Hydrostatic head

[coloradoan]

Do hydrostatic head measurements factor into your purchase decisions? I know some shelters have very high HH ratings, upwards of 5000mm. I've often heard that 1200 or 1500mm is the minimum to be considered waterproof. But I recently saw a Eureka tent that had a hydrostatic head rating of 800mm. Now I know that Eureka isn't Hilleberg, but I never thought of them as cheapo walmart tents either - you could always count on them to keep you dry. But then I also know that HH decreases over time and that a used Big Agnes tent that started out at 1500mm could easily be well below 800.

Any real world experience with different hydrostatic head ratings?

 

[coloradoan]

Here is a response I got from Eureka:

"While waterproof ratings can be from 600mm to 5000mmm, it is often related to the type of fabric being coated. For example, taffeta fabrics which have smooth hand require far less coating than more coarse oxford fabrics. An exception is often made when it come to high altitude/expedition-type tents. But, waterproof coatings of 800mm are well-suited to almost any weather. I have personally owned and used a Timberline 2-person tent since 1976 in every season and weather conditions without any issues at all.

"One of the most important steps in tent care and use is to maintain good seals on the seams. Most modern tents are factory-sealed but, over time, the seam tape can separate. At that point, removal of the tape and application of a liquid or cream seam sealant to take it's place is strongly recommended."

 

[Brad@Argali]

Do hydrostatic head measurements factor into your purchase decisions? I know some shelters have very high HH ratings, upwards of 5000mm. I've often heard that 1200 or 1500mm is the minimum to be considered waterproof. But I recently saw a Eureka tent that had a hydrostatic head rating of 800mm. Now I know that Eureka isn't Hilleberg, but I never thought of them as cheapo walmart tents either - you could always count on them to keep you dry. But then I also know that HH decreases over time and that a used Big Agnes tent that started out at 1500mm could easily be well below 800.

Any real world experience with different hydrostatic head ratings?

There's a lot to unpack with coatings, fabrics and HH ratings. They can vary quite a bit in terms of quality depending on where the fabric is made. It also depends on what material is used to coat the fabric. There are a lot of great tents that use a 1000 or even 1200mm HH rating that will hold their HH rating for a long, long time. If you want to go deep on this topic I'd check out this article I wrote addressing fabrics, coatings and waterproofness: https://argalioutdoors.com/advice/tent-fabric-backpack-and-lightweight-tents.