Control Joints vs. Expansion Joints: What You Need to Know | Kaloutas

Fireproofing made easy. Call us today to discuss your needs.

Control Joints vs. Expansion Joints: What You Need to Know

Facility room under maintenance. Control Joints vs. Expansion Joints: What You Need to Know

When installing con­crete floor­ing, your con­trac­tors will like­ly sug­gest that you include joints, with con­trol joints and expan­sion joints being the most com­mon. It’s impor­tant for you to under­stand both kinds so you are pre­pared to fol­low your floor­ing contractor’s sug­ges­tions for your facil­i­ty. Learn­ing the dif­fer­ence between the two will also help you main­tain your expan­sion and con­trol joints in con­crete, keep­ing your facil­i­ty safe and functional. 

Con­ve­nient­ly, you no longer have to won­der, What is the dif­fer­ence between con­trol joint and expan­sion joint con­crete?” This guide has all of the rel­e­vant infor­ma­tion you need to know. 

Con­trol Joints vs. Expan­sion Joints

What Are Con­trol Joints: A Summary

A con­trol joint is the most com­mon type of joint you will see in con­crete floor­ing. These are designed to con­trol crack­ing as the floor cures. Installing and main­tain­ing con­crete con­trol joints helps pre­vent ran­dom cracks from form­ing in the floor over time, even after reg­u­lar use, shifts in the earth, tem­per­a­ture changes, and more.

What Are Expan­sion Joints: A Summary

Expan­sion joints are cut all the way through the depth of your con­crete slab. These joints are placed there to allow the con­crete to expand and con­tract with­out dam­ag­ing the floor­ing or its struc­tur­al integrity.

A Clos­er Look at Con­trol Joints

Con­trol joints in con­crete are some­times called con­trac­tion joints. These joints are cut into the con­crete while it is still fair­ly fresh. Most of the time, it will be cut with­in about six to 18 hours of a con­crete pour. While expan­sion joints are cut all the way through, con­trol joints only go about a quar­ter of the way through a slab.

These joints are designed to con­trol the crack­ing direc­tion as the con­crete slab shrinks over time. The goal is for most of the crack­ing to occur with­in these con­trol joints instead of the con­crete — this extends the dura­bil­i­ty of the floor while improv­ing its appearance.

Because you want any cracks or move­ment to occur in the joints, they are placed at the part of the floor with the high­est ten­sile stress. This includes spots in long walls or slabs, as well as abrupt changes in a cross-section.

A Clos­er Look at Expan­sion Joints

To bet­ter under­stand expan­sion joints, remem­ber that con­crete will form to the ground’s topog­ra­phy as it dries. But cer­tain parts of the con­crete will shrink more, caus­ing stress and pulling on oth­er areas of the slab. The expan­sion and con­trac­tion also occur with changes in tem­per­a­tures. Heavy loads can also cause extra stress on the floor, lead­ing to cracks.

As men­tioned, expan­sion joints are cut through­out the entire slab. They are then filled with a com­press­ible mate­r­i­al or filler. 

Includ­ing expan­sion joints in your con­crete lets the mate­r­i­al expand and con­tract with­out cre­at­ing ran­dom cracks. Essen­tial­ly, an expan­sion joint will iso­late var­i­ous parts of your slab, let­ting the entire slab move with­out caus­ing undue strain on any area.

The way that your floor­ing expert cuts expan­sion joints depends on the weath­er. In hot­ter weath­er, they typ­i­cal­ly use groov­ing tools while the ini­tial con­crete is still wet. But in cool­er areas, pro­fes­sion­als can cut them using a saw after some hard­en­ing has occurred.

To cal­cu­late the max­i­mum dis­tance between expan­sion joints, take the con­crete width in inch­es. Change the units to feet and mul­ti­ply them by two or three. If your con­crete slab is four inch­es thick, you need joints no more than eight to 12 feet apart.

You will find expan­sion joints in near­ly any type of con­crete floor­ing struc­ture. This includes side­walks, bridges, pave­ment, slabs, ships, build­ings, pip­ing sys­tems, rail­road tracks, and more.

Sum­ma­riz­ing the Differences

Based on the above infor­ma­tion, you’ll notice that con­trol and expan­sion joints have dif­fer­ent pur­pos­es and sizes. They are also installed at dif­fer­ent times. 

Con­trol joints are specif­i­cal­ly designed to pre­vent cracks from shrink­age as the slab dries, while expan­sion joints are there to pre­vent future cracks due to expan­sion and con­trac­tion. An expan­sion joint is cut through the entire con­crete slab. On the oth­er hand, con­trol joints only go about a quar­ter of the way through it.

