It rains a lot here, and I've not had issues with using whatever I bring in from the first floor. Except when we got 14 inches in one day. But it drained pretty quickly and dried out nicely once I added a little pine bedding, more forest litter, and mixed it all up.Not necessarily.
Some materials will pack, mat, and mold under certain circumstances, but if the area is well-drained, the layers aren't put in too thickly, and the chickens are encouraged to keep it turned and fluffed (toss treats into the area that needs work), they are usually fine.
A mix of materials can be less likely to pack and mat.