A joint that allows for dimensional changes of different parts of a structure due to shrinkage, expansion or other causes. Its purpose is to prevent development of high stresses to the structure.

Control joints are groove inserted into a concrete surface to control cracking. Essentially, this groove is an intentional, controlled crack placed in the concrete to preclude the concrete's cracking on its own, in an uncontrolled manner. By placing control joints in concrete before it cures, any stress the concrete will be subjected to subsequently will not produce haphazard cracks that will be a landscaping eyesore. With a trowel or jointer, the mason can cut an even control joint that will be aesthetically pleasing. Control joints can also be cut into existing concrete surfaces using a saw with a masonry blade attached.

(1) When installing a large span of wallboard, a space is filled with a preformed metal piece, which permits expansion and contraction. (2) Masonry wall groove constructed as a control for expansion cracking. (3) Any joint which is made between structural sections to allow for differential movement.

an intentionally weakened break in a concrete surface to allow for contraction stress

A raised, flashed assembly (typically a single- or double-wood member attached to a wood base plate) that is anchored to the roof deck. It is used to relieve thermal stresses in a roof system where an expansion joint is not required, or to separate large roof areas (sometimes between expansion joints), and may be used to facilitate installation of tapered insulation.

A designated separation in the plaster system that allows for movement caused by expansion or contraction of the system. The construction of the separation is accomplished by installation of manufactured devices for this application, or by fabrication procedures in the field using suitable materials.

A control joint controls or accommodates movement in the surface component of a roof.

Tooled, straight grooves made on concrete floors or structures to “control” where the concrete should crack (as a result of shrinkage).

Provision for the dimensional change of different parts of a structure due to shrinkage, expansion, temperature variation, or other causes so as to avoid the development of high stresses. (Expansion/Contraction Joint)

A tooled or cut groove in concrete structures to control cracking. The concrete will still crack - you are just controlling where it will crack.

a joint that acts to regulate the location and degree of cracking or separation resulting from the dimensional change of different elements within a structure

A continuous unbonded masonry joint to regulate the location and amount of separation resulting from the dimensional change of different parts of a structure so as to avoid the development of excessively high stresses.

Sawed or tooled groove in a concrete slab used to regulate the location of cracking.

A joint designed to accommodate movements in concrete caused by temperature changes, volume changes, and drying shrinkage. The joint forms a weakened plane designed to control where the concrete cracks, rather than having cracks in random locations.

A continuous unbonded masonry joint that is formed, sawed or tooled in a masonry structure to regulate the location and amount of cracking and separation resulting from dimensional changes of different parts of the structure, thereby avoiding the development of high stresses.