Underfloor Hydronic Heating — In-slab, Screed, Minitec, Spider Board | 1st Choice Heating & Cooling
Hydronic underfloor heating

Warm floors, invisible system — real comfort underfoot

Hydronic underfloor heating warms your home from the ground up. Hot water flows through pipes laid in the slab, screed, or between joists — turning the floor itself into a quiet, even radiator. We design and install five different systems to suit new builds, renovations and retrofits.

★ 4.9 Google rating 5 system types New builds + retrofits Heat pump compatible
A family in robes on warm tiled floors — the kind of everyday comfort hydronic underfloor heating delivers. South East Melbourne
Why underfloor

The most even, invisible heating there is

Wall-mounted radiators do a great job, but underfloor takes hydronic heating one step further — the whole floor radiates gentle warmth, every corner of the room is the same temperature, and there's nothing on the walls or in the way.

Warm floors underfoot

The most noticeable everyday benefit — cold tile and timber floors become comfortable to walk on, especially in bathrooms, kitchens and ensuites.

Completely invisible

No wall panels, no vents, no visible equipment. The system is hidden inside the floor itself — freeing up every wall for furniture, art and design.

Genuinely even heat

The entire floor surface radiates warmth at once — no cold spots, no hot zones near the heat source. Just consistent room temperature, edge to edge.

Pairs with heat pumps

Underfloor's lower flow temperatures (30–45°C) match modern electric heat pump output perfectly — the most efficient hydronic pairing available.

Choose your system

Five underfloor systems — one for every home stage

Underfloor heating isn't a single product — there are five distinct installation methods, each suited to different home stages and floor situations. The right system depends on whether you're building new, renovating, or retrofitting, and how much floor height you can give up.

System 01

In-slab

Heating pipes are embedded directly inside the concrete slab as it's poured. The slab itself becomes the radiator — releasing warmth slowly and consistently across the entire floor. Highly thermally massive: takes longer to warm up, but holds heat beautifully.

Best forNew builds only
Install stagePre-pour
Floor height addedNone
System 02

In-screed

Pipes are clipped to positioning boards laid on top of the existing slab, then covered with a concrete screed layer. The most efficient underfloor system — less thermal mass between pipe and surface means faster response and lower energy loss.

Best forNew + existing
Install stageRenovation
Floor height added~40–60mm
System 03

Minitec

The thinnest underfloor heating system on the market — only 15mm total height including the self-levelling compound. Designed specifically for retrofits where every millimetre of floor height matters (doors, transitions, head-clearances).

Best forRetrofits
Install stageExisting home
Floor height added15mm
System 04

Spider board

Pipes clip into a moulded panel (the "spider board"), which is then covered with either concrete screed (40mm) or self-levelling compound (22mm). A flexible mid-tier option that suits both new builds and renovations with a bit of floor height to spare.

Best forNew + reno
Install stageFlexible
Floor height added22–40mm
System 05

Heat emission plate

Aluminium plates with a pipe groove are installed between floor joists, beneath the floorboards. Designed for timber-framed floors where lifting boards is easier than adding thickness. Quiet, low-profile, no impact on floor height.

Best forTimber-frame floors
Install stageFloor lift required
Floor height addedNone
Compatibility

Works with everything that matters

All five underfloor systems are compatible with both gas boilers and electric heat pumps, work under most floor finishes including tile, timber and polished concrete, and pair cleanly with reverse-cycle cooling for year-round comfort.

We confirm the exact specification — pipe layout, flow temperatures, finish compatibility — as part of the design phase before any quote is finalised.

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Compatible with

Gas boilers (existing or new)
Electric heat pumps (air-to-water)
Hybrid heating systems
Underfloor cooling (most systems)
Tile, stone & polished concrete
Most engineered timber floors
Common questions

Underfloor heating questions answered

Which underfloor system is right for my home?

It depends on three things: whether you're building, renovating, or retrofitting; how much floor height you can afford to lose; and the floor type underneath. For new builds, in-slab or in-screed is usually best. For renovations, in-screed or spider board. For retrofits where height is tight, Minitec. For timber-floored homes, heat emission plates. We confirm the right choice during the assessment.

How long does underfloor heating take to warm a room?

Longer than radiators — typically 1–2 hours from cold, depending on system type and floor mass. In-slab is the slowest (high thermal mass) but holds heat longest. Minitec and screed systems respond faster. Most homes set their underfloor on a schedule so it warms up before you need it, then cycles efficiently throughout the day.

Can underfloor be installed under timber floors?

Yes — Minitec, spider board, and heat emission plates are all compatible with engineered timber. We work within the manufacturer's surface-temperature limits to protect the timber. Solid hardwood is trickier and we'll advise on a case-by-case basis. Tile and polished concrete are the easiest pairings.

Will it work with my existing gas boiler, or do I need a heat pump?

Both work. Underfloor's lower flow temperatures (30–45°C) pair particularly well with electric heat pumps, but gas boilers also run them efficiently. If you're planning to switch from gas in the future, underfloor is the best emitter to install now — see our electric heating page for more.

Can I get underfloor cooling too?

Most of our underfloor systems support cooling as well as heating — chilled water circulates through the same pipes in summer. It's not as powerful as forced-air cooling, but it provides gentle background comfort. We can specify it during design. For full cooling capacity, we typically pair underfloor heating with a separate split or ducted AC system.

How much floor height will I lose?

Depends on the system. In-slab adds nothing (it's inside the slab). Minitec adds just 15mm. Spider board adds 22–40mm depending on the cover layer. In-screed typically adds 40–60mm. Heat emission plates add nothing (they sit between joists, beneath floorboards). We confirm exact dimensions during design — important if you have doors, transitions, or skirting boards to work around.

What happens if a pipe fails?

It's rare — modern hydronic pipes are designed to last decades — but repair can be tricky for in-slab and spider-board systems because the pipes are encased in concrete or screed. We use high-quality pipe with proven longevity, pressure-test every install, and provide manufacturer warranties. For higher peace of mind, in-screed and emission plate systems are easier to access if something ever does need attention.

Ready when you are

Find the right system for your home stage

Book a free assessment and we'll walk through which underfloor system suits your build phase, floor type and budget — and integrate it with the rest of your hydronic design.