Tent material

Tent makers go on about the hydrostatic head of tent material. Whats that all about ? Some American tents seam a lot lower than the ones made for the UK market. Is silicone nylon the best tent material on the market ?

Any tent material with a HH of 5000, should be enough, unless something touches material from inside. Then it won't matter how high or low HH is, water will pass through that point.

 SiNy is lighter and 'supposedly' more waterproof than other materials, but not as UV resistant as PU. So I've been told.

 I've not noticed any differance, apart from the weight advantage.

I'll have a bash at a reply too.

Basically hydrostatic head is a measurement of how waterproof a material is, something with a hydrostatic head of 5000 means the material can resist the pressure of a 5 meter high column of water before water would pass through. Waterproof material is generally accepted as anything over 1500 if memory serves me right.

I guess the less changeable weather in certain parts of the states allows one a longer forecast so the ability to carry a tent with a tiny HH. 

That's the short version, when someone with a longer explanation comes along maybe you should ask them about silnylon misting too.

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twiglegs is right hydrostatic head is a test of how much weight of water that the fabric can take before failure. You dont need a very high number but the higher the better in some ways as tend to mean it'll last longer, but the trade off is normally price and abit weight.

Is silicone nylon the best tent material on the market ? Yes-ish. To generalise It's stronger, lighter and doesn't absorb water into the weave compared PU coated but the user does need to seam-seal it. But there's lots of different tent fabrics out there including combos.

huskyman wrote (see)

Any tent material with a HH of 5000, should be enough, unless something touches material from inside. Then it won't matter how high or low HH is, water will pass through that point.

Are you talking about condensation or water leaking through the outter?

 btw it's other way round with UV.

To clarify misting - thats basically micro leaks through some of the lighter/less coated versions and seriously unclear how much of it is condensation.

Definetly huge differences in the silicone coated nylons being used. (by essentially everyone.).

HH does degrade with time of course - there's a massive emperical study of how that works out for cuben and some very light sil nylons on this backpackinglight forum thread: here. (and maybe other follow ups.).

A flysheet rated at  3000 HH or more is generally adequate but the groundsheet should be more, say 5000HH or more.  (I own a LC2 20111)  

huskyman wrote (see)

FT, I was refering to something touching fly from inside tent, not condensation