NextStar Help Articles & Videos for Concrete Foundation and Crack repair

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Nextstar FAQ, Articles, Videos for Foundation & Concrete Repair
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Technical tips FAQ for Concrete Crack Injection & Repair. Articles, Video Support

FAQ List for Foundation Walls 

The cost can vary depending on the type of crack repair. If it is structural or if it is leaking. An excellent example would be a poured concrete basement wall that has cracked diagonally down from a window to the floor 6 ft long, a non-structural crack. Using a standard polyurethane product would be an excellent choice. A polyurethane kit would cost $140 to $215, depending on the size of the kit purchased. You save on the labor cost if you are buying a DIY kit. This same crack repaired by an experienced foundation contractor may range from $400 to $800 depending on your location, the level of expertise, and any other costs built into this repair such as overhead, warranty, labor, and worker compensation costs. There is no average per ft price by contractors, but the cost could be five times the material costs. If you take this ratio into account when you are adding up the costs, there can be significant savings by doing the work yourself or considering this work as an added service if you are a contractor.

Yes, doing crack foundation injections in the winter can be accomplished by allowing the basement wall exposure to the building's heat by removing any insulation against the wall. It will require 3 or 4 days for the concrete to warm to at least 40 deg f. In extremely cold outside temperatures, you may need to insulate the exterior wall temporarily.

You can inject Epoxy into a structural or non-structural crack. All structural cracks should be injected with Epoxy. A horizontal crack mid-wall or cracks over 1/4 inch wide are considered structural cracks. If a foundation crack is narrower widths, mostly vertical, and leaking, which is very common down from a window, then Polyurethane is an excellent economical choice that will stop water permanently.

NextStar Epoxies come in a variety of viscosities (thickness to flow). They can be as thin as water like the #4 ULV Epoxy for super hairline cracks to thick as butter like the 101 Epoxy Paste for wide cracks. The #4 ULV Epoxy is a slow cure of 4 days. The LV (Low Viscosity), MV (Medium Viscosity), EHV (Extra High Viscosity) are all designed to gel from 20 to 40 min to prevent drain out and will set in 24 hrs at 32deg F. The 101-Epoxy Injection Paste is very thick and designed for wide cracks. It stops flowing when injection pressure stops. All the Epoxies will bond to each other during injection if switching viscosities during the same crack repair.

NextStar 121 Epoxies are designed to cure at 32 Deg F, gel anywhere from 20 minutes to 1 hr, and have an initial cure at 24 hrs. Our E101 Epoxy Injection Paste is engineered to stop flowing when injection pressure is removed and will cure in 24 hrs. The #4 ULV Epoxy is a very slow curing Epoxy and may gel between 1 hr to 8 hrs. Depending on the concrete temperature, it may take up to a week to fully cure.

Generally, all our products will be useful in storage for one year as long as they do not freeze. One exception is the Koster 2IN1 resin is limited by age and should be applied within six months. For more detailed information, click here.

Crack injection repair on a leaking crack can be challenging since attaching injection ports to a wet wall is impossible. One option is to drill a 5/8th hole, 1 inch deep, hammer in corner ports, and seal with Blitz powder or hydraulic cement. Then you can proceed as usual with a low-pressure crack injection using either an Epoxy or Polyurethane. Option 2 uses standard high-pressure crack injection with polyurethane. Insert injection packers and use a modified grease gun or high-pressure pump to do a high-pressure injection.No special preparation is needed, such as the wall be dry first.

1. Wire brush the concrete surface 2. Dry the wall if wet. 3. Attach injection ports. 4. Use the epoxy seal paste to seal the crack between and around ports. 5. Inject Epoxy or Polyurethane. 6. After cure, remove ports if necessary.

2. For High Pressure 1. Drill locations for injection packers. 2. Clean out drill holes and install packers. 3. Inject polyurethane using a pump or modified grease gun. 4. Leave packers in place for 1 week and then remove zerk tips if they are in the way.

A structural crack is usually considered anything larger than a ¼ inch or any width of crack that is horizontal. Many factors could classify a concrete crack as structural or not, such as settling, lateral force, soil erosion, low-quality concrete, damage, fire damage, etc. If in question, it is always advisable to consult a structural engineer. Sample pictures of structural problems. Example of structural cracks with these pictures.

Structural concrete crackBowed Basement Wall Broken concrete footing

Carbon Fiber used as part of a structural repair has many advantages over using steel to reinforce concrete. It is stronger than steel compared to its weight, and it will not rust or corrode. Carbon fiber can be formed or cut in unlimited ways. It has very high tensile strength and very-low elasticity making it ideal for concrete reinforcement repair. It is commonly created as a strap or a grid when used for foundation repair to reinforce a bowed basement wall to prevent the wall from cracking. Carbon Fiber can also be formed as a staple or stitch for either a floor or a wall crack. Carbon fiber has no compression strength, so epoxy crack injection is always recommended to prevent crushing the fiber.

Carbon Fiber Structural concrete crackBowed Basement Wall

Snap ties are metal tabs installed in the concrete forms when concrete is poured to hold the forms together. Snapped off to release the concrete forms, most of the metal tab is left inside the concrete. Over time they can rust and allow water to enter the foundation. Using hydraulic cement, tar, or polyurethane to repair is not recommended because they may fail eventually. The best solution is to use an ultra-low viscosity epoxy to encapsulate the rusting snap tie and provide a permanent solution. The typical repair product solution is #4 ULV Epoxy with an autoinjector.

Snap-tie repairSnap-tie leaks

NextStar offers a much more comprehensive selection of products to repair many different foundation problems encountered versus a one solution fits all. NextStar products are all professional-grade. All epoxy and polyurethane products have a limited life span in storage and NextStar’s supply is continually being replenished, so products are never old when it is sold. The age of the products of many of our competitors is often lengthy and questionable. NextStar does more than sell products; we also have full-time professional technicians servicing our local area regularly. We can provide expert advice on any concrete foundation problem. A service that most competitors are unable to deliver.

Crack injection into poured concrete to waterproof is an easy process, an approved repair method. An injection is not a recommended repair of a cinder block wall because it is hollow; the product will only flow into the hollow, open spaces and not provide waterproofing. The best long-term solution is to excavate the exterior and install a membrane for waterproofing. If the wall is bowed, it may require carbon fiber reinforcement on the interior. Some contractors may propose using a waterproofing drain system on the interior, but if you are in a climate with frost, water may get trapped inside the hollow spaces and cause more damage to the blocks over time.


Weeping tile is a perforated pipe that surrounds the basement just below the exterior's footing level that drains into a sump pump pit to be pumped out or into the sewer or septic tank of some older buildings. This allows groundwater that surrounds the building to drain off.

Weeping drain tile example


No problem. You can contact NextStar at 866-445-3984 press 1 for sales, and we will gladly email out a copy of the instructions for your kit or product


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