Garage Concrete Floor Repair Kit — Cracks, Pits, Holes & Spalls
This kit pairs Roadware 10 Minute Concrete Mender with everything needed to permanently repair cracks, pits, holes, and spalls in concrete floors — and have the floor back in service the same day. The Mender is a two-part hybrid polyurethane that is nearly as thin as water (under 8 cps), so it penetrates deep into the crack and the surrounding concrete matrix rather than just bridging the surface. It cures in about 10 minutes at room temperature, is trafficable almost immediately, and will not pop out like a rigid epoxy because it never becomes brittle.
It works for a single garage-floor crack and it works at industrial scale: Roadware 10 Minute Concrete Mender has been used for full-depth crack repair in large commercial facilities, including a multi-level Amazon warehouse where thousands of linear feet of shrinkage cracks were repaired full-depth with no sawing and the floor returned to service immediately. The same product, the same kit, scales from one crack to an entire shop floor.
Free NextStar technical support — call 1-866-445-3984 .
What's in the Kit — Products Included for Every Repair Type 2 dual cartridges of Roadware 10 Minute Mender (repairs up to 40 linear ft of 1/8-inch crack with silica sand)
NX-300 manual dispensing tool (300/300-150)
5 ¼ x 24 element static mixers
2 retaining nuts — Euro Thread (white, 9 pitch)
4 cross-over restrictors
Safety goggles
3 pair rubber gloves
Printed instructions and step-by-step instructional flash drive
SDS documents and product data sheets
Manual dispenser instructions
You supply: a hand grinder with dust shroud, shop vacuum, small trowel, and clean dry silica sand to extend the Mender for wider cracks and spalls.
Which Crack Do You Have? — Cracks, Pits, Spalls and What Each Needs Matching the repair to the damage is the whole job. 10 Minute Mender handles the full range below — the difference is how you mix and apply it.
Damage
How to repair it
Ultra-fine hairline cracks (under 0.5 mm)
Inject Mender directly — it is thin enough to wick in with no sand
Small cracks (0.5 to 2 mm)
Wet the crack with Mender, then add sand and trowel, repeating as needed
Wider cracks (2 to 15 mm)
Place dry sand in the crack first, flood with Mender, repeat in layers
Large cracks and holes (15 mm+)
Mix Mender with 2 parts sand and trowel into the repair area
Spalls and surface breakouts
Repair as a large crack, then grind flush with a diamond cup wheel
Delamination and voids
Drill into the void (not through the slab) and inject Mender directly, no sand
When to call a pro instead: if a crack is wider than 1/4 inch and still growing, if one side of the crack sits higher than the other, or if cracks are spreading across the slab, the floor may have a support or settlement problem underneath that a surface repair will not fix. Those signs warrant an assessment — call 1-866-445-3984 and we will help you tell the difference.
Same-Day Repair — Trafficable in 10 Minutes The reason this kit exists is speed without sacrificing strength. At about 72°F, 10 Minute Mender gels in 6 to 7 minutes and cures hard enough to grind, coat, or drive on in roughly 10 minutes — not the 24 hours a typical patch or epoxy needs before it takes traffic. For a working garage, a busy shop, or a warehouse that cannot shut down, that is the difference between a repair you schedule around and one you simply do.
Because the cured Mender bonds through the full depth of the crack and restores load transfer across it, the repair carries vehicle and forklift traffic rather than just sealing the surface. It also cures in cold conditions — down to well below freezing for the standard version — so freezer floors and unheated shops are in range. The low-odour LO version cures with no appreciable smell, which is what makes it usable in occupied buildings, food-storage areas, and enclosed spaces where a solvent odour would shut the room down.
Garage, Shop & Warehouse Floors — From One Crack to Thousands of Feet Garage floors. Seasonal temperature swings and the weight of vehicles open shrinkage and settlement cracks in residential garage slabs. 10 Minute Mender fills them full-depth and is drivable in minutes, so a weekend repair is genuinely a same-hour repair. The repaired floor can be coated or painted once cured.
Shop and commercial floors. Forklift wheels, dropped tools, and constant traffic chew up control joints, spalls, and cracks. Mender restores the load transfer across the joint or crack so the edge stops breaking down, and the fast cure means a repair during a shift change instead of a shutdown.
Warehouse and industrial slabs. At scale, the dam-and-flood method lets a crew chase thousands of linear feet of shrinkage cracking quickly. This is exactly how 10 Minute Concrete Mender was used at a multi-level Amazon warehouse — sacrificial weatherstrip dams alongside each crack held the water-thin Mender as it seeped to full depth and gelled in minutes, with excess ground flush and the floor returned to service the same day. No saw-cutting, no extended downtime.
Specialty floors. Freezer and cold-storage floors (the standard version cures below freezing), fire-damaged concrete, and any slab that has to bond to concrete, masonry, steel, or wood. For decorative or exposed-aggregate floors that see sunlight, use MatchCrete Clear instead, since Mender will amber in UV.
