How to Permanently Repair Cracks in Concrete Floors

CrackWeld® Concrete Floor Crack Repair Kit CrackWeld easily fills the full depth of stress cracks in concrete floors without the need to chisel or route the crack. CrackWeld quickly cures as a rigid compound that becomes stronger than the concrete itself! It "welds" the concrete slab together and provides to contractors and homeowners the state-of-the-art method for a proper repair of hairline or wide cracks (up to 1/2") in concrete floors, as well as spalls or holes in concrete slabs.

Concrete Slab Crack RepairWhy Crack Repair Should Not Be Ignored – Cracks are one of the most common problems in indoor or outdoor concrete slabs, basement floors, driveways, garage floors, patios, pool decks and parking areas. If a crack is not properly repaired, the situation will get much worse, causing spalling and disintegration of the concrete.

  • RAINWATER – Water gets to the reinforcing steel, makes it rust and expand, causing more cracking and concrete pop-outs.
  • FREEZE-THAW – Freeze-thaw cycle of trapped water widens concrete cracks.
  • SEEPAGE – The seepage of water, water vapor, and radon gas through cracks into homes and buildings.
  • TRAPPED MOISTURE – Moisture destroys flooring materials and may cause mold infestation.
  • EFFLORESCENCE – Water leaches out the concrete and causes efflorescence.
  • TRAFFIC – Vehicular traffic crumbles the edges of cracks.
  • EXPANSION/CONTRACTION – The cracks will get wider and longer due to natural movement of concrete.
  • FLOORING AND OVERLAYS – Cracks propagate into rigid flooring tiles or concrete overlays.

Increase Concrete Density with RadonSeal®

Order Today

How To Order: For secure and encrypted online processing of your order, click Order Now below. All major credit cards accepted, or order with your PayPal account, or through Google Checkout. Or simply phone your order in.

CrackWeld® DIY & PRO Concrete Floor Repair Kits
Size Price Shipping  
CrackWeld DIY Kit (2-Pack) $79 $9 Order Now button
CrackWeld DIY Kit (4-Pack) $139 $10 Order Now button
CrackWeld PRO Kit $184 $12 Order Now button
CrackWeld PRO (Consumables Kit) $119 $10 Order Now button

Shipping: Based on shipping by courier to the lower 48 states. CrackWeld is not sold in stores but is shipped directly from the factory to your door (via UPS). Orders received by 2 pm ET are normally shipped the same day and UPS Ground delivers in 2 to 5 working days. For shipping to other states (AK, HI) please inquire first by e-mail or telephone. No expedited shipping for CrackWeld. Unopened kits in salable condition are returnable - please review our Product Returns

The CrackWeld Advantage for Repairing Cracks in Concrete Slabs

CrackWeld DIY floor repair kit
CrackWeld 4-Pack
  • NO ROUTING NEEDED –Eliminates the need of a cold chisel, or grinding disk.
  • FILL HAIRLINE CRACKS – Low viscosity, self levels. Needle nozzles included to seal even hairline cracks.
  • FAST CURING – Cures rigid in 15 minutes for overlays, flooring, paint, heavy traffic.
  • STRONGER THAN CONCRETE - Bonds concrete to prevent elongation and yawning of cracks.
  • FREEZING - Can be applied in sub-freezing temperatures.

CrackWeld® is a two-component compound. When ejected out of the cartridge through a mixing nozzle, it fills the crack, reacts, and quickly cures. Similar to epoxy but only 1/10 as viscous – routing is not needed! It bonds with sand into an indestructible, impermeable mass inside cracks, spalls, or holes. Water, vapor, or gases cannot penetrate. It is also a structural repair – it stops the crack from further movement.

