NoGaBiker

Hi Jesper

Just to clarify, flys are not at all breathable -- they are completely waterproof, not breathable. That's why they exist.

Double wall tents (tents with a fly) work on the principle that moisture vapor escapes through the permeable tent walls then hits the underside of the impermeable fly, where it stops rising, cools off and becomes liquid (condensation.) It then tries to fall back on you but finds itself thwarted by the presence of the tent wall, which is not sufficiently "waterproof" to stop rain, but will stop the little drips of condensation that fall back onto it. It generally does this, though, by means of the surface tension of the water drops causing them to slide right down the outside of the tent wall and land harmlessly on the grass.

So often, if you touch the tent walls from the inside you will disturb those drops, the tension is broken, and they bleed right through the tent wall fabric and onto your bag.

Don't know if the size of your hubba hubba is such that you're bumping it a lot more in the night than you used to or not, but that's a possibility.

(Another type tent is the single wall, which has no rain fly. It utilizes a waterproof/breathable fabric and works much like a goretex jacket -- vapor escapes but moisture can't get back through. I use one of these called the North Face Solo 1. It works great at altitude where it's cold and dry most of the time. I've not tried it in the southeast in summer, where the fabric would probably not be able to let enough moisture vapor out fast enough to keep the inside dry.)