How far apart should expansion joints be in concrete sidewalk?

Joints are commonly spaced at distances equal to 24 to 30 times the slab thickness. Joint spacing that is greater than 15 feet require the use of load transfer devices (dowels or diamond plates). Contraction joints may be tooled into the concrete surface at the time of placement.

Are expansion joints required in sidewalks?

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.

Are expansion joints needed in concrete?

Expansion joints are virtually never needed with interior slabs, because the concrete doesn’t expand that much—it never gets that hot. Expansion joints in concrete pavement are also seldom needed, since the contraction joints open enough (from drying shrinkage) to account for temperature expansion.

What is a sidewalk expansion joint?

Expansion joints are put in place before the concrete is poured. Expansion joints are used to allow the slab to move and not put stress on whatever it abuts. If your existing concrete driveway, sidewalk, or patio happens to crack over time, there are several things you can do to prolong the life of the pour.

How often should you put expansion joints in concrete?

How often should you put expansion joints 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.

How do expansion joints in a sidewalk keep the concrete from cracking?

Concrete expansion joints give the slabs just enough room to move which helps prevent cracks & buckling. Without these joints, even a little movement creates pressure and stress on the concrete. Eventually weak spots can crack or buckle.

Why do you put expansion joints in concrete?

A concrete expansion joint – or control joint – is a gap which allows the concrete to expand and contract as/when the temperature changes. It forms a break between the concrete and other parts of a structure to allow movement without causing stress, which can lead to cracking.

What do you use to fill concrete expansion joints?

Expansion joints must be sealed with a flexible sealant, like QUIKRETE® Self-Leveling Polyurethane Sealant or QUIKRETE® Non-Sag Polyurethane Sealant…or an expansion joint strip, to prevent water from penetrating the joint and deteriorating the sub-base.

How big can a concrete slab be without expansion joints?

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.

How do you install a concrete expansion joint?

How to Install Expansion Joints in Patterned Concrete Step 1 – Choose Installation Spots for Expansion Joints Step 2 – Create Marking Lines Step 3 – Cut Out the Lines Step 4 – Remove Cut Out Concrete Pieces Step 5 – Sweep and Clean Joint Seams Step 6 – Fill Expansion Joint Seams Step 7 – Smooth the Seams

How do you repair a concrete expansion joint?

Restoring Concrete Expansion Joints the Hard Way. One of the common ways to repair concrete expansion joints involves some basic tools and a lot of time. Use a scraping tool, like a 5-in-1, to scrape out the old concrete expansion joint filler. Vacuum out the concrete expansion joints.

What are the types of concrete joints?

Keyway Construction Joint. The keyway construction joint is probably the most complex construction joint. This joint requires the time to build or buy a wooden, plastic, or metallic keyway and install the material into your formwork.

What is a driveway expansion joint?

A driveway expansion joint, also known as an isolation joint, is a space put between adjoining sections of concrete to help control cracking. An expansion joint may also be placed between a driveway and adjacent concrete slabs, such as the foundation of a house or garage.