In garages, shops and warehouses, concrete floors are the busiest and the most overworked flooring surfaces. Day in and day out, concrete is subjected to enormous amount of strain from heavy vehicles, massive cabinets, metal power tools and bulky repair equipment. With all the pressure they endure, together with the temperature changes, concrete floors are prone to cracks and damages. To help in handling the load distribution of the floor and reduce the occurrence of cracking incidents, contraction and expansion joints come in handy.

What you need to know about expansion joints.

Perhaps you’ve wondered why concrete surfaces have gaps in them and why they are not just one big slab. The gaps in concrete are known as control joints or expansion and contraction joints and they are there for a substantial reason. These joints are placed in the slab as an allowance space for concrete expansion. Temperature changes make concrete expand and contract. The concrete expands into the floor joints, which relieves the pressure.

Expansion joints are the V-shaped grooves that are typically cut at every 5-10 meters at a depth of 5 mm and 5 mm wide. Having the floor joints in place helps create a weakened area in the concrete slab, since cracks follow the path of least resistance. The goal is to have the concrete crack inside a nice clean cut rather than cracking with random ‘spidery’ cracks throughout the floor.

Should Expansion Joints be filled?

Dealing with expansion joints is one of those tricky subjects in epoxy flooring. Some people will consider filling the joints before the epoxy coating is applied. It might sound like a good idea, but if the joints are filled with a solid material and then covered with epoxy, it defeats their purpose. Improperly filled expansion joints is where the chips and cracks in floors are born.

We do not fill the expansion joints; we paint epoxy over them to get the color continuity. We use 100% solids epoxy that is self-leveling and has a tough, flexible consistency and high elasticity. It goes over control joints, making the entire concrete floor strong and durable. As a result of our epoxy application, you’ll get a seamless finish with minimal chances of getting dents and cracks on the epoxy. Despite repeated expansion and contraction of underlying concrete, your epoxy flooring will stay strong, smooth and beautiful.

For more information on how we treat floor joints or to get our specific recommendations on extension joints in your floor, give us a call today!