How a house is built
Layers of an outside wall
Cladding, a drainage gap, the weather barrier, sheathing, the stud cavity, and the interior board. One wall, several jobs.
Arrow keys turn the house. Plus and minus, or the zoom buttons, change the zoom. A horizontal drag turns it after you tap the drawing. Reset view returns to the step camera.
The drawing needs WebGL. The notes on the page still stand.
From the weather inward, this example shows cladding, a drainage gap, a water-resistive barrier, sheathing, insulated stud cavities, and interior board. The barrier and its flashings form the drainage plane. Sheathing may also brace the wall against sideways load.
Western Washington is marine climate zone 4C. Rain is the main wetting, and winter drying is slow. Whether the interior face uses a vapor retarder, and which class, depends on the whole assembly and the code edition. A sheet of plastic on the inside can trap water if the outside cannot dry. This section is the idea of the layers. It is not a wall specification for this house.