High Pressure DIY Foundation Crack Injection Repair kit

High-Pressure DIY Foundation Crack Injection Kit — Up to 4,500 PSI

Stop Actively Leaking Cracks — Works on Wet, Dry, and Previously Repaired Foundation Walls

Actively leaking poured concrete foundation wall cracks
Hairline cracks as narrow as 0.002 inch
Previously repaired cracks — penetrates past hydraulic cement without chiseling
Expanding foam fills the full crack — expands up to 25× on contact with water
Injection pressure up to 4,500 PSI — reaches the narrowest voids
New no-leak applicator design with air inlet valve
Repairs 8–12 ft of 8 inch thick poured concrete wall per kit
Free NextStar Technical Support — 1-866-445-3984
Discounted shipping USA & Canada

When You Need High Pressure — Active Leaks and Failed Low-Pressure Repairs

High-pressure injection is specifically designed for cracks that are actively leaking, very narrow (as fine as 0.002 inch), or that have been previously patched with hydraulic cement and are leaking again. If a low-pressure repair did not hold, high-pressure injection drives resin past the failed patch and deep into the crack where low-pressure could not reach. The 100/800 blended polyurethane foam is hydrophobic — it reacts with water and moisture inside the crack, expanding up to 25 times its volume to completely fill the void and expel water.

For standard dry cracks 1/16 inch or wider that require a structural repair, a low-pressure polyurethane kit or epoxy injection kit is more appropriate. Call 1-866-445-3984 if you are unsure which method suits your crack.

What's Included — 25 Packers, Polyurethane, Manual Pump, and Tools

½ Gallon Blended Polyurethane Foam with Activator
100/800 blended hydrophobic polyurethane that expands on contact with water or moisture, sealing and expelling water as it fills the crack.

25 — ½ inch Mechanical Injection Packers
Drill-in mechanical packers that seat directly into the wall and withstand injection pressures up to 4,500 PSI.

High-Pressure Dual Piston Injection Tool
Modified applicator engineered to achieve pressures above 2,500 PSI manually. New no-leak design with air inlet valve — unlike standard high-pressure kits on the market.

Packer Installation Tool
Drive packers in safely without damaging the zerk fitting.

Safety Goggles

3 Pairs of Gloves & Mixing Cup

Complete Step-by-Step Instructions

Free Technical Support

Upgrade option: Add 25 additional packers and increase polyurethane volume to 1 gallon — ideal for longer cracks or heavily fractured walls.

4,500 PSI vs Low-Pressure — Side-by-Side Comparison

The core difference is how deep the resin travels and what conditions it can handle. High-pressure forces polyurethane into voids low-pressure cannot reach, which is why it succeeds on leaking, ultra-fine, and previously-failed cracks.

Step-by-Step — How to Use the High-Pressure Kit

1. Put on all protective gear first. Before handling any materials, put on the supplied safety glasses and rubber gloves. Wear them throughout the entire repair. If reusing the injection tool after the job, flush it immediately with solvent, then pump light engine oil through to prevent remaining polyurethane from solidifying inside.
2. Drill packer holes. Using a hammer drill with a ½ inch masonry bit, start about 3 inches from the bottom of the crack. Drill holes at a 45° angle approximately 5 inches from the crack so the hole intersects the crack at mid-wall. Do not drill all the way through — halfway through the wall thickness is adequate. Repeat every 6 inches up the crack on alternating sides. For wider cracks, holes can be spaced up to 8 inches apart.
3. Clean the holes. Dust will interfere with injection penetration. Use high-pressure air and vacuum, or a round wire brush inside each hole to ensure clean contact.
4. Install the packers. Use the provided packer installation tool — do not hammer directly on the zerk fitting. Pound in until all rubber is inside the hole and tighten until firm.
5. Seal wider cracks (optional but recommended). For cracks wider than a hairline, seal the surface between packers with hydraulic cement before injecting. This keeps more product inside the wall and keeps the job cleaner.
6. Mix the polyurethane. Add 1 to 2% catalyst (one good squirt per quart). More catalyst means faster reaction with moisture. Mix only 1 cup at a time — that is all that is needed to start.
7. Load the injection tool. Open the high-pressure tool and pour in your first mixed batch. Fill to ½ full maximum. Reassemble, face it downward, and pump until polyurethane comes out the tip. You are ready to inject.
8. Inject from the bottom up. Begin at the lowest packer. When you see the foaming reaction moving close to the next packer up (on the opposite side), move to that packer. Continue up to the top.
9. Return to reinject. After reaching the top, return to the first packer and attempt to reinject additional product. Some packers will accept more material than others. You can go back and forth as many times as needed.
10. Leave packers in place. The 100/800 polyurethane stays active for up to a week after injection, continuing to react with any moisture in the wall. Leave packers in place for approximately 7 days. If needed, the tip can be removed and the stud left in the wall. Clean up any cured excess material.

Catalyst Usage Guide

The reaction profile is adjusted by the amount of catalyst added. At 1.25% (½ pint per 5 gallons), expansion starts in about 35 seconds and completes in approximately 3.5 minutes after water contact. At 2.5% (1 pint per 5 gallons), expansion starts at 25 seconds and completes in about 2 minutes. These times are based on 77°F with 2.5% water added.

Common Questions About High-Pressure Crack Injection

Have a question during your repair? Call our free technical support line at 1-866-445-3984 — our team is available to help throughout your project.