When shopping for tents or outdoor gear, you’ve likely come across the term “Hydrostatic Head” (HH). But what does it mean, and how does it impact your choice of tent?
Hydrostatic Head is a measurement of how water-resistant a fabric is. It represents the height of a water column (in millimetres) that the material can hold before water begins to seep through. For example, a tent with a Hydrostatic Head of 3000mm can resist a water column 3000mm tall before leakage occurs. Simply put: the higher the Hydrostatic Head value, the more waterproof the fabric.
But does this mean a higher HH is always better? Not necessarily. This guide will explain how to determine the ideal Hydrostatic Head for your tent based on your camping needs.
What Is a Good Hydrostatic Head Rating for a Tent?
The UK’s unpredictable weather means that a tent with a Hydrostatic Head of at least 1500mm is essential for most camping trips.
- Light Rain: A Hydrostatic Head of 1000mm to 1500mm can suffice for light showers and occasional use in dry weather.
- Moderate Rain: For steady rainfall, aim for a rating of 1500mm to 3000mm to ensure you stay dry.
- Heavy Rain or Windy Conditions: A Hydrostatic Head of 3000mm to 5000mm is recommended for harsher conditions, especially during prolonged wet weather.
- Snow or Extreme Conditions: For camping in snowy climates or during extreme storms, look for a Hydrostatic Head of 5000mm or higher.
That said, if it rains too much for too long, its going to get in. We was camping a couple of years ago, took the kids to an indoor play centre came back to find puddles in our tent. This is an Outwell tent with a very high HH – but it was the sheer volume of rain. There was then no wind or sun to dry out the tent so when it rained the next morning, small puddles got in again.
Hydrostatic Head Isn’t the Only Factor
While a high Hydrostatic Head rating is important, it’s not the sole determinant of how waterproof your tent is. Other design features play a crucial role, such as:
- Seams and Zippers: Water often seeps through poorly sealed seams or unprotected zippers. Look for tents with sealed or taped seams and zipper covers.
- Tent Design: A tent with good structural integrity and a steep slope will shed water better than a flat or poorly designed tent, even with a lower HH rating.
- Additional Waterproof Coatings: Some tents include coatings that cause water to bead and roll off the fabric, enhancing water resistance.
For example, a tent with a 3000mm HH rating and well-sealed seams will likely outperform a tent with a 5000mm HH rating but poorly sealed entry points.
What About Groundsheets?
Groundsheets generally have higher Hydrostatic Head ratings than the tent walls, as they are in constant contact with wet or damp ground.
- A good groundsheet should have a Hydrostatic Head of 5000mm or more to prevent moisture from seeping into the tent.
- Look for thick, durable materials to withstand wear and tear caused by rocks, roots, and uneven ground.
Can You Increase Your Tent’s Hydrostatic Head?
Although you can’t increase a tent’s HH rating, you can improve its overall water resistance with these tips:
- Use Seam Sealers: Apply seam sealers to reinforce the stitching and prevent leaks.
- Add a Tarp: Placing a tarp over or under your tent provides an extra layer of protection against rain.
- Reapply Waterproof Coatings: Use a waterproof spray or coating to restore the water resistance of your tent fabric. A UV-resistant coating can also protect the fabric from sun damage.
Hydrostatic Head Recommendations for UK Weather
In the UK, where rain is a frequent companion to camping trips, it’s essential to choose a tent with the right HH rating for your needs:
- Summer Camping: A tent with 1500mm to 3000mm HH is sufficient for most summer weekends, even with light to moderate rain.
- All-Weather Use: For year-round camping, opt for a tent with 3000mm to 5000mm HH to handle heavy rain and wind.
- Expedition or Extreme Conditions: For snow and severe weather, choose a tent with 5000mm to 10,000mm HH.
At Lexrope, we stock tents designed for the UK’s unique conditions, including options for all seasons. For example:
- Outwell Sundale Tent (6000mm HH): A robust choice for rainy UK summers, though no tent can withstand extreme downpours like a caravan roof!
- Laser Compact All Season 2 Tent (10,000mm HH): Perfect for expedition camping and extreme conditions.
Hydrostatic Head Ratings Abroad
Planning to camp outside the UK? Consider the weather conditions of your destination:
- Dry, Arid Regions (e.g., Australia): A tent with 1000mm to 2000mm HH is sufficient.
- Rainy Climates (e.g., Nordic Countries): Opt for 3000mm to 5000mm HH to handle heavy rain.
- Snowy Alpine Regions: Tents with 5000mm HH or more are ideal.
Finding the Best Hydrostatic Head for Your Tent
Hydrostatic Head is a key factor in choosing a waterproof tent, but it’s just one part of the equation. Design, seams, coatings, and materials all contribute to keeping you dry.
At Lexrope, we specialise in family-friendly tents designed for the UK’s weather. Whether you’re heading out for a summer weekend or tackling harsher conditions, we’ve got you covered. Explore our wide range of tents and find the perfect fit for your next adventure!