Cold floors? Not on our watch. Pair underfloor heating with polished concrete and you’ve got a home that’s warm, quiet, efficient—and frankly, hard to leave on winter mornings. The two systems were made for each other: one delivers steady radiant heat, the other stores and releases it like a champ. At NZ Grinders, we’ve worked on plenty of heated slabs, and we’ve learned exactly how to get that velvety-warm, magazine-ready finish without nasty surprises.

Why They Work So Well Together

Polished concrete brings thermal mass to the party. It soaks up the gentle heat from the coils or cables and releases it slowly and evenly. No hot blasts. No cold corners. Just a stable temperature that feels like you’re living inside a hug.

Because radiant heat warms objects (and people) rather than just air, you can usually set the thermostat lower and still feel comfortable. That means fewer on/off cycles, less energy waste, and a house that doesn’t yo-yo between “arctic” and “sauna.” Add good glazing and sensible insulation, and your slab becomes the quiet engine of winter comfort.

Hydronic vs Electric: Which Plays Nicer With Polished Concrete?

Hydronic (Water-Based)

Hydronic systems pump warm water through PEX tubing embedded in the slab. They’re brilliant for whole-home heating and large, open areas.

• Pros: Lowest running costs on big jobs, buttery-even heat, works well with heat pumps and solar.
• Consider: More planning and plumbing. Pressure-test the loops before and after the pour, and again before we arrive to grind.

Electric (Cable or Mat)

Great for smaller zones—think ensuites, entries, and studios—where quick installation wins the day.

• Pros: Faster to install, ideal for renovations or single rooms.
• Consider: Running costs can be higher for big footprints. Use quality thermostats with floor sensors to avoid overcooking the slab.

Our rule of thumb: Hydronic for large, lived-in spaces; electric for targeted zones. We’ll happily coordinate with your heating contractor either way.

Design & Build: Get the Slab Right from Day One

A world-class finish starts before the concrete truck arrives. Here’s what sets you up for success:

• Insulate beneath and at slab edges. Rigid insulation stops precious heat diving into the ground instead of your toes.
• Keep the slab flat. We need excellent finish tolerance for a premium polish. Ripples and birdbaths don’t disappear with shine.
• Mind the mesh and pipes. Tie hydronic loops securely and keep them at a consistent depth. We’ll grind the surface, not play archaeological roulette.
• Skip curing compounds. They may interfere with densifiers and sealers.
• Document everything. Photograph pipe layouts and keep as-builts. Future-you will love past-you for this.
• Control joints and movement. Plan joints around doorways, hallways, and island benches. We’ll detail them cleanly for a designer look.

Loop depth matters: aim for enough cover above hydronic pipes so our early passes contact concrete—not copper or PEX. We’ll advise before the pour if you loop us in early (the best time to call NZ Grinders is yesterday).

Finish Options That Love Heat

You’ve got range—without resorting to coatings that age poorly.

• Marble surface polish (no to minimal stone exposure). Soft, subtle, and refined. Beautiful in contemporary homes; works a treat with radiant heat.
• Salt & pepper exposure. A gentle peppering of fines for a crisp, architectural vibe.
• Full stone exposure. Bold and textural; think terrazzo energy with serious durability.

Gloss is your choice: matte and satin give grip and hide dust; high gloss turns lobbies and living rooms into light amplifiers. We’ll match the finish to your foot traffic and cleaning routine.

Smart Heating: Comfort Without Bill Shock

Radiant slabs prefer low and slow. Treat them like a cruise ship, not a jet ski.

• Pick a steady set point. Nudge temperature, don’t swing it. Big changes waste energy and don’t feel faster.
• Use zones. Sleep areas cooler, living zones warmer. Your thermostat should have floor sensors in tiled or small rooms.
• Mind the rugs. Thick rugs insulate the slab. If you love them, keep sizes reasonable and avoid wall-to-wall coverage.
• Let the slab do the work. Sun streaming in? Your mass will help buffer it. Don’t crank the heat; let the slab coast.

Common Myths We Hear (And the Reality)

• “Polished concrete cracks when the heat’s on.” Concrete cracks when design, joints, or curing are wrong. Good detailing and placement stop drama before it starts.
• “It’s slippery.” Finish selection and cleaning matter. Satin or matte finishes, plus sensible entry mats, keep traction high. We can provide a bush hammer to the surface if you want it extra grippy
• “It’ll be dusty.” We densify the surface and refine it—no dusting. That’s old, unsealed concrete talking.
• “It needs constant resealing.” A true mechanical polish doesn’t rely on a film sealer. That shine is in the concrete, not on it.

Costs, Value, and Why This Combo Wins Long-Term

Upfront, a heated, polished slab is an investment. Over time, it pays you back with lower maintenance, fewer finish replacements, and real comfort gains. No carpet to replace, no timber to resand, no vinyl seams to fail. Just a durable, elegant surface that does double duty as the heart of your heating system.

And yes—your toes will send thank-you notes.

Talk to NZ Grinders Early (Your Future Floor Will Thank You)

We’re concrete nerds with warm feet and strong opinions, and we’ll put both to work on your project.

For project-specific advice or information, give us a call:
📍 North Island – Glen: 021-434-199
📍 South Island – Mike: 027-281-8815
📧 Or email Ian, our sales manager, via our Contact Page.

Let’s design a slab that heats beautifully and looks incredible—finished by NZ Grinders the right way, the first time.