Hidden lighting: plan it before the gypsum

Three layers of light

A well-lit room uses three layers of light, each with its own job, rather than one bright source in the middle of the ceiling.

• Ambient light: the even, general light of the room, usually from coves and downlights. It should be soft enough to sit under all evening.
• Task light: light aimed where you work or read, such as the kitchen worktop, a desk, the mirror or the bedside. Stronger than ambient light, and placed so it does not glare.
• Accent light: light that picks out a TV wall, a stone panel, a niche or a painting. It gives the room depth, and works when it is clearly brighter than its surroundings.

Put each layer on its own switch or dimmer, so the room can be bright for cleaning and soft in the evening.

Plan it before the gypsum: what is fixed at first fix

Hidden lighting cannot be moved once the gypsum board is up and painted, so its positions are settled at the electrical first fix, in this order:

1. Draw a lighting plan for each room

   Mark coves, profiles, downlights and accent lights on the ceiling drawings, with the furniture layout, so light lands where people sit, cook and read.

2. Group the circuits and switches

   Decide which lights switch together, which are dimmed, and from where: the door, the bed, the top and bottom of a stair. Each group needs its own cable run.

3. Fix driver positions and access

   Choose where every driver will sit and how it will be reached: an access hatch in the gypsum, a cupboard, or a cove that can be opened.

4. Build the gypsum around the lighting

   Cove depths, recesses for flush profiles and reinforcement for heavier fittings are built into the framing, not cut in afterwards.

5. Fit strips and fittings last

   Strips, diffusers and fittings go in after the final coat of paint, so sanding and spraying do not damage them.

Cove lighting or LED profile?

Both hide the LED strip, but the light is different. A cove is a trough in the gypsum that throws light onto the ceiling for a soft, indirect glow. A profile is an aluminium channel with a diffuser cover that shows a clean, direct line of light.

A clean line: no dots, no shadows

Dots, dark gaps and bright patches are the usual faults in hidden lighting, and almost all of them come from the detail rather than the strip:

• Match the strip to the detail. Closely spaced LEDs, or a continuous dotless (COB) strip, show far fewer dots, and every profile needs a diffuser set far enough from the strip.
• In a cove, set the strip back from the edge and some distance below the ceiling. Pressed close to the ceiling it makes a hard bright band; more distance gives a softer wash.
• Carry the light into the corners and join lengths end to end with no gaps, so there are no dark breaks.
• Feed long runs from more than one point, or use a 24-volt strip, so the far end is not dimmer than the start.
• Paint the inside of the cove matt white, so it reflects evenly.
• Make the ceiling flat before it is lit. Light grazing across a surface shows every wave and patch of filler.

Colour temperature and colour quality

Colour temperature, measured in kelvin (K), describes how warm or cool white light looks. In Egypt people simply say yellow or white; in practice there are three useful bands.

Keep one colour in each room, and buy each type of strip from one batch. Colour quality is a separate measure: the colour rendering index (CRI) shows how faithfully a light shows real colours, and 90 or more is a good target for a home. A poor strip can make marble look grey and wood look dull.

Dimming, control and drivers

Every LED strip runs from a driver that converts mains power to low voltage. The driver decides how the light dims and is a common source of faults, so choose and place it with care.

• Matched driver and dimmer: a mismatched pair causes flicker, buzzing, or lights that never switch fully off.
• Spare capacity and air: size each driver above the load of its strip, and never bury it in insulation or a sealed box, so it runs cooler and lasts longer.
• Access and labels: every driver needs a hatch, cupboard or opening cove close by, and a label naming the circuit it feeds. Keep a spare length of strip from the same batch for repairs.
• Phone and voice control: possible through smart drivers, wireless controllers or smart switches; many smart switches need a neutral wire in the switch box, so ask for it at first fix. A wired system such as KNX suits a large villa; a finished flat can go wireless without chasing walls.

Kitchens, stairs, bathrooms and outdoors

Each part of the home asks something different of hidden light.

• Kitchen: under-cabinet light in a diffused profile, fixed towards the front of the wall cabinet so your shadow does not fall on the worktop. Neutral white suits food preparation.
• Stairs: low-level step lights in the wall, or a strip under each nosing, make a stair safe at night without glare. Fix the positions before plaster or cladding, and consider a motion sensor.
• Bathrooms: fittings near the shower and basin must be rated for water and steam. A backlit mirror gives soft light, but a face is lit best from the front, not only from above.
• Outdoors: fittings and connectors made for outdoor use, with sealed joints and a suitable IP rating. On the North Coast choose housings and fixings that resist salt air, and aim uplights at palms and walls, not at the neighbours' windows.

How Itmam handles hidden lighting

Hidden lighting joins three trades: electrics, gypsum board and paint. Itmam does finishing, decoration and supply, so all three run as one job, and cove depths, driver hatches and switch positions are agreed with you before anything is built.

We visit, measure and give you a written, itemised quotation before work starts. On a finishing contract you pay each supplier directly and the tax invoice is in your name; our fee is for supervision and execution, agreed in writing before work begins. We work in Alexandria, the North Coast and New Cairo, and elsewhere in Egypt when the job suits.