Ireland does not do half-measures when it comes to weather. From the Wicklow Way in a November squall to the Comeraghs in driving Atlantic rain, your outer layer needs to work as hard as you do. The difference between a jacket that holds up and one that lets you down comes down to two measurable standards: waterproof rating and breathability. The Trailpeak Waterproof Jacket is built around 10,000mm Ventron™ protection: waterproof, windproof and breathable, with sealed seams and a sealed front zip.
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What is a waterproof rating?
A waterproof rating measures a fabric's resistance to water penetration in millimetres: the height of a water column the material can hold back before moisture pushes through. A jacket rated at 10,000mm, like the 10,000mm Ventron™ membrane in the Trailpeak, withstands a 10-metre column of water pressure before the barrier is breached. It is a laboratory-measured figure, not a marketing line. For anyone spending serious time outdoors in Ireland, it tells you whether your gear is built for a brief urban shower or a full day of exposure on an open ridge in persistent heavy rain.
How is waterproof performance tested?
Waterproof ratings are determined using the Hydrostatic Head Test. A fabric sample is clamped beneath a sealed column of water, which is increased incrementally until penetration occurs. That measurement in millimetres becomes the jacket's official rating. The test measures fabric in isolation, so real-world performance also depends on seam sealing and zip construction. The Trailpeak Waterproof Jacket pairs its 10,000mm Ventron™ membrane with fully taped seams and a sealed front zip, closing off the stitching and zip points where most waterproof failures actually occur.
The waterproof rating scale
| Waterproof rating (mm) | Protection level | Best suited for | Typical example |
| 0 to 5,000 | Basic | Light drizzle, dry conditions | Packable emergency rain shells |
| 6,000 to 9,000 | Moderate | Casual use, short walks | Everyday and commuter jackets |
| 10,000 to 15,000 | Performance | Trail use, hillwalking, sustained rainfall | Trail shells like the Trailpeak (10,000mm Ventron™) |
| 16,000 to 20,000 | High performance | Mountaineering, winter conditions | GORE-TEX hillwalking hardshells |
| 20,000+ | Expedition grade | Extreme environments, alpine use | Alpine mountaineering hardshells |
At 10,000mm, the Ventron™ membrane sits at the entry point of genuine performance waterproofing, the right specification for the sustained, heavy rainfall that characterises Irish trail seasons. It is not over-engineered for conditions you will never face, nor does it cut corners for the ones you will.
Waterproof, water-resistant, water-repellent: the difference
These terms describe fundamentally different levels of protection and should never be used interchangeably. A waterproof jacket uses a sealed membrane, in the Trailpeak's case 10,000mm Ventron™ combined with fully taped seams, to prevent water penetration under sustained pressure. A water-resistant jacket relies on a DWR surface treatment that handles light rain but saturates and fails in heavy or prolonged exposure. A water-repellent finish causes droplets to bead on the surface: useful as a secondary defence, but not a standalone solution in serious conditions.
Breathability: why it matters as much as waterproofing
Breathability is a fabric's ability to let water vapour produced by your body during exertion escape outward, while maintaining its barrier against external water. Without it, perspiration condenses on the inner surface of the jacket, saturates your mid-layers and drops your core temperature, exactly the outcome a waterproof layer is supposed to prevent. The 10,000mm Ventron™ membrane in the Trailpeak Waterproof Jacket manages both at once: it blocks liquid water from outside while letting moisture vapour from perspiration pass outward, helped by underarm ventilation zips for higher-effort days. Breathability is measured using the Moisture Vapour Transmission Rate (MVTR), the grams of water vapour that can pass through one square metre of fabric per 24 hours. The higher the figure, the more effectively the jacket vents perspiration during high-output activity.
Choosing the right waterproof jacket for your activity
- Casual walking or urban use: a waterproof rating of 5,000 to 8,000mm handles light to moderate rain for low-intensity, short-duration outings.
- Hillwalking, trail running and day hiking: a minimum 10,000mm rating is the practical standard for Irish and UK conditions. The 10,000mm Ventron™ protection in the Trailpeak Waterproof Jacket delivers windproof, waterproof and breathable performance across the full range of conditions a serious trail user will meet.
- Winter mountaineering and multi-day expeditions: ratings of 20,000mm and above provide extra headroom for extreme pressure and prolonged exposure. For most trail users in Irish conditions, though, 10,000mm hits the ideal performance-to-practicality balance.
Frequently asked questions
How is the waterproof rating of a jacket determined?
The waterproof rating is measured using the Hydrostatic Head Test, where fabric is subjected to increasing water pressure until penetration occurs. The height of water in millimetres that the material can withstand becomes its waterproof rating, reflecting how well a jacket resists water under pressure.
What is the difference between waterproof, water-resistant and water-repellent jackets?
A waterproof jacket has a sealed membrane and taped seams to prevent water entry under sustained pressure. A water-resistant jacket uses a DWR finish that handles light rain but saturates in prolonged wet conditions. Water-repellent treatments cause water to bead up but are not enough for serious weather on their own.
Why is breathability important in a waterproof jacket?
Breathability lets moisture vapour from sweat escape outward, preventing condensation inside the jacket. Without it, perspiration builds up and soaks your inner layers, leaving you cold and uncomfortable. A breathable jacket keeps you dry from both rain and internal moisture during active use.
How do I choose the right waterproof jacket for my activity?
For casual walking or city use, a 5,000 to 8,000mm rating offers basic protection. For hillwalking and trail activities in Ireland, a 10,000mm rating balances waterproofing and practicality. For winter mountaineering or harsh conditions, look for jackets rated 20,000mm or higher.
Once you have the right shell, keep it performing with our guide to cleaning and reproofing a waterproof jacket, and if you only need wind protection, see our guide to windbreaker jackets.
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Order online for free Click & Collect, or free home delivery over €100 across Republic of Ireland and Northern Ireland, usually 1 to 2 working days with DPD.
Frequently asked questions
Can I collect orders in store?
Yes, choose Click & Collect at checkout. Orders are usually ready within 24 hours and you will get an email when ready. Available from our Dublin Carrickmines, Dublin Blanchardstown and Cork City Centre stores.
Do you offer free delivery on orders?
Yes, we offer free standard delivery on all orders over €100.
Where are your stores located?
We have four stores across Ireland: Dublin Carrickmines, Dublin Blanchardstown, Cork City Centre and Arnotts Dublin.