Best Concrete Mix With Fiber Additives for Crack Control
Concrete fiber additives can help improve crack control and toughness when blended into cement or mortar. The best choice depends on how much material you need and the project’s setting: the 20-pound Marsui option suits larger jobs, while the 1-pound UPTTHOW package is better for small projects. Kerty Store offers a larger chopped-fiber quantity, and Fabbay divides its material into four packs. These products use fiberglass fibers; confirm the appropriate mix procedure and dosage for your specific concrete application before use.
| Product | Best for | Fiber length | Package amount |
|---|---|---|---|
| Marsui Fiberglass | Larger jobs | 3/4 inch | 20 lb |
| Kerty Store Fiberglass | Outdoor or moisture-prone areas | 0.75 inch | 17.6 lb |
| UPTTHOW Fiberglass | Small projects | 19 mm option | 1 lb |
| Fabbay Fiberglass | Divided, multi-use supply | 3/4 inch | 8.8 lb |
| Concrete Fiberglass | General wall and floor reinforcement | 3/4 inch | 6.6 lb |
Marsui 20-Pound Fiberglass for Concrete
Best for: Larger concrete or mortar jobs that require a substantial supply of 3/4-inch fiber. The package includes two 10-pound portions, which may make it easier to handle the material in separate batches.
Marsui describes the fibers as a reinforcement material intended to increase cement density and help reduce penetration and small cracks. The listing also says the fibers form an interconnected network that can improve impact and earthquake resistance. These are product claims, not a substitute for structural design or other required reinforcement.
Limitation: The package is relatively large for a small repair, and the listing does not provide a specific dosage per batch.
Kerty Store 17.6-Pound Chopped Fiberglass
Best for: Buyers who want a larger quantity for projects such as patios, basements, garden areas, or walls. The 0.75-inch chopped strands are described as suitable for blending into cement or mortar.
The product listing highlights crack and shrinkage control, toughness, and water-resistance-related performance. It also describes the fibers as resistant to corrosion, acids, and alkalis. Its suggested mixing sequence is to blend the fibers with sand and cement first, then add water and stir thoroughly.
Limitation: A 17.6-pound package may be more material than a small repair requires. The listing does not give a project-specific mixing ratio.
UPTTHOW 1-Pound Fiberglass for Mortar
Best for: Small jobs or buyers who want to try a modest quantity before purchasing a larger package. The listing identifies 19 mm as an available length option and describes uses involving walls, gardens, ponds, and damp areas.
UPTTHOW says its fibers distribute through mortar to help inhibit fine cracks and increase toughness. The product description also claims that the filaments increase cement density and can help limit penetration. Fiber length and package-weight options are listed, so check the selected variant before ordering.
Limitation: This selection is only 1 pound, which may not be enough for a larger project. The product listing does not specify a dosage.
Fabbay Four-Pack Concrete Fiber Additive
Best for: Buyers who prefer several smaller packs rather than one large bag. The listing specifies four packs of about 2.2 pounds each, for a total of 8.8 pounds, with 3/4-inch (19 mm) fibers.
Fabbay positions the additive for decorative or reinforcement uses such as countertops and exterior walls. Its description says the fibers can improve mortar toughness, help avoid fine cracks, and reduce infiltration to some extent. It also suggests adding more for high-impact or severe freeze-thaw areas, but does not provide a numerical amount.
Limitation: The listing does not state a standard dosage, and its suggestion to use more in demanding conditions is not a substitute for project specifications.
6.6-Pound Concrete Fiberglass Reinforcement
Best for: General wall, floor, and garden projects where a mid-sized quantity of 3/4-inch fiberglass is appropriate. The product description says the fibers can be mixed into concrete or mortar with water.
The listing describes the additive as a way to help prevent cracking and improve toughness, impact resistance, impermeability, and frost resistance. It also states that the fibers are intended to disperse through the mixture. These claims can help guide product comparison, but actual results depend on mix design and installation.
Limitation: The listing does not provide a specific fiber-to-cement ratio, so confirm the correct amount for your mix before adding it.
Buying Guide: Choosing Concrete Mix With Fiber
How much fiber should you buy?
Match package size to the amount of concrete or mortar you plan to mix. The 1-pound UPTTHOW package is the smallest option here, while Marsui provides 20 pounds. Fabbay’s four-pack divides its 8.8-pound supply into smaller units. Package size alone does not determine how much to add to a batch; follow the product instructions and project specifications.
What fiber length should you choose?
Four listings specify fibers around 3/4 inch or 19 mm. UPTTHOW lists multiple length options, so confirm the selected variant. Fiber length is one factor in choosing an additive, but it does not establish suitability for every concrete mix or structural application.
Where will the concrete be used?
Consider whether the project is indoors, outdoors, or exposed to moisture or freeze-thaw conditions. Kerty Store and UPTTHOW specifically mention damp areas, while Fabbay mentions exterior walls and freeze-thaw conditions. Check the product instructions and local project requirements rather than relying on a general-purpose fiber additive alone.
How should fiber be mixed into concrete?
Follow the package directions for mixing order and dosage. Kerty Store suggests blending fibers with sand and cement before adding water, while the 6.6-pound product describes adding fibers to the mix and stirring evenly. Avoid guessing the quantity: none of these supplied product descriptions gives a universal dosage for every mix.
Frequently Asked Questions
Does fiberglass in concrete help prevent cracks?
These product listings describe their fibers as helping inhibit fine or shrinkage cracks and improving mortar toughness. They do not guarantee crack-free concrete; results depend on the mix, placement, curing, and project conditions.
Can concrete fiber replace rebar or structural reinforcement?
The supplied product information does not establish that these fibers replace rebar or other specified reinforcement. Follow the structural design and applicable project requirements.
Can I add fiberglass to mortar as well as concrete?
The listed products describe use in cement or mortar mixes. Check the selected product’s directions to confirm the appropriate application and mixing method.
Which option is best for a small repair?
UPTTHOW’s 1-pound package is the smallest listed option, making it the most suitable quantity to consider for a small project. Confirm that its selected fiber length fits your application.