June 18, 2025 Dean Horton

Are Roof Boxes Waterproof? What You Can (and Can’t) Pack Inside

If you’re loading up for a UK trip, you’re probably wondering:
"Are roof boxes waterproof?"
The short answer? Mostly — but there’s more to it than that.

Let’s break down how waterproof roof boxes really are, what you can safely store inside, and what to avoid (especially in typical British weather).

☔ 1. Are Roof Boxes Fully Waterproof?

Most modern roof boxes are made from moulded ABS plastic with:

Overlapping lids
Rubber weather seals
Integrated lock systems

✅ They’re water-resistant, not submersible
✅ Designed to keep out rain, spray & snow
⚠️ Not guaranteed airtight in extreme wind + driving rain

So yes — they’ll keep your stuff dry in 99% of UK conditions. But in a severe downpour or jetwash, a few drops might sneak in.

🧳 2. What’s Safe to Pack in a Roof Box?

Here’s what you can safely stash up top:

✅ Sleeping bags & duvets
✅ Foldable furniture
✅ Luggage in soft bags
✅ Well-sealed food or containers
✅ Dirty boots, wet towels (if boxed or bagged)

🔗 Read: How to Pack a Roof Box Efficiently

⚠️ 3. What Not to Pack (Even If It’s Dry Out)

🚫 Fragile electronics (laptops, tablets, cameras)
🚫 Paperwork or important documents
🚫 Anything temperature-sensitive (e.g. some medications)
🚫 Unsealed food (attracts moisture, smells, and pests)

Even if it feels sealed, temperature swings and condensation can damage sensitive items.

🧼 4. Add Extra Protection for Peace of Mind

If you’re worried about moisture, consider:

Packing gear in waterproof stuff sacks
Adding zip-lock bags for essentials
Lining the box with a thin tarp or picnic blanket
Throwing in a dehumidifier sachet or moisture absorber

✅ Pro tip: Pack valuables in the middle of the box, away from edges and seals.

🧪 5. Check the Seal Before Every Trip

Open your roof box and inspect:

Rubber weather seals — look for cracks or warping
Locking hinges — make sure they close cleanly
Latch tightness — not too loose, not over-tightened

🔗 Read: How to Fit a Roof Box Safely

🛠️ 6. Maintenance Tips to Keep It Weatherproof

✅ Clean the seals and lock areas every few months
✅ Store your box indoors or under cover when not in use
✅ Don’t pressure wash it (especially near the seams)

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