Sill vs. Jamb — What's the Difference?

Designed to slope outward to prevent water ingress.

Supports the structural weight and facilitates operation.

The horizontal base component of a window or door frame.

The vertical side component of a window or door frame.

May feature decorative designs in certain architectures.

Can incorporate decorative elements in certain styles.

Often extends into the room, creating a ledge.

Houses elements like hinges or strike plates.

Can be made from various materials for durability.

Made from materials that offer strength and rigidity.

A horizontal member that bears the upright portion of a frame.

A jamb (from French jambe, "leg"), in architecture, is the side-post or lining of a doorway or other aperture. The jambs of a window outside the frame are called “reveals.” Small shafts to doors and windows with caps and bases are known as “jamb-shafts”; when in the inside arris of the jamb of a window they are sometimes called "scoinsons." A doorjamb, door jamb (also sometimes doorpost) is the vertical portion of the door frame onto which a door is secured.

A windowsill.

One of a pair of vertical posts or pieces that together form the sides of an opening, as for a door, window, or fireplace.

(Geology) A sheet of igneous rock formed by the intrusion of magma between existing strata.

A projecting mass or columnar part.

A breast wall; window breast; horizontal brink which forms the base of a window.

Either of the vertical components that form the side of an opening in a wall, such as that of a door frame, window frame, or fireplace.

(construction) A threshold; horizontal structural member of a building near ground level on a foundation or pilings, or lying on the ground, and bearing the upright portion of a frame; a sill plate.

(mining) Any thick mass of rock that prevents miners from following the lode or vein.

(geology) A stratum of rock, especially an intrusive layer of igneous rock lying parallel to surrounding strata.

Synonym of jambeau.

A threshold or brink across the bottom of a canal lock for the gates to shut against.

(transitive) To fix or attach a jamb to.

(anatomy) A raised area at the base of the nasal aperture in the skull.

The vertical side of any opening, as a door or fireplace; hence, less properly, any narrow vertical surface of wall, as the of a chimney-breast or of a pier, as distinguished from its face.

The inner edge of the bottom of an embrasure.

Any thick mass of rock which prevents miners from following the lode or vein.

(UK) A young herring.

See Jambes.

The shaft or thill of a carriage.

Upright consisting of a vertical side member of a door or window frame

Silly.

The basis or foundation of a thing; especially, a horizontal piece, as a timber, which forms the lower member of a frame, or supports a structure; as, the sills of a house, of a bridge, of a loom, and the like.

The shaft or thill of a carriage.

A young herring.

Structural member consisting of a continuous horizontal timber forming the lowest member of a framework or supporting structure

(geology) a flat (usually horizontal) mass of igneous rock between two layers of older sedimentary rock

A door jamb is the vertical component of a door frame, supporting the door, housing hardware like hinges, and contributing to the door's alignment and security.

Yes, a sill can be part of a door frame, referred to as a doorsill, providing a threshold and sealing the bottom of the doorway.

Sills are designed with a slope that directs water away from the window or door, preventing water from entering the building.

Yes, jambs are essential components of window and door frames, providing structural support and housing mechanisms for the operation of the window or door.

While they can be made from the same materials for consistency, the material of a sill can differ from that of the jamb based on functional and aesthetic requirements.

A windowsill is the horizontal base part of a window frame, often extending inside to form a ledge.

Precise measurements are taken of the opening width and height, ensuring the sill and jambs fit snugly and provide proper support and sealing.

An improperly installed sill can lead to water ingress, structural damage, and may affect the window's or door's functionality.

Like other building components, sills and jambs require maintenance to ensure their longevity and functionality, especially when exposed to harsh weather conditions.

Yes, both sills and jambs can be customized in terms of size, material, and design to match specific architectural needs and personal preferences.

Yes, especially in certain architectural styles, sills and jambs can feature decorative elements that contribute to the building's aesthetic.

Yes, damaged jambs can be repaired or replaced, though the process may vary in complexity depending on the structure and type of window or door.

Door jambs can house security features like strike plates and deadbolts, contributing to the overall security of the door.

Exterior sills are designed to repel water and are exposed to the elements, while interior sills may serve more decorative purposes and are not subject to weathering.

Sills and jambs work together to form the perimeter of a window or door frame, providing structural support, sealing against elements, and contributing to the aesthetic of the opening.