Tents.... How to choose your tent .... What does H/H (hydostatic Head) mean?

One of the very first questions we are asked by customers who are choosing their very first tent is .... What does H/H ( Hydrostatic Head) mean in the tent descriptions? 
Modern Tents are made from polyester which unlike Canvas doesn't have any water repellency... Polyester has to be treated by the factories and then tested to give a waterproof rating ... Which is where the H/H figure comes from. 
H/H is the waterproof rating of the fabric used to manufacture your tent... a column of water is placed on the fabric - under tension and a measurement is taken at the level the water starts to penetrate the fabric - Hence the mm reading.... 
We have been selling tents for a number of years , when we started we had only ever camped in Canvas tents so polyester tents were a revolution to us but we soon learnt what to look for ....


For our family tents we like to see a H/H rating of at least 3000mm - some of our suppliers believe that anything beyond this is just a number... once the fabric has been treated to 3000mm there isn't much more protection beyond this. Others believe that the higher the better .... experience has taught us that as well as the waterproofing level it very often follows through that the quality and features of manufacture increase with the H/H - features such as mesh, vents and fly    screens..... 








Lower than 3000mm is fine for a weekend tent , festival tent etc this is still waterproof but we would probably suggest that you use your judgement to gauge the weather and if it's just a weekend then a torrential rain storm with heavy winds probably wouldn't be the best conditions. 












Specialist backpacking and Hiking Tents are very often treated to 5000mm H/H primarily due to the conditions that these tents are expected to cope with on a mountain side throughout the year. These tents are very often Ripstop Polyester too another feature that is making it's way into the Family Camping Market. 
















It's always worth remembering that a Tent is a temporary structure and you always need to be aware of the weather to make any necessary adjustments etc.....