Understanding Joints in Concrete

Joints in concrete slabs are intentional breaks in the concrete which play a critical role in preventing cracking, as well as maintaining structural integrity and ensuring the longevity of a slab.^[1] There are several types of joints which play different roles in maintaining and protecting your concrete slab.

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Joints in concrete slabs are planned, intentional breaks created to control cracking otherwise caused by thermal expansion and other factors.

Installers form joints by placing a physical gap like a joint filler or sealant at specific intervals in the slab to minimize the potential for uncontrolled cracking.

Control joints provide a planned weakened area of the slab where the concrete can crack in a controlled manner. These are typically cut into the slab during the first 24 hours following placement.

Isolation joints are employed to prevent cracks caused by differntial movement.

Isolation joints are installed to isolate the slab from weight-bearing structures like walls or columns, or from legs of machinery which may vibrate, potentially causing damage to the slab.

Expansion joints are designed to allow for movement without causing stress to the slab and allow for the natural expansion and contraction of concrete due to temperature changes.

Construction joints are typically utilized to connect different sections of a slab that may be poured at different times, such as when pouring a large slab in sections.

Yes, jointless concrete slabs are possible with specific construction methods.These slabs forgo traditional joints and instead use reinforcement and special mix designs to help minimize cracking and allow for controlled movement. These slabs are typically more complex and expensive compared to those with traditional joints.

Yes, epoxy can be installed over your existing, jointed concrete floor. However, our installation experts will need to assess and properly treat those joints as part of the preparation process. Different types of joints will be treated differently depending on the purpose and the expected movement of that joint.

To learn more about installing resinous flooring over different materials, check our resource "Can Epoxy Flooring Be Installed Over Other Materials?"

Stonhard is committed to formulating the right floor, wall, and linings products for your environment along with expert installation to ensure your floor goes the distance. Contact us to learn how Stonhard can help you find the right solution for your facility.