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Home » Concrete Expansion Joints: Use An Epoxy Filler!

Concrete Expansion Joints: Use An Epoxy Filler!

Protect your investments, long term.

Concrete expansion joints are an essential component to ensure that your concrete flooring installations stay strong through any test. Expansion joints protect against expansion, absorb movement, and more – essentially protecting your floors for years to come. But concrete expansion joints alone can’t protect against everything. That’s where epoxy resin can help.

So join us as we unpack all you need to know about concrete expansion joints. Find out why epoxy might just be a contractor’s (or DIY enthusiast’s) best friend!

Why Do I Need Concrete Expansion Joints?

Concrete expansion joints are the small gaps between concrete slabs that help to resist thermal expansion and contraction. They’re necessary for your concrete slabs to stay solid for years to come. Especially when paired with a reliable filler, like epoxy resin!

Concrete floors are considered to be the gold standard of stable and solid flooring, but they need to be flexible. A concrete floor without expansion joints will crack, or even fail, under the pressures of expansion and contraction. But, the expansion joints themselves introduce new issues. Water damage, grime buildup, and more. That’s where epoxy comes in.

Image showing the grinding of a large industrial floor, before sealing.

Epoxy Filler for Your Concrete Expansion Joints

Epoxy is widely regarded as one of the best flooring solutions on the market. Despite that, many people haven’t considered its utility for filling in concrete expansion joints – until now!

Filling concrete expansion joints is an essential step in ensuring the longevity of your concrete-based projects. Epoxy resin is the perfect material to fill joints; it’s not only durable, but it also bonds to most surfaces. Epoxy bonds especially well with concrete! Its water-resistance and durability make epoxy resin ideal for filling cracks in concrete.

It’s also easy to apply, you just need to squeegee, pour or trowel the resin right into the pre-cut joint. This epoxy bond quickly becomes rock solid, and helps to resist any water and debris infiltration in the future. Epoxy is the answer – it provides superior protection against any elements, and wear and tear, with minimal cost and effort.

How to Prepare the Joints for Epoxy Filler Application

Properly preparing concrete joints before filling them with epoxy is key for a successful and long-lasting filling result. The first step to filling concrete cracks with epoxy resin is making sure the joint surface & the gap itself is clean from dirt, debris, and water. If possible, use a vacuum cleaner or powerful stream of air to blow off the dust and dirt.

In addition, exposed aggregate should be etched in order for the epoxy to bond bette. We recommend using a delicate phosphoric acid-based solution to etch, as it does not cause unnecessary damage. With preparation like this, your filling application will be structurally sound with an aesthetically pleasing finish.

If you’re a concrete or epoxy contractor and you want to hone your skills, consider our Epoxy Classes certification program! We’ll guide you through everything you need to know, and our veteran installers will answer any question you might have.

Different Types of Epoxy Fillers for Concrete Expansion Joints

When it comes to concrete expansion joint filler solutions, traditional epoxy concrete repair is a popular and relatively economical option to consider. However, advancements in technology have made specialized types of epoxy, such as polyaspartic, viable alternatives to traditional epoxy.

Polyaspartic utilizes unique reactive chemistries that allow it to remain both low viscosity and adhere effectively with the concrete itself. This helps extend the life of the joint filler solution by creating a strong seal between the joints and effectively keeping out environmental debris and moisture. It also cures much quicker! Therefore, choosing one of the many specialized forms of epoxy joint filler could be your best bet. Figure out what you need for the job you have!


All in all, there is no doubt that concrete expansion joints are an integral part of any masonry work. They provide the necessary flexibility for concrete slabs and help protect them against the everyday stressors. Utilizing epoxy filler to fill your concrete expansion joints is certainly a viable option due to its range of benefits. With the right preparation and installation, not only can you benefit from a great looking joint, but also one that can withhold high pressure and last over time. So if you’re looking into protecting any concrete construction project, epoxy fillers should definitely be at the top of your list!

Need help on the job, or getting ready before a big project? Our veteran technicians are only a phone call away at (954) 287-3797! Stock up on the latest and greatest in flooring resources on the EpoxyETC online store at affordable rates!