Not Sure What Skylight You Have?

• Measure the ceiling opening where the diffuser sits — not the overall panel size.
• Measure width and length (or diameter for round diffusers)
  Confirm the shape (square, rectangular or round)
  A photo of the diffuser or ceiling opening helps ensure accuracy

For a step-by-step guide, see our Skylight Measuring Guide

Not sure? Use our Product Identifier form above and we’ll confirm the correct size for you.

Start by identifying which skylight component you are replacing. The most common parts that require replacement are the skylight dome on the roof or the skylight diffuser inside the ceiling. Once the part has been identified, measuring the skylight opening or panel size will help determine the correct replacement. Looking at the shape of the dome or diffuser and taking a few simple measurements will usually narrow down the correct skylight part.

Many residential skylights installed in Australian homes follow common sizes such as 300mm, 400mm, 455mm and 500mm. Among these, 455mm skylight diffusers are one of the most frequently encountered sizes, particularly in hallways, bathrooms and kitchens where skylights are commonly installed.

Yes. In many cases the skylight dome can be replaced without replacing the entire skylight unit. If the dome has become brittle, cracked or damaged by hail, replacing the dome is usually the quickest and most cost-effective repair. As long as the skylight frame and flashing are still in good condition, a replacement dome will restore the skylight’s weather protection and light entry.

Yes. The skylight diffuser can normally be replaced on its own without replacing the rest of the skylight. If the diffuser has become yellowed, brittle or cracked, installing a new diffuser can restore the appearance of the skylight and improve how light is distributed throughout the room.

Measure the base of the skylight dome where it sits on the skylight frame. For round domes measure the diameter across the centre, and for square or rectangular domes measure edge to edge across the base. The internal diameter of the dome base is often the most important measurement because it determines the size of the skylight opening the dome is designed to cover.

Remove the diffuser panel and measure the diameter for round diffusers or the edge-to-edge width for square diffusers. If the diffuser is damaged or missing, measuring the ceiling opening or skylight shaft size will usually provide a reliable guide to the correct replacement diffuser size.

If you are unsure which skylight part you need, the easiest solution is to send us a photo of your skylight along with any measurements you have taken. Photos of the dome, diffuser, ceiling frame or skylight shaft opening often reveal details that help confirm the correct replacement part before ordering.