I must excuse my english. It's not my native language. Neither take this question too seriously. It's a stupid concept and I don't think that I will keep it by. It's just very "cool" to imagine a natural blanket over my world. (Please look at it as a challenge.)
Some insights, what the atmosphere I'm searching for shouldn't be able to kill:
There is not really a human like species on the world I'm "creating". Only in the oceans is some form of intelligent life. The landscape is dominated by roots. By wrapping themselves around each other they build some sort of streets through which they can steal/pass needed resources. Everything can handle pressure and a harsh atmosphere.
The system so far:
The planet is tidally locked in a short distance to a white dwarf. The planet is bigger than Earth and can hold a denser atmosphere. Five Moons keep the wind and the currents going. Through all the factors of friction created from the moons, the surface of the planet gets warm enough for life.
How I went searching a solution:
Being not very thick the layer/s of "frozen clouds" are able to float on the atmosphere. (What a start. Sorry xD)
There are pillars out of roots that go way up in the sky. They grow through the clouds and search for light gases. In that way they stabilize the clouds and hold them from breaking apart.
They are pretty high up where the gravity is less strong. (doesn't work well with the first idea, I guess)
Maybe the moons could help keeping the clouds up. (Sounds stupid, but with a dense atmosphere, there could be some kind of strong wind...)
(You see that I don't really have an idea what I'm talking about)
So... if... How is it possible to keep them in the sky?
. . .
Dear actually nice people on the internet:
Ok... I didn't expect this forum to be that active. - I'm exited. Thank you all for trying to help.
I'm sorry that I called the layers out of ice "ice clouds". (I didn't know how I should call them) I don't want my "clouds" to be like in interstellar. Ice is... heavy. Because of that I thought of much thinner layers that have a large surface. Some are heavier and float lower, others are thinner and float higher. There just should be a height zone where they are common.
I still don't exactly know how they are made. Maybe when specific proportions of gases get high up into a colder area, they eventually crystalize around some particles to... Sounds stupid, doesn't it?
I thought that the structure of the "roots" might stabilize the ice. That may be a way to make the "layers of ice" static. - "Roots" or "climbing plants" grow into the ice in order to gain concentrated gases. From there they would grow even wider...
Is that enough information? I fear that I don't know any more details myself. That was the reason I came here in the first place. If this isn't enough I'd be happy to write my question again in a less cancerous and more thought out way.