Joist vs. Truss — What's the Difference?

Often made from wood, steel, or concrete.

A framework of beams, typically forming triangles.

A horizontal member that supports floors or ceilings.

Provides support primarily for roofing structures.

Structural element evenly distributing weight overhead.

Often prefabricated and then assembled on-site.

Spans between walls or beams in buildings.

Composed of straight members connected at nodes.

Integral to a building's structural framework.

A truss is an assembly of beams or other elements that creates a rigid structure.In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assemblage as a whole behaves as a single object". A "two-force member" is a structural component where force is applied to only two points.

A joist is a horizontal structural member used in framing to span an open space, often between beams that subsequently transfer loads to vertical members. When incorporated into a floor framing system, joists serve to provide stiffness to the subfloor sheathing, allowing it to function as a horizontal diaphragm.

(Medicine) A supportive device, usually a pad with a belt, worn to prevent enlargement of a hernia or the return of a reduced hernia.

Any of the wood, steel, or concrete beams set parallel from wall to wall or across or abutting girders to support a floor or ceiling.

A rigid framework, as of wooden beams or metal bars, designed to support a structure, such as a roof.

To construct with joists.

An architectural bracket.

A piece of timber or steel laid horizontally, or nearly so, to which the planks of the floor, or the laths or furring strips of a ceiling, are nailed.

Something gathered into a bundle; a pack.

(transitive) To fit or furnish with joists.

(Nautical) An iron fitting by which a lower yard is secured to a mast.

To fit or furnish with joists.

(Botany) A compact cluster of flowers at the end of a stalk.

Beam used to support floors or roofs

To tie up or bind tightly.

To bind or skewer the wings or legs of (a fowl) before cooking.

To support or brace with a truss.

A bandage and belt used to hold a hernia in place.

(architecture) A structure made up of one or more triangular units made from straight beams of wood or metal, which is used to support a structure as in a roof or bridge.

(architecture) A triangular bracket.

An old English farming measurement. One truss of straw equalled 36 pounds, a truss of old hay equalled 56 pounds, a truss of new hay equalled 60 pounds, and 36 trusses equalled one load.

(obsolete) A bundle; a package.

(historical) A padded jacket or dress worn under armour, to protect the body from the effects of friction.

(historical) Part of a woman's dress; a stomacher.

(botany) A tuft of flowers or cluster of fruits formed at the top of the main stem of certain plants.

(nautical) The rope or iron used to keep the centre of a yard to the mast.

(transitive) To tie up a bird before cooking it.

(transitive) To secure or bind with ropes.

(transitive) To support.

To take fast hold of; to seize and hold firmly; to pounce upon.

To strengthen or stiffen, as a beam or girder, by means of a brace or braces.

To execute by hanging; to hang; usually with up.

A bundle; a package; as, a truss of grass.

A padded jacket or dress worn under armor, to protect the body from the effects of friction; also, a part of a woman's dress; a stomacher.

A bandage or apparatus used in cases of hernia, to keep up the reduced parts and hinder further protrusion, and for other purposes.

A tuft of flowers formed at the top of the main stalk, or stem, of certain plants.

The rope or iron used to keep the center of a yard to the mast.

An assemblage of members of wood or metal, supported at two points, and arranged to transmit pressure vertically to those points, with the least possible strain across the length of any member. Architectural trusses when left visible, as in open timber roofs, often contain members not needed for construction, or are built with greater massiveness than is requisite, or are composed in unscientific ways in accordance with the exigencies of style.

To bind or pack close; to tie up tightly; to make into a truss.

To take fast hold of; to seize and hold firmly; to pounce upon.

To strengthen or stiffen, as a beam or girder, by means of a brace or braces.

To skewer; to make fast, as the wings of a fowl to the body in cooking it.

To execute by hanging; to hang; - usually with up.

(medicine) a bandage consisting of a pad and belt; worn to hold a hernia in place by pressure

A framework of beams forming a rigid structure (as a roof truss)

(architecture) a triangular bracket of brick or stone (usually of slight extent)

Tie the wings and legs of a bird before cooking it

Secure with or as if with ropes;

Support structurally;

Essential for spanning large distances without many supports.

A truss is a framework of beams forming triangles, while a joist is a horizontal member.

A joist provides support for floors and ceilings.

Nodes are the joints where truss members meet, distributing loads.

Triangles in trusses provide geometric stability and efficient load distribution.

While trusses are more common for roofing, joists can be used, especially in flat roofs.

No, trusses can be made of wood, steel, or a combination of materials.

Trusses can span longer distances without intermediate support due to their design.

Yes, joists can also be made from steel or concrete.

Joists are installed parallel to each other, spaced at regular intervals.