Concrete Crack Repair Made Easy 
Most homeowners have encountered the frustrating problem of leaking cracks in basement
walls. Others have discovered that poured concrete walls hide form wire ties, which rust away and leak. Another problem are leaks around pipes – the hole is drilled one size larger and the gap is just stuffed with mortar, which eventually seeps water or cracks. How NOT to Repair Foundation Cracks The typical homeowner will usually try to fix the foundation crack with caulk. But this is only
a superficial repair. Water will still fill the inside of the crack and cause efflorescence, which will eventually loosen the caulk.
In a couple of years, the caulk will start peeling. Disappointed, the homeowner will pull off the caulk, chisel out the crack, and fill it with hydraulic cement. But
hydraulic cement does not bond well to concrete – it needs an inverted V-groove to hold it in. And it is very rigid. As the concrete continuously moves, shrinks and expands, the rigid "rod" will get loose. Efflorescence ("white powder") will start coming through around it, soon followed by drops of water. After a couple years, water will start seeping
around it. An alternative repair method would be to excavate and patch the foundation crack on the exterior. But this would
cost thousands of dollars and may not be permanent either because surface repairs always get loose or crack. Low-Pressure Concrete Crack Injection Cracks can be found in practically all basements and if they do not leak now, they are likely to leak in the future. In most cases, the common
wall cracks pose no structural concerns and the
problem is just the seepage of water. More on the causes
and types of basement cracks. The main purpose of concrete crack injection is to permanently fill the
full length and depth of the crack to keep water out. Then,
water cannot fill the inside of the crack and deteriorate the concrete, which would widen the crack further. Until recently, concrete crack injection required cumbersome and expensive
high-pressure injection equipment. Diagonal holes had to be drilled
into concrete to intersect the crack and insert injection ports.
This method is still used today but only on large concrete structures
like dams and bridges. Low-pressure crack injection (below 40 psi) has made the repair of cracks
in poured concrete walls or concrete
floors much easier and less costly.
This has made possible an easy do-it-yourself crack repair by homeowners using just a conventional caulking gun:
- no drilling – injection ports are just glued on top of the crack,
- no need for expensive high-pressure equipment.
 View a video on do-it-yourself crack injection (broadband needed).
We supply both types of crack injection polymers, which fill cracks completely and permanently:
- Expandable polyurethane polymer, or
- Two-component epoxy.
Polyurethane Injection Over 95% of residential basement cracks are non-structural – the
only problem is the seepage of water. Expandable polyurethane
is the best choice for most cracks in poured basement walls. While it does not add structural strength, polyurethane forms inside the crack a permanent barrier impenetrable to water. Advantages over epoxy injection:
- The polyurethane polymer has low viscosity to fill hairline cracks but forcefully expands to fill wide cracks (up to 1/2 inch)
- Polyurethane bonds tenaciously to dry or wet concrete – it can be used to repair wet cracks.
- The polyurethane polymer forcefully expands,
which ensures that the full depth and length of the crack is
filled. It fills cracks in walls up to 24 inches (!) thick.
- Polyurethane can expand over 20 times its volume. If there is a
void on the backside of the wall, it will fill it too – there
is no way for water to ever find the crack again. If the crack
is above ground, seal the crack on the other side temporarily with a caulk.
- Polyurethane foam remains flexible, which allows for the continuous natural movement of concrete due to thermal shrinkage and expansion or settling.
During the last decade, great advances have been made in the science of urethanes. We only use the highest-quality polyurethane polymer for both the professional and do-it-yourself kits. We
use hydrophobic polyurethane foams, which repel water. In contrast, hydrophilic
foams absorb water but when allowed to repeatedly dry out, like
in a basement, they release the water molecules and gradually
crumble. Epoxy crack injection does not only stop water but also provides structural strength. Like the familiar epoxy glue, it fills the crack and “glues” the concrete. Its strength and bond with concrete greatly exceed the strength of the concrete itself. And the high bond and tensile strengths of epoxy prevents further elongation and yawning of structural cracks. However, epoxy cannot hold the whole structure together. Unless the underlying cause of the structural stress is resolved, a new crack is likely to develop parallel to the repaired crack. Compared to expandable polyurethane, injecting epoxy is more exacting:
- epoxy adheres only to dry surfaces, making the repair of a leaking or wet cracks impossible,
- epoxy cures slowly and may run out from the other side of the crack before it can harden,
- epoxy does not expand - a 1/4-inch crack needs four times more (!) epoxy than a 1/16-inch crack.
