Polyurethane 102 Injection Foam for Non-Structural Cracks

1. Get the concrete above 10°C (40°F) before injecting. Cure and flow both suffer in cold concrete. On an insulated basement, remove the section of insulation over the crack and let the wall come up to temperature — wait until the concrete itself is above 10°C (40°F), not just the room air, before you start.
2. Warm the cartridge. In a cold shop or on a cold wall, viscosity climbs and the material is harder to push. Warming the dual cartridge in hot water lowers viscosity and improves flow into tight and hairline cracks.
3. Mind the substrate moisture. 102 reacts with moisture to expand, so a damp or actively leaking winter crack is ideal — on a dry crack, inject a little water before injecting to kick off the reaction.
4. Let it cure before backfill or finishing. Cooler temperatures slow cure; give the foam full cure time before pulling ports or closing the area back up, and re-insulate once the repair has set.

1. Prepare the crack. Remove loose concrete, dust, and debris along the full length of the crack so the surface seal and ports bond cleanly.
2. Set the ports. Place surface ports over the crack at intervals roughly equal to the wall thickness, starting at the bottom and working up.
3. Seal the face. Apply surface seal paste over the crack between ports to cap it, leaving the port openings clear. Allow the seal to set.
4. Load the tool. Insert the dual 600ml cartridge into the dual cartridge tool, attach the retaining nut, and fit the 1/4 x 24 static mixer.
5. Inject from the bottom up. Inject at the lowest port until material appears at the next port up, then cap and move to that port. Repeat up the crack.
6. Let it react and cure. The resin reacts with moisture in the crack and expands to fill the void. Allow it to fully cure before removing ports and trimming the surface seal if desired.

What size cracks is NextStar 102 used for?
NextStar 102 is the standard polyurethane for non-structural poured concrete wall cracks from 1/32" to 3/16". For cracks wider than 3/16" up to 1/2", or for void filling, use NextStar 103.

How much does NextStar 102 expand?
It expands up to 20 times its original volume, forming a flexible closed-cell hydrophobic foam that fills the crack and the void behind the wall.

Will NextStar 102 expand inside the mixer or tube set?
No. It requires contact with moisture or water to react and expand, so it will not foam in the static mixer or cartridge. This gives the installer more working time than polyurethanes that react in the nozzle.

Can NextStar 102 be used on hairline cracks?
Yes. The cartridge can be warmed in a hot water bath to lower viscosity, allowing the material to penetrate hairline cracks more easily.

Can NextStar 102 be injected in cold weather?
Yes, with preparation. Bring the concrete above 10°C (40°F) before injecting — on an insulated basement, remove the insulation over the crack and let the wall warm up first. Warming the cartridge in hot water also improves flow in cold conditions.

Is NextStar 102 a structural repair?
No. It is a flexible, non-structural repair designed for cracks where more than 20% movement is anticipated. For structural reinforcement use an epoxy, NextStar 120 structural foam, or a carbon fiber system.

What comes in a NextStar 102 tube set?
Each dual 600ml tube set (two 300ml cartridges) ships with the retaining nut and a 1/4 x 24 static mixer included.