What are control joints used for in masonry?

Control joints are used to relieve stress induced by small amounts of movement caused by shrinkage during curing or small expansion and contraction movements as the result of absorption and expulsion of moisture in concrete or masonry (brick, CMU, etc).

Where do control joints go in masonry walls?

In vertically reinforced masonry walls with masonry lintels, vertical control joints should be located between openings, or at least 24-inches away from the opening – not to exceed 25-feet on-center (Figure 1).

What are control joints in construction?

Contraction/Control Joints. Contraction/control joints are placed in concrete slabs to control random cracking. A fresh concrete mixture is a fluid, plastic mass that can be molded into virtually any shape, but as the material hardens there is a reduction in volume or shrinkage.

What is a control joint in brickwork?

Buildings and building components generally move slightly after construction. Control joints are vertical gaps, usually filled with in elastic materials, which allow brick veneer to respond to these movements usually by opening in response to expansion. …

How often do you need control joints in masonry walls?

A: When no joint reinforcing is used, National Concrete Masonry Association (NCMA) TEK 53, “Design of Concrete Masonry for Crack Control,” recommends spacing control joints in straight wall sections without openings no farther apart than twice the height of the wall, 40 feet maximum.

How many types of joints are there in construction?

The construction joint, control joint, expansion joint, settlement joint, and the seismic joint are some of the common types of joints in building construction. Building joints allow for movement along the depth of the structure.

What is difference between construction joint and expansion joint?

An expansion joint separates the building components above foundation such as walls, floors, roofs (except wooden roof) into several separate parts,so that the building can expansion or contraction in horizontal direction. The plane of separation between the placements is called a construction joint.

What types of movement joints are required in a concrete masonry wall?

What type of movement joints are required in a brick masonry wall and where are they installed? Expansion joints are required to control expansion of brick wall by temperature changes in both vertical and horizontal directions.

What is the purpose of a construction joint?

Joints allow one concrete element to move independently of other parts of the building or structure. Joints also let concrete shrink as it dries—preventing what’s called internal restraint. Internal restraint is created when one part of a slab shrinks more than another, or shrinks in a different direction.

What are Masonry movement joints?

Movement joints such as control joints are one method used to relieve horizontal tensile stresses due to shrinkage of the concrete masonry units, mortar, and when used, grout. They are essentially vertical planes of weakness built into the wall to reduce restraint and permit longitudinal movement due to anticipated shrinkage, and are located where stress concentrations may occur.

What is the purpose of joint reinforcement in masonry walls?

Continuous horizontal joint reinforcement is placed in the horizontal mortar joints of the masonry wall. It’s primary function is to minimize shrinkage, temperature, and settlement cracks in masonry but it also helps transfer shear load to the steel. Lastly, it is also used to tie inner and outer wythes together in cavity wall construction.

What is the spacing of concrete slab control joints?

CONTROL JOINT SPACING Space joints (in feet) no more than 2-3 times the slab thickness (in inches). A 4″ slab should have joints 8-12 feet apart.

What is a soft joint in masonry?

A soft joint, or control joint, is simply one grout line, all the way down the length of your installation, that is filled with colored silicone or caulk rather than grout . The purpose of a soft joint is to allow movement in your installation without cracking tiles or grout.