HMI

Just because a slab is level doesn’t mean it’s supported.

That’s where undersealing comes in. Instead of raising the concrete, the goal is to fill unsupported areas and restore support underneath.

Lifting fixes elevation. Undersealing fixes support.

See how it works and when to use it:

What is Undersealing? How is it different from concrete lifting? Undersealing is the process of introducing material beneath a slab to restore support where contact has been lost. Unlike a typical lifting project, the objective is not necessarily to change the elevation of the concrete.

Ever wonder where the foam actually goes once it’s under the slab?

Voids, loose base, joints, cracks, and other conditions below the concrete can all affect how polyurethane moves.

Watch how the foam responds—and what that response can tell you about what’s happening underground.

Want to dig deeper into how foam travels beneath concrete?
🟥Read the full blog: https://hmicompany.com/foam-travels-underground/

How Polyurethane Foam Moves Underground Polyurethane foam can take different paths underground depending on...

Soil improvement can open the door to projects beyond traditional concrete lifting.

Join HMI for our Soil Improvement Seminar and get hands-on with the tools, materials, and techniques used to tackle real-world soil problems.

Learn about:
▪️Deep Foamjection
▪️Permeation grouting
▪️Seawall repair
▪️Soil testing with DCPs
▪️Designing & bidding soil improvement projects

You’ll learn alongside experienced industry professionals and walk away with practical knowledge you can take back to the field.

Add more capabilities. Take on more projects.

🟥More engineering support is coming to Team HMI!🟥

This October, we’re adding another geotechnical engineer to the HMI team; giving our contractors another technical resource to turn to when tough jobs come up.

Stay tuned. We’ll introduce the newest member of the team soon!

You pull the trigger, the foam goes in, and the slab starts moving. But what’s actually doing the lifting?

It’s more than just foam expansion.

The foam first fills the open space beneath the slab. As that space gets tighter, pressure builds. Once there’s enough pressure, the concrete starts to move.

Understanding what’s happening under the slab can help you understand why one injection point may react differently than the next.

Check out our latest blog to learn more: https://hmicompany.com/2026/09/17/what-actually-lifts-concrete/

Thinking about starting a concrete lifting business? Bought used equipment or took over an existing operation?

🟥Start with the right training.

HMI’s 2-Day Training Seminar covers the hands-on skills and the business side - equipment, estimating, bidding, maintenance, marketing, and more.

Whether you’re starting from scratch or already have the equipment, get the training to put it to work.

🟥Learn more & register: https://hmicompany.com/training-support/2-day-beginner-seminar/

Watching a slab move fast feels good; but faster foam doesn’t always mean a better lift.

If the foam reacts too quickly, it may start building up before it has a chance to spread where you need it. That can mean more holes, more drilling, more material, or areas under the slab that still need support.

The goal isn’t to see how fast you can move the concrete. It’s to get the foam where it needs to go and leave the slab properly supported.

We break down it down in our latest blog:

Why Faster isn't Always Better in Polyurethane Concrete Raising Faster-reacting polyurethane can be extremely useful.But faster isn't automatically better.As reaction speed increases, the material generally has less time to travel before it begins building structure. If the foam doesn't reach the full treatment area, voids or areas of inadequate support may rema...

Traditional backfill works. But not every job makes it easy.

Limited access. Hard-to-compact areas. Large voids. Weight concerns. Too much equipment needed on site.

That’s where FillFoam™ can offer another option.

FillFoam is produced on site and pumped directly where it’s needed.

🟥Watch FillFoam vs. Traditional Backfill to see how the two methods compare:

FillFoam vs. Traditional Backfill: What’s the Difference? Traditional backfilling is a proven solution—but it isn't always th...

When it comes to polyurethane foam, reaction speed can affect how far the material travels beneath the slab before it builds structure.

Knowing the difference can help you choose the right foam for the job.

Read the full breakdown here: https://hmicompany.com/reaction-speed-vs-spread-why-it-matters-in-concrete-lifting