Outdoor lighting — what's weatherproof and what's actually just water-resistant.

Walk into any lighting store and the outdoor section is full of fittings labelled IP44, IP54, IP65, or IP66. The numbers are on every spec sheet and most products. What is less common is a clear explanation of what the numbers actually mean and, more importantly, which rating you actually need for which part of your property.

Get this right before you buy and the fitting will last. Get it wrong and you will be replacing it — or having us replace the damaged wiring behind it — within a couple of years.

What the IP rating system is

IP stands for Ingress Protection. The rating is defined by AS/NZS 60529, which mirrors the IEC 60529 international standard. Every IP rating has two digits:

• First digit: protection against solid particle ingress (dust, debris), rated 0–6
• Second digit: protection against liquid ingress (water), rated 0–9

So IP65 means: first digit 6 (completely dust-tight) and second digit 5 (protected against water jets from any direction). The two digits measure different things. A fitting can be fully dust-tight but only splash-resistant.

The four ratings you will see on residential outdoor fittings

IP44 — splash protected, not rain exposed

First digit 4: protected against solid objects greater than 1mm (wires, small screws, insects). Second digit 4: protected against water splashing from any direction.

IP44 is the minimum rating required for outdoor use under AS/NZS 3000. The key word is "splashing" — incidental contact with water from multiple directions, but not a direct stream and not sustained rain exposure. This rating is appropriate for:

• Covered outdoor areas where the fitting is under a roof or deep soffit and will not receive direct rain
• Internal bathroom spaces that see steam and humidity but not direct water contact (some IP44 fittings are rated for Zone 2 bathroom use for the same reason)

IP44 is not appropriate for any location where rain can hit the fitting directly — an exposed wall, a post, an open pergola without adequate shelter. Installers and homeowners frequently put IP44 fittings in locations where the fitting receives direct rainfall, and then wonder why the housing fills with water within the first winter.

IP54 — dust resistant, directional splash protected

First digit 5: dust resistant (not fully dust-tight — ingress is limited but not prevented entirely). Second digit 4: protected against water splashing from any direction.

The jump from IP44 to IP54 is dust resistance rather than better water protection. The water rating is identical. IP54 suits the same locations as IP44 but in dustier environments — a workshop exterior, a rural property, areas near unsealed roads or construction sites. For most residential eastern suburbs properties, the dust improvement over IP44 is academic.

IP65 — dust-tight, direct water jet resistant

First digit 6: completely dust-tight. No ingress of dust under any test conditions. Second digit 5: protected against water jets projected by a nozzle from any direction.

IP65 is where you get meaningful weather protection for fully exposed outdoor locations. "Water jet" means a 6.3mm nozzle at 12.5L/min from any direction for 15 minutes — significantly more aggressive than rain. This rating is appropriate for:

• Fittings on exposed exterior walls receiving direct rainfall
• Fittings on post tops and garden lighting poles
• Eave-mounted fittings on open structures without shelter
• Exposed pathway and driveway lighting

The majority of residential outdoor lighting in Melbourne — where the fitting is anywhere it might see direct rain — should be IP65 minimum.

IP66 — dust-tight, powerful water jet resistant

First digit 6: completely dust-tight. Second digit 6: protected against powerful water jets — 12.5mm nozzle at 100L/min from any direction for 3 minutes.

IP66 is used where the fitting may be subjected to high-pressure cleaning, heavy rain combined with wind, or flooding exposure. Residential applications include:

• Driveway and gate lighting that gets hosed down regularly
• Fittings in positions exposed to wind-driven rain (certain orientations and roof pitches create conditions that exceed what IP65 was tested for)
• Fittings at or near ground level in low-lying areas prone to surface water

For most suburban eastern suburbs properties — Doncaster, Templestowe, Nunawading, Blackburn — IP65 covers the majority of exposed outdoor locations. IP66 is worth specifying where you plan to hose the area down or where the fitting position sees heavy wind exposure.