We make epoxy crack repair kits for to both contractors and homeowners. Surface Sealers The standard crack injection kits include epoxy Surface
Sealer and Port Adhesive. After "gluing" on the injection ports, spread on the Surface Sealer 3/4" to 1" on each side of the crack. The epoxy in the do-it-yourself kits cures slower, making it more forgiving. Its "mixing time" (before it gets too hard to spread) is 8 minutes and it cures hard enough for injection (fingernail hard)
in about 2 to 3
hours. The professional epoxy surface sealer
should be applied within 5 minutes and it cures much faster - in 30 to 40
minutes. After completing the crack repair, knock off the injection ports. The gray epoxy layer stays on the surface. This is not an issue if the wall will be covered up but when appearance
matters, you have to remove the hard epoxy with
a grinder or a chisel and hammer. If the end appearance counts, the Easy-Peel Surface Sealer
& Adhesive provides an easy solution. After the
injection urethane cures, just peel off at once the entire
surface seal together with injection ports. A neat
and clean concrete surface but without grinding or chiseling. Easy-Peel
is available for both professional and do-it-yourself kits. The Easy Peel sealer is particularly suitable for fixing cracks in concrete
slabs and for floor-to-wall joints where appearance matters. For more
info see How
to Repair Cracks in Concrete Slabs and Floor-to-Wall Joints Foundation Crack Injection Kits We provide concrete crack repair kits to both homeowners and contractors.
Professional contractors receive technical consultations,
additional parts and materials as required, and a wide choice of surface sealers and injection polymers for special
applications. Do-It-Yourself
Foundation Crack Repair Kits
Each crack injection kit repairs up to 8–10 linear ft. of concrete
cracks. The kits are complete, only a conventional caulking
gun is needed. Professional
Foundation Crack Repair Toolkits
Each toolkit repairs about 30 (or 60) linear ft. of concrete
cracks. Also suitable for homeowners with lots of cracks to repair
or to fill a long floor-to-wall joint. Complete toolkits, including
a professional dual-cartridge caulking gun. Temperatures: The concrete temperature should be above 40° F, preferably above 50° F.
Storage: Dry conditions, preferably at room temperatures. Shelf life at least 1 year. When to Use the Pipe Perforation Mender Kits The Pipe Perforation Mender Kit is similar to the D-I-Y Foundation Crack Repair Kit. All you need is a common caulking gun. First, install one or more injection ports around the pipe and enclose the opening with the surface sealer. Let cure and inject the polyurethane, which forcefully expands and fills the entire gap around the pipe with polyurethane foam. The polyurethane
tenaciously
adheres to concrete, plastic, and metals. It beats caulking, mortar, hydraulic cement, or patching compounds. It will never separate, peel, or leak – it is permanent. Common uses:
Pipe perforations through poured concrete or brick walls: The urethane foam completely fills the entire gap around the pipe through the wall. Suitable for both new construction or already leaking mortar in pipe openings. In case of new construction, inject directly around the pipe. If old mortar is leaking, drill a hole and inject right through the mortar.
Form tie wires or tie rods: The ties hold the forms together when concrete walls are poured. But once the exterior waterproofing breaks down, water attacks the the form ties, making them rust or fall out. Water starts squirting into the basement. Caulking or patching are only temporary. Glue an injection port right on top of the hole and inject the polyurethane, which will stop the leak permanently.
When to Use the Epoxy Crack Filler Kits Epoxy's strength and its bond to concrete are stronger than the concrete itself. If you tried to pull it apart, the concrete would yield first. Unlike injection, Epoxy Crack Filler does not fill the full depth of the crack but it provides a strong surface suitable for heavy traffic in a shop or warehouse. Narrower cracks have to be routed out first before pouring in the Epoxy Filler. Mix in silica sand to allow troweling on walls. But what makes our Epoxy Crack Filler for Concrete or Masonry really special is that it uses flexible epoxy, in order to allow for the continuous movement of concrete. Using the common epoxy, which has no "give," might cause new cracking in concrete next to the repaired crack. Common uses:
Cracks and expansion control joints in industrial floors or garages with heavy traffic.
Long or wider cracks in concrete slabs: More economical than multiple injection kits. Less concern about the material running out at the bottom. Hard and paintable surface.
Cracks in concrete block walls: Crack injection is not suitable because the injection material would uselessly expand into the hollow or poorly filled cores in the blocks. The Epoxy Crack Filler is the best repair for concrete blocks.
Spalls or holes in concrete: Mix in with silica sand and fill the spalls for a permanent repair. Forms a stronger bond than patching.
Any questions? Please contact us by e-mail,
telephone (203) 225-0366 or toll-free 1-800-472-0603
MADE IN USA
Products not sold through retail stores. Available exclusively from:
Radon Mitigation & Waterproofing Concrete Sealer Co.
Novion Inc., 18 L'Hermitage Drive, Shelton, CT 06484 USA
RadonSeal™ is a registered trademark. Copyright © 1998-2008. All rights reserved.
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