Fiber Mesh Concrete vs. Rebar: Which Is Better?
Come to a concrete decision on what type of reinforcement is best
Fiber concrete has better tensile strength, making it less likely to crack.
Rebar reinforcement is a more challenging option to install for DIYers, but it's a more affordable reinforcement technique.
Fiber mesh concrete has more flex, making it more suitable for slabs in climates that see freezing temperatures and excess soil movement.
Concrete is an incredibly durable building material when it has some type of reinforcement for added strength and longevity. The two primary options for strengthened concrete are fiber mesh concrete and rebar-reinforced concrete. In this guide, we’ll explain the differences between fiber concrete and rebar-reinforced concrete to help you decide which is the best and most valuable option for your next concrete project.
Fiber Concrete vs. Rebar: Key Differences
Fiber concrete is reinforced with small strips of carbon fiber that your concrete professional mixes directly into the concrete before pouring. This creates more uniform support and reinforcement throughout the concrete, reducing the risk of cracking and uneven settlement. Rebar-reinforced concrete has a grid of steel rebar running through the middle of the slab. Rebar-reinforced concrete is less flexible and more prone to cracking, but it’s more affordable and widely available.
What Is Fiber Mesh Concrete?
Fiber mesh concrete has small pieces of carbon fiber mixed directly into it. When the concrete cures around the fibers, they create a web of reinforcement that adds tensile strength to the slab and helps reduce the risk of cracking on the surface.
| Pros | Cons |
|---|---|
| Less likely to crack | More expensive |
| Tensile strength | Harder to DIY |
| More flexible | Limited availability |
| Ideal for thin slabs |
Best for:
Non-foundation slabs, like patios and driveways
Slabs in colder climates, where greater flexibility improves lifespan
Areas with clayey soil that expands and contracts with moisture changes
Pros of Fiber Mesh Concrete
The carbon fiber strips in fiber mesh concrete hold the slab together better and with more uniformity than steel rebar, which makes fiber mesh slabs less likely to crack on the surface. Two advantages of concrete with embedded fiber are increased slab lifespan and less need for concrete repairs and resurfacing.
Carbon fiber is more flexible than steel, so fiber mesh concrete can flex more than rebar-reinforced concrete. This makes it a better option in areas that see a lot of ground movement, whether from frost heave through your sand or gravel sub-base in colder climates or contraction and expansion where there’s a high concentration of clay in the soil.
Finally, rebar is really only a suitable option if your slab is more than 3 inches thick. For projects like concrete countertops, concrete dining tables, and some walkways and sidewalks, fiber mesh concrete is a better option and allows for thinner slabs with similar strength.
Cons of Fiber Mesh Concrete
Fiber mesh concrete is more expensive than rebar-reinforced concrete, in part because it’s a newer reinforcement option. Fewer companies offer fiber mesh concrete, so you’re less likely to be able to find a contractor that offers it, and you’ll spend more on the installation once you do find a professional.
Mixing carbon fiber uniformly into concrete requires access to a concrete mixer, so it’s a more challenging project to DIY.
What Is Rebar-Reinforced Concrete?
Rebar-reinforced concrete has a mesh of steel rebar running through the middle of it. The steel bars provide tensile strength to the concrete, making it less likely to crack. However, since the rebar forms a grid in the middle of the slab and isn’t distributed throughout, the concrete has less tensile strength and is more likely to crack, especially under heavy loads.
| Pros | Cons |
|---|---|
| More affordable | Tensile strength |
| Widely available | More likely to crack |
| Easier to DIY | Low flexibility |
| Support | Thick slabs only |
Best for:
Home foundations
DIY concrete applications
Areas that see minimal soil movement
Pros of Rebar-Reinforced Concrete
Rebar reinforcement has been the go-to option for strengthening concrete for over a century, and for good reason: it can support more weight. Not only is it the tried and true method, but virtually every concrete professional will be familiar and comfortable with it, making it more widely available and affordable.
If you’re DIYing your concrete project, rebar reinforcement is the way to go. You’ll still need to make sure you install the rebar properly, but you can get away without a commercial concrete mixer, making it an easier project to tackle yourself.
Cons of Rebar-Reinforced Concrete
Rebar-reinforced concrete is durable and strong, but it’s more likely to crack under heavy loads because of its lower tensile strength. As a result, you’ll need concrete repairs and maintenance more often.
Steel rebar has no flexibility, so your concrete slab won’t either. This also means an increased risk of cracking, especially if you live in an area that sees extreme temperature fluctuations or where expansive soil is an issue.
Finally, rebar reinforcement isn’t always possible for thinner slabs, so projects like concrete countertops or concrete pavers may not work with rebar. You could opt for diamond mesh as an alternative, but this provides less strength than rebar.
Fiber Concrete vs. Rebar-Reinforced Concrete
When you’re deciding which type of concrete reinforcement will work best for you, make sure you consider the following factors.
Appearance: Rebar-Reinforced
Rebar-reinforced concrete has a grid of rebar running through the middle, so you won’t have any reinforcement material visible on the surface. Fiber mesh concrete will have visible fibers on the surface, which makes for a less appealing appearance.
Options and Customization: Rebar-Reinforced
Those visible fibers on the surface of fiber mesh concrete allow fewer customization options, too. You can stamp rebar-reinforced concrete, polish it, add a salt finish, and much more that just isn’t viable with fiber mesh concrete.
Durability: Fiber Mesh
Carbon fiber is more flexible than steel rebar, and the fibers sit uniformly throughout your slab. As a result, your concrete will have greater tensile strength, will be able to resist soil movement better, and will be less likely to crack, requiring fewer repairs in the long run.
Price: Rebar-Reinforced
Rebar reinforcement costs less and is more widely available, so you’ll have less trouble hiring a concrete contractor that offers this option.
Ease of Installation/DIYability: Tie
Fiber mesh concrete is technically easier to install. Since the fibers are mixed throughout the concrete, you don’t have to worry about keeping your rebar grid in the center of the slab while you pour. However, rebar-reinforced concrete is easier to DIY because you don’t need access to a commercial mixer to get a uniform distribution of fibers.
Ease of Repair: Tie
Both fiber concrete and rebar-reinforced concrete are relatively easy to repair, and the concrete repair costs will be similar.
Frequently Asked Questions
Yes, fiber concrete can crack, and contrary to popular belief, it will crack under similar forces to rebar-reinforced concrete. The difference is in how the crack spreads through the slab. When you exert pressure on a slab, the slab flexes downward, putting tensile forces on the bottom of the slab. In rebar concrete, a crack at the bottom will also quickly appear on the top surface. In fiber concrete, the fibers hold the two sides of that bottom crack together, making it less likely for the crack to form on the top surface.
Fiber concrete can be a good option for a residential driveway that will hold up standard passenger cars. The fibers provide increased flexion over a rebar-reinforced concrete driveway, so you’re less likely to see surface cracks. For driveways that need to hold commercial vehicles or multiple vehicles, rebar reinforcement is a better option. Ask a concrete driveway company near you which is the best option for your situation.
