Concrete is the most common building material, and for many good reasons. It’s versatile and easy to produce.
It’s also very sturdy and durable. However, concrete isn’t indestructible. It’s highly prone to cracks, spalling, pitting, water damage, and more.
If concrete degradation is an issue for you, this article should come in handy.
Today, I will talk about why concrete cracks appear, how to prevent them, and most importantly, how to fix them if they’re already there.
Whether you’re dealing with hairline or foundation cracks, there’s no reason to worry.
Later in the article, I included multiple great types of glue for fixing all types of concrete cracks.
Recommendation – Sikaflex Self Leveling Sealant is a waterproof sealant perfect for large-scale repairs. It uses an innovative technology that ensures you have the perfect self-level sealant after applying it. It also provides maximum protection against frost damage and efflorescence.
Concrete is the most widely used composite building material in the world.
It’s made of a few main components, including coarse aggregates (typically gravel), fine aggregates (sand or crushed rocks), and a hydraulic binder, most often cement.
Cement usually comes in powder form and needs to be mixed with water to kickstart the binding process.
When the water evaporates, the mixture’s moisture content drops. This is how concrete hardens.
But this is also the most common cause of cracks. If the mixture has a high moisture content, it will shrink significantly during the curing process.
As the material shrinks, the concrete is exposed to tension. It inevitably cracks when the tension becomes more powerful than the concrete itself.
These initial cracks are typically smaller than 1/8” in diameter and don’t pose a danger.
However, just because cracks aren’t structural, that doesn’t mean they couldn’t compromise the concrete’s integrity in other ways.
Apart from being unaesthetic, these cracks expose the concrete to potential water damage.
If water sneaks into these open surfaces and seeps deeper into the concrete, this will slowly weaken and degrade the material.
Whether we’re talking about concrete foundations, entry steps, or driveways, this issue needs immediate attention.
What Works to Fix Cracked Concrete
Depending on the damage’s extent, budget, and preferences, there are two main ways you can fix concrete cracks.
First, there’s epoxy filler. Then, you have cement crack filler. I also included a bonus option for small repairs that endures damage prevention.
So, let’s take a closer look at each of these methods.
Check out my guide on glues for concrete for more info.
Epoxy filler is one of the most popular methods for fixing cracked concrete.
This two-part polyurethane polymer requires mixing, but it has many great perks worth considering.
First, these adhesives are economical and highly versatile. They’re used for many concrete applications, bonding, sealing, and filling voids and cracks.
It can also be used as an admixture when preparing concrete cement if you want to create epoxy polymer-modified concrete.
Epoxy filler is efficient in all application conditions, including very low temperatures.
It cures very quickly, and it’s stronger than the concrete itself. Epoxy filler restores concrete’s integrity and strength, making it more powerful.
The added strength of epoxy filler will keep the concrete from shrinking and expanding when exposed to natural factors such as fluctuating temperatures.
This method is best for fixing hairline cracks, other non-structural cracks, as well as more severe cracks that threaten structural integrity.
However, the epoxy filler isn’t recommended if you have to work on many cracks or if you’re dealing with active cracks.
Epoxy filler is a great concrete crack filler.
Cement Crack Filler
Using cement crack filler is another popular method to fix cracks in concrete.
Cement crack fillers are very versatile because you can find various formulations for many applications.
Some have great capillary action and go deep into the problem areas, delivering a very tight bond.
Others are non-runny and perfect for vertical or overhead applications. Whatever you need, there’s something out there for you.
They’re also very easy to use because they often come in special recipients equipped with very thin dispensers.
Most such products are quick-setting, which makes them great if you have multiple areas to work on.
Cement crack fillers come in a variety of colors. You can choose whichever option best blends in with the surface you’re working on.
This way, you can get very strong and lost-lasting results and a subtle finish.
These products are suitable for many types of applications, both small and large. You can even find specially formulated fillers that are dry and flexible.
These will prevent tension and further damage due to the natural expansion and contraction of the concrete material.
It’s an ideal concrete crack filler.
(Bonus) Concrete Sealer
Concrete sealer isn’t going to fix cracks, but it’s the best and easiest way to prevent them!
This product will isolate the concrete from damaging factors such as water or harsh chemicals.
A concrete sealer can also protect the very narrow cracks that are too difficult to repair with cement filler.
Constant moisture absorption and evaporation won’t do concrete any good.
It could degrade the material and make it prone to breaking or cracking, especially if you’ve noticed minor damage.
Sealers are also great for protecting concrete against surface abrasion.
