here.
Dimming
The driver dims, not the strip. Use a dimmable 24V constant-voltage driver with a trailing-edge (ELV) wall dimmer — leading-edge (TRIAC) dimmers commonly cause visible flicker on COB, and that is the complaint that comes back after handover.
If you want app or voice control, add a 24V CV controller — Tuya, Aqara, or any comparable brand. The strip is a passive load and does not care. Check the controller is rated for your total wattage.
The strip
The KAYVA 480 Pro Strip: 480 LED/m dotless COB, Ra95+ with R9 above 50, SDCM ≤5, 12W/m, 24V, 8mm PCB for standard channels, 20,000 hours at L70. Every batch tested, and the numbers published.