Insulating around heat sources

Having the right gaps between ceiling insulation and heat sources like recessed downlights, chimneys, flues or extractor fans is important for fire safety.

Safety gaps for heat source

Below are the required safety gaps you need - measured from the outer edge of the heat source to where the insulation starts.

Heat sourceSafety gap needed
Recessed downlights (Some modern downlights installed after mid-2012 may be insulated up to but not covered [CA135 and CA80 models] or insulated up to and covered [IC and IC-F models] with suitably rated insulation material) Follow the manufacturer’s instructions if available – otherwise leave 100 mm minimum gap
Downlight transformers No gap, but do not cover with insulation
Brick or concrete chimneys 50 mm
Metal chimneys or flues 50 mm

Unducted extractor fans (insulation can get  trapped in these, causing the motor to overheat)

200 mm

If you have loose-fill insulation, you should use permanently fixed collars made of fire-resistant materials. The collars should extend at least 75 mm above the insulation layer.

It's worth checking your insulation occasionally to see that it hasn't slumped towards a heat source.

Downlights and insulation performance

Safety gaps are necessary with many recessed downlights to prevent the risk of fire. But these gaps leave holes in your insulation, reducing its ability to hold in the heat. If you have standard recessed downlights that require a safety gap, it's worth considering alternatives.

Switch to modern downlight fittings that don't need a safety gap

Modern fittings can have suitably rated insulation fitted over them and could save you up to $20 per year in lighting costs. There are a few different options on the market so ask your supplier or manufacturer for more information. If you’re not sure of the type you need, check with a registered electrician.

Switch to non-recessed fittings

Replace your recessed downlights with surface-mounted or suspended light fittings that you can insulate over. It’s best to do this during renovations.

New Domestic Downlight Standards – Lighting Council website