Do concrete walls need expansion joints?

Concrete expands and contracts with changes in temperature and moisture. If not properly controlled, cracks can begin to appear. Placement of concrete control joints and expansion joints are crucial when designing and pouring concrete slabs and sidewalks.

Where are expansion joints located in a masonry wall?

Masons can typically reach about 2 ft (600 mm) around the corner from the face where they are working. An expansion joint should be placed within approximately 10 ft (3 m) of the corner in either wall, but not necessarily both.

What is expansion joint in walls?

An expansion joint, also known as a movement joint, is an assembly consisting of a separation in a wall and a flexible material such as a sealant or bond breaker. A long masonry wall will expand or contract over its height and length when heated or cooled by ambient temperatures.

How far apart should expansion joints be in concrete?

Usually, expansion joints should be no farther apart than 2 to 3 times (in feet) the total width of the concrete (in inches). So for a 4 inch thick concrete slab, expansion joints should be no more than 8 to 12 feet apart.

What is the difference between expansion joints and control joints?

In building materials, a control joint is used to control cracking while an expansion joint is designed to handle structural movement. A control joint can be formed during placement of the building material or cut after the material is placed.

What are expansion joints on concrete walls for?

Expansion joints are separations between adjoining parts of a structure to allow movement. Expansion joints also work as contraction joints and may have smooth dowels to maintain the plane of the wall.

What is the difference between control joint and expansion joint?

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

Movement joints are used to allow dimensional changes in masonry and to minimize random wall cracks and other distress. There are various types of movement joints in buildings: expansion joints, control joints, building expansion joints and construction joints.

How do you calculate expansion joints?

The total expansion change can be calculated as follows: Total expansion change in inches = (coefficient of thermal expansion) x (maximum temperature range) x (length of run in inches). Example: Total expansion change = (3.38 x 10-5 in./in./°F) x (120˚F) x (90ft x 12in./ft) = 4.38 in.

How long can a brick wall be without an expansion joint?

In general, experience suggests that movement joints in clay brickwork should be spaced at approximately 10 – 12 metres. PD 6697 states that in no case should joints exceed 15 metres and the spacing of the first joint from an internal or external angle should not exceed half of the general spacing.

Do walkways need expansion joints?

A.: According to several industry sources, expansion joints, even at 50-foot intervals, are not necessary for the sidewalk project. Long stretches of concrete do not require intermediate expansion joints.

What material is used for expansion joints in concrete?

ASPHALT EXPANSION JOINT is composed of a blend of asphalts, vegetable fibers, and mineral fillers formed under heat and pressure between two asphalt-saturated liners. It is waterproof, permanent, flexible, and self-sealing.

What causes an expansion joint to close down?

For example, when a structure heats up, the building materials from which it is built expand. This causes the “expansion joint” to close down, thereby compressing the joint system installed in the gap. The above is a wall expansion joint. This structural opening bisects not only the facade but the structural building elements as well.

How is waterproofing handled in an expansion joint?

Waterproofing is handled on the structural slab by a buried waterproofing membrane. The expansion joint bisects all of the building elements including the structural slab, membrane, and wear course (bricks).

When does the joint system need to expand?

Conversely, when the temperature drops, the materials cool causing the joint gap to open. This requires the joint system to expand to follow the joint movement. Expansion joint transitions are essential for ensuring a sealed, safe, and energy efficient building envelope.

How are retaining walls and flood walls designed?

Both geotechnical and structural aspects of wall design are included. Coordination between geotechnical engineers, structural engineers, and geologists in the design of retaining and flood walls is essential. 1-2 EM 1110-2-2502 29 Sep 89 CHAPTER 2 GENERAL DESIGN CONSIDERATIONS Section I. Types of Retaining Walls 2-1.