Knee Wall
Definition and meaning of Knee Wall in real estate.
Knee wall is a short vertical wall, typically under three feet in height, used to support roof rafters or block off the low space where a sloping roof meets the floor.
In more detail
In wood-frame construction, knee walls serve both structural and aesthetic purposes. Structurally, they reduce the span of the roof rafters by transferring the roof load down to the floor joists below. Aesthetically, they enclose the unusable, low-clearance areas under a sloped ceiling, creating a neat vertical wall surface.
These enclosed areas are often used for storage or run plumbing and electrical lines. Insulating knee walls properly is critical to prevent heat loss in attic living spaces.
Key facts
| Category | Property Types & Construction |
|---|---|
| Typical height | Typically less than three feet tall |
| Commonly found in | Attics, lofts, and story-and-a-half homes |
| Key function | Supports rafters and closes off low-clearance spaces |
During an attic renovation, workers build a thirty-inch-tall knee wall along the perimeter of the room to cover the tight corners where the roof rafters meet the floor, creating storage cabinets inside the wall.
Frequently asked questions
Are knee walls load-bearing?
Some knee walls are load-bearing because they support rafters, while others are purely partition walls built to enclose low attic spaces. Homeowners should consult an engineer before removing one.
How should a knee wall be insulated?
Contractors typically insulate either the knee wall itself and the floor behind it, or they insulate the roof rafters above the attic space to create a conditioned storage area.