You need fire-rated downlights wherever the ceiling is part of the building's fire protection: typically a ceiling with a bedroom or other habitable room above it, a ceiling between flats, and an integral garage ceiling with rooms above. Each hole breaches that protection; a fire-rated fitting restores it with intumescent material that swells to seal the hole in a fire. Typical requirements are 30 minutes within a house and 60 minutes between flats. Under an unused loft in a bungalow they are usually not required, though many electricians fit them anyway.
A downlight is, structurally speaking, a hole in the ceiling with a light in it. Most people spend their time choosing the light. Building regulations care about the hole, because a plasterboard ceiling is doing a quiet second job, holding fire and smoke back from the rooms above for long enough to get everyone out. Cut six neat circles in it and, without the right fittings, you have made six small chimneys.
Why do downlights need to be fire-rated?
In most homes the ceiling between floors is part of the fire protection. Plasterboard on joists resists fire for a period, which slows a fire spreading upwards and protects the escape route for people upstairs. Downlight cut-outs are typically 60–80mm across (ours range from 58mm to 80mm), and each one goes straight through that layer. Hot gases and flame will find it quickly.
A fire-rated downlight closes the gap. Inside or around the body sits intumescent material, which expands rapidly when heated and seals the opening, restoring the ceiling's resistance for the period the fitting has been tested to, commonly 30, 60 or 90 minutes. The rating only holds if the fitting is installed as the manufacturer intends, in the specified cut-out size. An oversized, ragged hole undermines it.
Two points are often misunderstood. First, "fire-rated" describes what the fitting does for the ceiling, not the light itself: it is about keeping a fire below from getting through the hole, not about the lamp being less likely to start one. Second, the fitting's rating has to meet or exceed what the ceiling needs. A 90-minute fitting in a ceiling that needs 30 minutes is fine. A 30-minute fitting in a ceiling that needs 60 is not, however good it looks.
When do you need fire-rated downlights, and when not?
The principle in England's Approved Document B is that if a ceiling has to resist fire, anything that pierces it must not reduce that resistance. How much resistance a ceiling needs depends on the building, so treat the figures below as typical, not definitive. Your building control officer or electrician can confirm what your ceiling needs. Wales, Scotland and Northern Ireland have their own regulations.
| Ceiling | Fire-rated downlights? | Typical requirement |
|---|---|---|
| Ceiling with a bedroom or other habitable room above, in a house | Yes, usually | Commonly 30 minutes |
| Ceiling between flats, or with another home above | Yes | Commonly 60 minutes, more in taller buildings |
| Integral garage ceiling with rooms above | Yes | Commonly 30 minutes |
| Three-storey house or loft conversion | Yes, and the rules are stricter | Check with building control |
| Ceiling below an unheated, unused loft (a bungalow, for example) | Usually not required | Insulation and ventilation still matter |
That last row is the one exception people are pleased to hear about, and it comes with a caveat. Many electricians fit fire-rated downlights throughout as good practice, because fire-rated fittings are easy to find at everyday prices and the loft may not stay unconverted forever. At £15–£17 a fitting for the Valtari, we would do the same.
If you can't tell what a ceiling is protecting, assume it matters. Flat conversions, older houses with layered extensions and rooms over garages are where the answer is most often "yes" and the evidence least obvious. Ask the question before the first hole is cut, not after the plasterer has gone.
Valtari Slim · 90-minute fire rating, IP65
Fire-rated for 90 minutes and safe to cover with insulation. It needs a 68mm cut-out and only 32mm of depth, and comes in matt white, black, antique brass or polished brass.
Can you cover downlights with loft insulation?
Only if the manufacturer says so. Old halogen downlights ran hot enough that insulation had to be kept well clear, and that habit is still good sense for any fitting whose maker gives a clearance. LEDs run much cooler, but the LED and its driver still need to lose heat, and a buried fitting that isn't designed for it will run hotter and fail sooner. Look for a fitting described as insulation-coverable (sometimes marked IC). The Valtari's product data says it can be covered with insulation. Where a fitting needs clearance, a downlight cover (a hood fitted over it in the loft) keeps the insulation off.
There is a second reason to care about the top-floor ceiling. Every open downlight lets warm, moist air from the house into the cold loft, which wastes heat and can cause condensation on the timbers. A fitting with a sealed body closes that path. The same sealing helps between floors, where an open hole also carries sound. Some fire-rated downlights are separately tested for acoustic performance and airtightness. If either matters, between flats especially, check the spec for those ratings rather than assuming them.
Are plaster-in and bathroom downlights fire-rated?
They can be, and the Kanto range is. The Kanto trimless fittings described in our plaster-in downlights guide are fire-rated, and they plaster in flush so the ceiling shows only an aperture. If your ceiling needs a specific duration, 60 minutes between flats for example, ask us for the fitting's tested rating before you order.
| Fitting | Fire rating | IP | Cut-out | Depth | Light source | Price |
|---|---|---|---|---|---|---|
| Valtari Slim | 90 minutes | IP65 | 68mm | 32mm | Integrated LED, 600 lumens, dimmable | £15–£17 |
| Kanto Trimless (fixed) | Fire-rated: ask for duration | IP65 | 80mm | 106mm | GU10, 7W max | £17 |
| Kanto Mini Trimless | Fire-rated: ask for duration | IP20 | 58mm | 88mm | Kanto Mini LED module (sold separately) | £12–£14 |
Bathrooms add a second question: water. A downlight close to a bath or shower may fall inside a zone that needs at least IPX4, and even outside the zones, steam makes a sealed fitting sensible. Our bathroom zones guide shows where the lines fall. The Valtari and the standard Kanto are both IP65, so they meet it with room to spare. The Kanto Mini is IP20, so keep it outside the zones. Whether the bathroom ceiling also needs a fire rating depends, as everywhere, on what is above it.
Kanto Trimless · fire-rated, IP65, 80mm cut-out
Skimmed flush into the plasterboard, fire-rated and IP65, with a GU10 lampholder: our 3.7W Nimbus GU10 (£4, 3000K, CRI90) sits well within its 7W limit.
Who can fit fire-rated downlights?
A registered electrician. New downlight positions mean cutting holes, running new cable and connecting to the lighting circuit, which is not a job to learn on a ceiling that is holding back fire. In England, adding lights to an existing circuit in a living room or bedroom is generally not notifiable under Part P. A new circuit is, and so is work in the space around a bath or shower. A registered electrician self-certifies notifiable work, so you don't have to deal with building control yourself. Your electrician will also check joist positions (a cut-out has to fall between joists) and the depth of the void: 32mm is enough for a Valtari, while a Kanto needs 106mm.
If you already have downlights that aren't fire-rated in a ceiling that needs them, the usual fixes are to replace them with fire-rated fittings, checking the new cut-out matches the old hole, or to fit fire-rated covers over them from the loft side where there is access.
How many downlights do you need?
Fewer than you think, and in a fire-separating ceiling every one is a hole that has to be done properly. Place downlights over the places where work happens, not in a grid. Our plaster-in guide suggests four to six well-placed fittings for a typical 3×4m kitchen or bathroom, and a living room usually needs fewer still. For low rooms, our low-ceilings guide explains when recessed fittings are the right choice. The full range is in our downlights collection.
