What are the layers of a pressurized fuselage (cross-section and construction)?
The pressure hull is the aluminum tube formed by the outer skin and supporting frames which serve to stiffen it.  Within that is a layer of insulation which is fibreglass in a ripstop plastic material envelope made into custom fitted sections clipped into place, then the facia panels that create the interior surfaces.  At max pressure differential the hull swells a little bit, maybe a quarter inch in a large airliner.  The primary structure is the outer tube.

A big problem with airliners is warm and very humid interior air (from the passengers) is able to circulate between the facia panels and outer hull and some of this air gets between the insulation batts and the outer skin, which at altitude is really cold so the moisture condenses as frost/drops.  Over time water starts to get absorbed into the insulation.  Airliners can have hundreds of pounds of water in the insulation especially down at the bottom, and at heavy checks the insulation has to be removed and dried out.