Sum­ma­riz­ing the Similarities

Both types of joints are designed to pre­vent your con­crete floor­ing from form­ing cracks, although they do so in slight­ly dif­fer­ent ways and at slight­ly dif­fer­ent times. Both joint types are also notice­able if you look at the floor close­ly. As such, most con­trac­tors will do their best to either hide the joints (such as under walls) or make them dis­creet. If an area needs a lot of expan­sion joints, they may even be turned into an aes­thet­i­cal­ly pleas­ing pat­tern, such as a checkerboard. 

Oth­er Types of Joints

Keep in mind that expan­sion and con­trol joints are far from the only types you will see in con­crete floor­ing. There are also iso­la­tion joints and cold joints. Iso­la­tion joints sep­a­rate con­crete slabs from oth­er types of sur­faces, such as pipes, struc­tur­al beams, or walls. They are nec­es­sary because oth­er sur­faces move at dif­fer­ent rates than con­crete slabs. Cold joints refer to the seam cre­at­ed when you pour one slab and then pro­ceed to pour anoth­er next to it. 

The Impor­tance of Main­tain­ing Your Joints

Now that you under­stand the dif­fer­ence between con­trol joint and expan­sion joint con­crete, it’s time to con­sid­er main­te­nance. No mat­ter the type of joint you have in your con­crete, it will require reg­u­lar main­te­nance. Main­tain­ing con­crete con­trol joints is just as impor­tant as prop­er­ly fill­ing them with flex­i­ble joint mate­r­i­al dur­ing the instal­la­tion process. Make sure your cho­sen con­trac­tor uses the appro­pri­ate flex­i­ble joint mate­r­i­al dur­ing repairs as well.

A few poten­tial issues come with joints. If you don’t care for them prop­er­ly, debris and oth­er items can enter the joints. This could poten­tial­ly dam­age them or hurt their functionality. 

The oth­er issue with joints is that the edges can start spalling and break­ing away. This is espe­cial­ly com­mon in high-traf­fic areas.

Edges that spall or break away are a seri­ous trip­ping haz­ard, putting your team at a safe­ty risk. On top of that, it will cause the con­crete to dete­ri­o­rate. It can even dam­age your fork­lifts by increas­ing wear on them.

Joints Can Become Too Dam­aged for Sim­ple Repairs

If you notice any of these issues but don’t address them imme­di­ate­ly, you can run into even larg­er prob­lems. If the joint reach­es a cer­tain width, you won’t be able to fill it with flex­i­ble mate­r­i­al, as this would not be strong enough to sup­port a forklift.

In this case, you may need to chip out the entire sec­tion and rebuild it with mor­tar. Only then would you be able to install new, small­er, flex­i­ble joint fill. Because this process is more involved, it takes longer and costs more than reg­u­lar joint repairs. 

What Hap­pens Dur­ing Expan­sion Joint Repair?

As men­tioned, it is cru­cial to repair and main­tain expan­sion and con­trol joints. The process of repair­ing expan­sion joints typ­i­cal­ly starts with grind­ing uneven sur­faces to make them even. Then, the repair tech­ni­cians will clear debris. They will then place joint filler to make a lev­el sur­face. From there, the tech­ni­cians can cut a new joint into the repaired floor. Final­ly, they fill it with the flex­i­ble joint filler. 

Your floor­ing repair team can also replace or repair the epoxy coat­ing on sur­round­ing parts of the floor. 

Find a Reli­able Joint Main­te­nance and Repair Team

Kaloutas is proud to be New England’s pre­mier provider for con­trol joint repairs and main­te­nance. By spe­cial­iz­ing in repairs and main­te­nance, we can focus on per­fect­ing the best tech­niques and diag­nos­tics for your joints. Our exper­tise ensures dam­aged joints are addressed and don’t inter­fere with your busi­ness operations.

Let the experts at Kaloutas inspect, repair, and main­tain your facil­i­ty’s con­trol joints for stur­dier, safer floors. Con­tact us and get a quote today.

Partner with Kaloutas

Kaloutas simplifies facility management by offering comprehensive services including industrial flooring, cleaning, coating, fireproofing, and containment. We streamline your operations, ensuring compliance, safety, and aesthetics while reducing complexity in the process. Our Hard Work Made Easy solution eliminates the need for multiple contractors, guaranteeing minimal downtime and expert execution. With over 30 years of experience, we make facility maintenance effortless. Contact us to discover how we can meet your needs and save you time through our consolidated approach.

Partner With Kaloutas

Your facility's needs wait for no one. Fill out our form below and a sales team member will connect with you within 24 hours.