Garage vs Basement — Which Product Is Right for Each Floor Both floors crack for similar reasons, but the deciding factor is odour and ventilation. The standard 10 Minute Mender in this kit is the right choice for garages, shops, and warehouses — well-ventilated spaces where its faster, colder cure is an advantage. For a finished basement or any occupied interior room, the low-odour Mender LO version is recommended so there is no lingering smell during and after the repair, with very similar performance. If your project is indoors and occupied, ask for the LO version when ordering, or see the specifications below to compare the two side by side.
Technical Specifications
10 Minute Mender — Standard Version Mix Ratio 1 1 Dual Cartridge Volume Total 600 ml Viscosity 7.7 cps Hardness @ 72F (22C) 72 D Compressive Strength (neat) 3883 PSI Compressive Strength (with sand) 6681 PSI Elongation 4 % Tensile Strength 3385 PSI Average Modulus 150.7 ksi Bond Strength, ASTM C882-99 1984 PSI V.O.C. (mixed) 5.5 g/l Solids 98 % Cured Color Grey Gel Time @ 72F (22C) 6-7 min Cure Time @ 72F (22C) 10 min Application Temperature Range -30F 120F Packaging 600ml, 2 Quart, 1 Gal, 2 Gal, 10 Gal
10 Minute Mender — LO Low Odour Version Mix Ratio 1 1 Dual Cartridge Volume Total 600 ml Viscosity (approx) 150 cps Hardness @ 72F (22C) 70 D Compressive Strength ASTM D695 2770 PSI Compressive Strength (with sand) 1680+ PSI Elongation ASTM D638 15 % Tensile Strength ASTM D638 1462 PSI V.O.C. (mixed) 0 g/l Cured Color Off White Gel Time @ 72F (22C) 6-7 min Cure Time (tack free, approx) 20 min Application Temperature Range 0F 95F Packaging 600ml, 2 Quart, 1 Gal, 2 Gal
Garage Floor Crack Repair as a DIY Project Repairing a garage floor crack is a realistic do-it-yourself project. The process is straightforward and the instructions are basic: clean and prep the crack, dispense the Mender, add sand where the crack is wide, and grind flush once cured. The one judgment call to make first is whether the cracking is normal surface aging or a sign of a deeper structural issue — large, frequent, or uneven cracks are worth an assessment before you patch. If you are unsure, NextStar technical support can help you decide over the phone.
Before starting, have the basic tools ready: a hand grinder with a dust shroud, a shop vacuum, a small trowel, and clean dry silica sand to mix with the product. If you do not already own them, they are a one-time purchase that will serve this and future projects.
FAQs About Garage and Shop Floor Repair
How many feet of crack will one kit repair?
The 2-cartridge kit repairs up to about 40 linear feet of 1/8-inch-wide crack when extended with silica sand. Wider or deeper cracks and spalls use more product per foot. For larger jobs, the Mender is available in 2-quart, 1-gallon, 2-gallon, and 10-gallon packaging.
How soon can I drive or park on the repair?
At about 72F the standard Mender gels in 6 to 7 minutes and is hard enough to grind, coat, or take traffic in roughly 10 minutes. The low-odour LO version is tack-free in about 20 minutes. Cooler temperatures lengthen these times.
Can it be used on a commercial shop or warehouse floor?
Yes. 10 Minute Concrete Mender restores load transfer across cracks and control joints and carries forklift and vehicle traffic. It has been used for full-depth crack repair at industrial scale, including a multi-level Amazon warehouse with thousands of linear feet of shrinkage cracks repaired full-depth with no saw-cutting and the floor returned to service the same day. The dam-and-flood method lets a crew chase long runs of cracking quickly.
What can happen if I neglect garage or shop floor cracks?
Left open, a crack lets water and debris under the slab, the edges break down under traffic, and the slab can move and deteriorate over time, turning a simple repair into a larger one. Sealing cracks early protects the floor and any coating on it.
Will the repair match my floor color?
The standard Mender cures light grey; the LO version cures off-white. Both amber slightly over time, which does not affect strength but is visible. To blend a repair, have exterior paint tinted to a concrete sample and dab it over the cured area — this also protects the repair from UV ambering. For decorative or exposed-aggregate concrete, use MatchCrete Clear instead.
Can I store unused product for later?
Yes. Stored properly, the product lasts at least one year from purchase. The LO low-odour version should be used within one year.
What are the most common DIY mistakes?
The two most common are dispensing too much Mender too fast on the first attempt, and using damp or dirty sand, which makes the Mender foam. Both are fixable — grind the area flush with a diamond cup wheel and dust shroud, then reapply. Use only clean, dry silica sand.
When is a crack more than a surface issue?
If one side of the crack sits higher than the other, the slab may have lost support underneath (washed-out soil or missing reinforcement). A surface repair will not fix settlement. Where reinforcement is the issue, carbon fiber stitching or staples can restore tensile strength across the crack — call us to discuss the right approach.
Questions on your floor? Call NextStar free technical support at
1-866-445-3984 — we help homeowners, shops, and contractors size and plan every floor repair. We also offer this product in
2-quart easy-to-use kits and larger bulk packaging.
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