Sealed concrete isn’t only protected from cracking but also pitting and spalling. You should seal concrete right away before damage can occur.
However, it’s never too late! If you’ve recently fixed concrete cracks, it’s a good idea to add a protective layer of sealant to prevent recurring incidents.
You can choose between two types of sealers. There are penetrating sealers, which sink into porous concrete surfaces.
Then, there are film-forming sealers, which lay on top of the concrete.
Film-forming sealers don’t form as tight of a bond and will require more frequent reapplication, but overall, their performance doesn’t fall far behind penetrating sealers.
Whichever option you choose, concrete sealers are very quick and easy to apply.
Many also come in tinted varieties, so you can change the entire look of your concrete floors if desired.
Even non-tinted sealers have a nice shiny finish that makes concrete look as good as a varnished floor.
It’s a high-quality concrete crack filler.
Unsuitable glues for concrete crack filler include super glue, wood glue, spray adhesive, and most types of Gorilla Glue.
Best Glues for Cracks in Concrete
Here are my recommendations for the best glues for cracks in concrete.
1. Sikaflex Self Leveling Sealant
- Perfect for concrete crack repair
- Best concrete adhesive
- Great bonding agent
- Can fix even a hairline crack on concrete
- Not fully transparent
This Sikaflex sealant is perfect for all sorts of large and small caulking projects.
Depending on your application needs, you can choose between 10 and 29 fl oz tubes.
What’s especially great about this product is that it doesn’t require you to use any additional tools.
With just a caulking gun and this sealant, you can get a very quick and effective application.
This product can get into the deepest cracks without effort and has excellent adherence to concrete and cement; no prep is required.
It’s also self-leveling, so you’ll fill all gaps evenly and precisely.
This is a premium quality sealant with great performance. Thanks to its innovative formula, it has an accelerated curing capacity and a tack-free time of 1-2 hours.
It retains its elasticity throughout the caulking process and also once fully cured.
As a result, it’s a great option for fixing those cracks or lifting slabs that result from repeated freezing and thawing cycles.
When it comes to tension resistance, this product got you covered.
Use this sealant on sidewalk joins, driveways, garage floors, balconies, terraces, pavements, and virtually any horizontal concrete surface.
You can fix all sorts of cracks, even those up to 1.5 inches wide. Indoor or outdoor applications, it doesn’t matter.
This stuff has extreme resistance to all weather factors.
Once cured, it’s also water immersion and completely waterproof.
While the curing color is a sandstone gray, this sealant is also stainable, sandable, and can be painted with rubber, oil, or water-based paint.
This product also works as glue for pottery.
2. Dap Concrete Patch Interior and Exterior
- Ideal for concrete crack repair
- Good quality concrete adhesive
- Works on hardened concrete
- Can fix concrete driveway cracks
- Not completely transparent
If you need to work on horizontal and vertical surfaces, this product is suitable exactly for that.
Dap Concrete Patch works well for all masonry applications, including walls, steps, sidewalks, driveways, patios, and more!
Even better, this stuff is ready-mixed, so you don’t have to prepare anything.
You open the recipient and start applying. You must brush it on and build up the layers until you reach the desired coverage.
This concrete patch works best for fixing small breaks and cracks and spot-leveling concrete.
This product will fix the issue and create a nice, even finish, whether pitting or spalling.
Performance-wise, this product works equally well for both indoor and outdoor applications.
It has a quick and strong adherence to concrete and dries without shrinking.
Once fully cured, you’ll have a strong and durable finish, and the concrete will look as good as new.
This product is great for fixing shallow cracks and other simple concrete damage.
The 32 fl oz can have enough for even more extensive applications. You get a good quantity of a product, making it easier to buy in bulk.
3. Bluestar Flexible Concrete Crack Filler
- Good concrete glue
- Works on cracked concrete floor and concrete slab
- Can fix even a narrow crack
- Good for any kind of concrete repair
- Small bottle
Look no further if you’re looking for a quick, affordable, and easy fix for concrete cracks!
Bluestar Flexible Concrete Crack Filler meets all these requirements and more!
This product comes in an 18 oz tube, which will suffice for multiple repairs. It’s also extremely easy to use.
You don’t even need a caulking gun. All you have to do is cut the dispenser tip and squeeze the bottle.
Trace along the length of the crack and even the excess filler with a putty knife.
Because you don’t need any additional equipment or set-up before getting to work.
With this certain and accessible product, you’ll save time and money every time you have to perform masonry repairs.
With regards to performance, this filler doesn’t disappoint either. It can easily fill cracks up to 1 inch wide.