Soffit mounting versus exposed post mounting

Where a fitting sits matters as much as its IP rating.

Soffit-mounted fittings (under eaves, under covered pergola roofs) are partially protected by the structure above them. Depending on the soffit depth and the direction of the worst weather, IP44 may be appropriate. As a general rule: if the fitting can see the sky at any angle, use IP65. If it genuinely cannot receive direct rainfall at any plausible rain angle, IP44 is technically adequate, though specifying IP65 costs little more and provides a margin.

Exposed post-mounted fittings (garden lights, driveway lights, fence-top fittings) receive rain from above and sometimes from the side in windy conditions. IP65 is the minimum. These fittings also tend to sit lower where lawn irrigation, garden hoses, and surface water are relevant. IP65 handles garden hose splash; IP66 handles direct hose-down.

Buried and in-ground fittings use a different part of the IP scale — IP67 or IP68 — which covers temporary or continuous submersion. These are appropriate for in-ground path lighting, underwater pond lights, and drainage channel fittings. IP65 is not rated for ground contact or submersion.

Underground cable requirements

Outdoor lighting requires wiring, and wiring run in the ground requires specific cable types and installation methods. This is frequently overlooked when homeowners or unlicensed operators do their own outdoor lighting work.

Under AS/NZS 3000, underground wiring must be:

• Run in conduit (rigid or flexible) at sufficient depth — generally 500mm below finished ground level in areas subject to mechanical damage (driveways, paths) and 300mm in areas not subject to disturbance
• Protected against mechanical damage where it transitions between underground and above ground (conduit rising from the ground to a post or wall-mounted fitting)
• The cable type suitable for the installation — standard TPS is not rated for direct burial; underground rated cable or conduit-protected TPS is required

Outdoor lighting circuit cables that are run without conduit and without underground-rated cable will degrade. Moisture ingress into the cable sheath, UV degradation where exposed, and mechanical damage from digging are common failure modes. Doing this correctly is straightforward; undoing it after the garden has been replanted is not.

RCD protection

All outdoor circuits must be RCD protected under the current version of AS/NZS 3000. This is not optional and it applies to every outdoor lighting circuit regardless of where the fitting sits or how sheltered it is.

An RCD (residual current device) trips within 30 milliseconds when it detects current flowing to earth — which is what happens when water enters a fitting or damaged wiring, or when a person contacts a live conductor. The RCD protection needs to be at the switchboard or in a weatherproof enclosure appropriate to the location.

If a sparky quotes you outdoor lighting without mentioning RCD protection, ask where it is. It should be specified and installed as part of the job.

Common mistakes

IP44 on an exposed wall. The most frequent issue we see. Fittings on exterior walls without deep eave protection receive direct rain. IP44 fills with water, corrodes internally, and either fails or creates an earth fault that trips the circuit.

No conduit on underground cable runs. Usually done to save time on a small job. The cable fails within a few years and digging it up is significantly more work than doing it correctly the first time.

Assuming all 'outdoor' fittings are equal. Retail stores stock outdoor fittings across the full IP range. The label says 'outdoor' on fittings rated IP44 and IP66. The difference matters.

Ignoring RCD protection. On older homes where the outdoor circuit was added before current standards required RCD protection, the circuit may not be protected. Adding new fittings to an old non-RCD circuit does not grandfather the protection requirement — the new installation work triggers compliance with current standards.

Selecting the right fitting for your application

The simple version: if the fitting will see direct rain or will be hosed down, use IP65 or IP66. If it sits under genuine cover and will only see humidity and incidental splash, IP44 is adequate but IP65 costs little more and you won't be back up the ladder after the first big storm.

Where the fitting goes on your property — soffit, wall, post, ground — determines both the IP rating and the cable installation method. Getting both right means fittings that last and a circuit that is safe.

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If you are planning outdoor lighting for your home and want the wiring done correctly from the start, have a look at our lighting installation service and get in touch. We can advise on fitting selection and specification as part of the quote.