Best Waterproof Junction Boxes for Outdoor Lighting: 2025 Expert Review
Oli
Owner, OR Electrics
If you have ever woken up to find your downstairs power tripped after a heavy night of rain, you arguably understand the importance of a good waterproof junction box. In Leeds, where the weather is famously unforgiving, water ingress in outdoor lighting is the number one cause of RCD tripping I attend to.
Many smart home lighting setups fail not because of the bulbs or the Wi-Fi connection, but because the connections are housed in cheap, brittle boxes that leak at the first sign of frost or heavy rain. Whether you are installing garden spike lights or extending a cable for a security camera, the junction box is your first line of defence.
In this review, I'll compare three specific junction boxes I've encountered: a reliable budget unit from a top brand, a high-quality IP68 multi-pack for extensive garden projects, and a clever inline connector that solves the problem of extending cables without bulk.
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Specs vs. The Real World
The Spec: "IP68 Rating Claims"
"The box is completely dust-tight and can be submerged in water permanently."
This is only true if the cable gland is tightened correctly around a significantly round cable. If you use standard flat Twin & Earth cable without a round flex converter or silicone sealant, water will track right down the cable and bypass the seal, regardless of the box's rating.
The Spec: "Tool-free Installation"
"Snap-fit connectors make installation instant and easy."
Whilst quicker, I always prefer screw terminals or lever connectors (like Wagos) inside a screw-down box for outdoor environments. Vibrations and temperature fluctuations (from -5°C to 20°C) can loosen poor connections over time, leading to arcing.
My Top 3 Recommendations
Three options to cover different needs and budgets
ABB IP44 Junction Box • Waterproof Electric Cable Connector Unit
ABB
ABB is a brand I trust implicitly in the industrial and commercial sector. This IP44 box is an absolute steal for surface-mounted applications where the box isn't likely to be submerged, such as under a porch or on a garage wall.
The Good
- Extremely affordable for a top-tier brand
- Self-extinguishing material enhances fire safety (UL 94 HB compliant)
- Easy snap-on lid with secure fastening
The Bad
- Only IP44 - cannot be buried or used in areas prone to pooling water
- Lower impact resistance compared to heavy-duty resin kits
Installer Tip:
Use this strictly for above-ground installations, perhaps for a motion sensor light on a brick wall. Ensure the cable entry points are at the bottom to create a natural drip loop, preventing water from running down the cable into the box.
Priced at £2.75 at the time of writing
Check Price on AmazonHIMOMO IP68 Waterproof Junction Box, 3-Way Outdoor Junction Box (4 Pack)
HIMOMO
When wiring up a series of garden bollard lights or daisy-chaining smart floodlights, you need reliability. This pack of 4 IP68 boxes offers a robust solution with high-quality seals that can actually handle being exposed to the harsh Leeds winter elements.
The Good
- True IP68 rating allows for underground installation (if correct cable used)
- 3-way design is perfect for daisy-chaining lights (In-Out-Light)
- Includes washers for various cable thicknesses (3-12mm)
The Bad
- Higher upfront cost (though you get 4 units)
- Slightly bulkier than inline connectors
Installer Tip:
The rubber ring sealing mechanism is excellent, but it relies on using round flexible cable (like Artic Flex or NYY-J). Do not try to jam standard flat grey electrical cable into these glands without appropriate adaptation, or you will compromise the waterproof seal immediately.
Priced at £19.99 at the time of writing
Check Price on AmazonElezenioc IP68 Waterproof Junction Box, 2-Way Outdoor Cable Connectors
Elezenioc
Sometimes you accidentally cut through a cable whilst gardening, or simply need to extend a lead for a new smart camera. This inline connector is the perfect problem solver. It's slim, rated 41A, and incredibly simple to fit without creating a massive junction box eyesore.
The Good
- Slim profile makes it easy to hide behind conduit or soil
- Impressive 41A rating means it can handle significant loads safely
- Comes with multiple rubber rings for different cable sizes
The Bad
- Only 2-way (straight through), so cannot be used to split power
- Screw terminals can be fiddly if you pass the cable through too far
Installer Tip:
This is my go-to for repairing accidental cable cuts on site. Because it supports up to 15mm diameter, it can handle armoured cable properly if stripped back correctly. Always tighten the gland nuts with a spanner, not just hand tight, to ensure the seal compresses fully.
Priced at £6.99 at the time of writing
Check Price on AmazonFrequently Asked Questions
What is the difference between IP44 and IP68 junction boxes?
Can I use flat Twin & Earth cable outside?
Why does my outdoor lighting keep tripping the RCD?
Do I need an electrician to install garden lighting?
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