Once cured, it remains flexible and highly resistant to water, cold, and heat.
Its flexibility helps overcome the tension from repeated exposure to moisture, heat, and cold temperatures.
This concrete filler will move together with the concrete that shrinks and expands, preventing other future fissures and cracks.
Once cured, this cement filler acts partly like a sealant by keeping water out of the application areas.
The extreme resistance to damaging factors ensures that you’ll get long-lasting repairs.
Finally, you can choose between two colors because this cement filler comes in light gray and regular gray.
Bluestar Flexible Concrete Crack Filler is also perfect as glue for ceramic repair.
4. 10′ Fast Set Concrete Foundation Crack Repair Kit
- Great concrete crack filler
- Works on any concrete surface
- Creates a strong bond
- Needs to be applied fast as it’s super quick to set
This is perhaps the most comprehensive concrete repair kit for DIY applications.
It has everything you need for all types of concrete crack repairs.
With just one purchase, you’ll get two cartridges of Hydra Stop 300 polyurethane foam, two cartridges of Poxy Paste surface port and crack seal adhesive, a caulk gun, and regular injection ports, inside-corner injection ports, written instructions, and a how-to DVD with clear and concise explanations.
You can use this kit for fixing cracks up to 10 inches, as long as stopping water leaks.
These concrete fillers are so strong and durable that they’re suitable for all sorts of repairs, including those on foundation walls, retaining walls, tunnels, and sewer maintenance holes.
The low viscosity polyurethane filler can also get into very narrow hairline cracks.
This kit has no crack too narrow or too large to fix.
For concrete filler injection, the innovative polyurethane foam is much easier and more effective than regular epoxies.
That’s because the foam expands up to 30 times its original size upon contact with water.
It can thus fill even the deepest cracks where epoxies might not be able to reach.
The polyurethane foam remains stable and never shrinks throughout the curing process.
The Poxy Paste comes in handy for fixing surface ports, and you can also use it to cover and seal cracks before injection.
The polyurethane foam and the poxy paste are set very quickly and cured with record speed for a reduced repair time.
5. Rust-Oleum Wall-Surface-Repair-Products
- Can fill even large cracks
- Very versatile
- No odor
- Is runny – not suited for vertical surfaces
Rust-Oleum Wall-Surface-Repair-Products is a great solution for repairing cracks in concrete.
It can patch holes and cracks on the exterior of your home and not only. This adhesive is perfect for a multitude of applications!
It’s easy to use and works well for most cracks and holes in concrete, so you shouldn’t worry about its performance.
Most professionals recommend this adhesive, thanks to the permanence of its bond.
Once applied, the glue forms a tough bond that resists most external hazards.
One application is all you need to mend most cracks and holes in your concrete garage or basement.
If you need to finish the construction, then Rust-Oleum Wall-Surface-Repair-Products is the best glue for you!
However, this product isn’t very good for vertical surfaces. Thankfully, it cures very fast (approximately 8 hours after application).
It also has industrial-grade strength, which you can use for large-scale repairs and construction projects.
Most importantly, it’s easy to mix and emits a low odor, so you don’t need to wear a face mask while working with it.
However, I recommend wearing gloves and working in a well-ventilated room. The glue is still toxic if you’re not careful!
How to Fix Cracks in Concrete
I recommend using a high-strength sealant when trying to repair concrete cracks.
Once you inject the sealant into the crack, the cement-based filler should expand and harden into a strong bond that fills up the crack.
If you use it correctly, the filler will expand enough, so the crack is sealed tight for many years.
Professionals claim this method works best for sealing deep cracks in concrete without doing anything else.
A cement crack filler is all you need, and you’re golden. Here are the steps you can follow to do this right:
- Clean the dirt around the area before you inject the adhesive
- Plug all the large holes with wooden sticks or a towel
- Drill a hole at the center of the crack, and ensure that this is the only opening left. This should prevent any leakage from the concrete cracks and let the adhesive expand perfectly into the cracks.
- Insert the injection straw into the hole that you drilled. Then, it would help if you injected the glue until it reached the crack’s end.
If you follow all these steps, you should be done repairing any concrete crack before you even realize it.
The bond should last for a few years without any consequences.
I recommend Sikaflex Self-Leveling Sealant because it’s a super-strong, resistant, and waterproof sealant for concrete cracks!
It’s not difficult to repair concrete cracks as long as you know what you’re doing.
This article serves as the best guide for you. With Sikaflex Self-Leveling Sealant on hand, everything should work out by itself.