The repair is rigid. CrackWeld is not suitable for joints that require flexibility like expansion control joints (saw cuts) or floor-to-wall joints of basement floating slabs. For sealing cold joint, expansion joints, and floor-to-wall joints use ElastiPoxy Joint & Gap Filler Kit

Easy Application

CrackWeld DIY floor repair kit
CrackWeld 2-Pack

Easy Enough For A Novice – The inside of the crack must be clean and dry. (Some contractors first place duct tape on both sides of the crack to make cleanup easier, particularly on rough surfaces.) Please follow these basic steps:

  1. Inject the CrackWeld resin into the crack to wet the surfaces and make them tacky.
  2. Push dry silica sand into the crack to fill it.
  3. Thoroughly saturate the sand with CrackWeld resin to fill it to the surface.
  4. In 10 to 15 minutes, scrape off the surface to make it level and use sandpaper for neat appearance.

Hairline cracks that are too narrow for sand are filled and repaired with two passes of the CrackWeld resin. To repair wide cracks or cracks with a void underneath, first fill the crack partially with sand to prevent the CrackWeld resin from running out. If additional sand is needed, use a DRY graded sand (no fines) or ideally, sandblasting sand with granulation like table sugar (30 to 40 grit).

CrackWeld Cures Quickly! – Maintain an steady flow of CrackWeld through the mixing nozzle or it may become plugged after a minute or two! After a stoppage, purge the mixer into a disposable cup. To minimize stoppages, repair small sections of the crack at a time say, 5-10 ft. or use up the whole cartridge. Fill the crack with sand in 2 to 3 minutes after priming while CrackWeld is still tacky. On larger jobs, try to get a helper to do the scraping.

 

The CrackWeld® DIY Concrete Floor Repair Kits are designed for a quick and easy do-it-yourself application by homeowners. Each kit includes either two (2-pack) or four (4-pack) two-component CrackWeld cartridges, as well as mixing nozzles, a bag of silica sand, and other accessories.

Coverage: For full-depth repair of a standard 4” slab, each CrackWeld kit will repair:
        CrackWeld 2-pack ... up to 50 ft. of a 1/16” crack or 25 ft. of a 1/8" crack
        CrackWeld 4-pack ... up to 100 ft. of a 1/16” crack or 50 ft. of a 1/8" crack

Tools Needed – caulking gun, paint scraper or trowel and sand paper (80 grit).

Color – When cured, CrackWeld has a gray color but when exposed to direct sunlight it may change hues. Broadcasting sand over CrackWeld (silica sand is included) before it cures will result in a lighter gray color. Sanding or better yet, grinding the repair even with the sidewalk will reduce the polymer's exposure to sun. Due to the high silica content of the repair (about 80%) the surface usually holds some stain or paint.

The Wrong Way to Repair Cracks in Concrete Slabs

Self-Leveling Polyurethane Caulk – Covering the crack with caulk is cheap and easy but short-term. Water wicking through the concrete or trapped water vapor will weaken its bond to concrete, which may show up as efflorescence. The caulk will not last in traffic. After a couple of years, the caulk gets loose and can be easily peeled off.

Hydraulic Cement – Hydraulic cement is a temporary fix only. Yes, it is waterproof but it does not bond well to concrete – that’s why you have to chisel out the crack as an inverted V-groove to hold it in place. It also is more rigid than concrete. However, concrete continually moves, shrinks and expands which loosens the stiff hydraulic cement. After a couple years, water seepage and likely also efflorescence will appear around the edges of the plug.

For Contractors - CrackWeld® PRO Floor Repair Kit

CrackWeld floor repair kit
CrackWeld PRO Kit

The Complete Contractor Toolkit – The CrackWeld® PRO Concrete Floor Repair Kits are for contractors or homeowners with extensive slab cracks. The two-component CrackWeld compound is packaged in dual-tube cartridges. Each kit is complete and "ready to go." It includes a professional dual-cartridge gun, as well as mixing nozzles, a bag of silica sand, and other accessories.

Coverage: For full-depth repair of a standard 4” slab, each CrackWeld Pro kit will repair up to 100 ft. of a 1/16” crack or 50 ft. of a 1/8" crack.

Purchasing Extra Material – In case additional materials are needed a contractor can purchase our CrackWeld® PRO Consumables Kit. The consumables kit is similar to the full PRO kit except for the dual-cartridge gun and gloves.