Response
Faster reaction than in-slab heating
Because the pipework sits above the structural slab within the screed layer, the heating mass is typically smaller and can respond more quickly.
Hydronic underfloor heating
In-Screed Hydronic Heating
In-screed hydronic heating for Sydney and NSW projects, installed above the structural slab and beneath the finished floor.
Installed above the structural slab
Faster response than in-slab heating
Coordinated with screed and floor finishes
Quiet radiant comfort with hidden pipework
How it works
Warm water pipework sits above the slab within the screed layer.
Hydronic in-screed heating circulates warm water through pipework installed on top of the structural slab and held in position before the screed is laid.
The water is heated by a central energy heat source, then distributed through designed loops below the finished floor. Because the pipework is closer to the floor surface than an in-slab system, it can provide a faster heating response while keeping the comfort quiet and concealed.
Benefits
Responsive floor heating above the structural slab.
In-screed hydronic heating is useful when a project needs radiant floor comfort with a shallower build-up and quicker response than a full in-slab system.
Application
Suited to tiles and selected floor finishes
In-screed systems are commonly considered for tiled areas, bathrooms, living zones and projects where the floor build-up can be coordinated early.
Comfort
Radiant warmth from beneath the finish
Warm water circulates through pipework below the finished floor, creating an even heat profile without visible wall emitters.
Retrofit
Useful for major renovations
Where the structural slab already exists, an in-screed approach can be assessed as part of a renovation or floor replacement scope.
Control
Thermostat and zoning flexibility
Zones can be designed around room use, floor finish, thermal load and the daily comfort pattern expected by occupants.
Heat source
Compatible with efficient hydronic plant
Correctly designed systems can work with air-to-water heat pumps, boilers, solar-assisted systems or geothermal plant where suitable.
Design and installation
Coordinated around the screed and floor finish.
The floor build-up, screed depth, pipe fixing, manifolds and finished floor material need to be coordinated before installation starts.
- 01
Check the build-up
We review slab levels, available screed depth, insulation, floor finishes and heat output needs.
- 02
Design the pipework
Pipe spacing, loops, zones and manifold locations are set around each room and finished floor area.
- 03
Install before screed
Pipework is fixed in place above the slab and coordinated with the screed installation sequence.
- 04
Connect and commission
The system is pressure tested, connected to the hydronic plant and commissioned with controls.
Technical planning
What needs to be resolved before screed works.
In-screed heating is highly dependent on floor levels, thermal transfer and installation sequencing. Early review helps avoid clashes with finished floor heights and other trades.
- Screed depth
- The available screed thickness must suit the pipework, fixing method, heat transfer requirements and finished floor levels.
- Floor finish
- Tiles and stone transfer heat well. Timber, vinyl and engineered products need compatibility checks against temperature and installation limits.
- Response time
- With less mass than a full slab system, in-screed heating can generally respond faster while still providing stable radiant warmth.
- Fixing and protection
- Pipework must be held securely during screed works and protected through pressure testing, floor preparation and final commissioning.
Suitable projects
Where in-screed heating makes sense.
- Major renovations with new floor build-up
- Bathrooms, kitchens and tiled living areas
- Architect-designed homes with finished floor coordination
- Projects needing faster response than in-slab heating
- New builds where the structural slab is already defined
- Hydronic systems using efficient central heat sources
FAQ
Common in-screed hydronic heating questions.
What is in-screed hydronic heating?
It is a hydronic underfloor heating system installed above the structural slab within a screed layer, rather than embedded inside the concrete slab itself.
How is it different from in-slab heating?
In-slab heating is installed within the concrete slab and has more thermal mass. In-screed heating sits closer to the floor finish, so it can usually respond faster.
Can it be used in renovations?
Yes, it can be considered for major renovations where the floor build-up, levels, screed depth and finished floor material can be planned properly.
Which floor finishes work best?
Tile and stone are common options because they transfer heat well. Other floor finishes need to be checked for compatibility with the heating output and manufacturer limits.
Projects
Projects using in-screed hydronic heating
Hydronic in-screed underfloor heating installed over 10mm Profi Duo boards across a South Bowenfels residence.
South Bowenfels, Central Tablelands, NSW
10mm Profi Duo Board Hydronic Underfloor Heating – South Bowenfels
Hydronic Underfloor Heating - In-Screed
A multi-zone hydronic underfloor heating system installed at a Bar Beach residence.
Bar Beach, Newcastle, NSW
Hydronic Heating System – Bar Beach
Hydronic Underfloor Heating - In-Screed
Hydronic in-screed underfloor heating using 10mm pipe installed across multiple zones of a Bronte residence.
Bronte, Eastern Suburbs, NSW
Hydronic In-Screed Underfloor Heating – Bronte
Hydronic Underfloor Heating - In-Screed
Plan the floor build-up
Check the screed depth before the system is locked in.
Share your floor build-up, finishes and project stage. SmartHeat can review whether in-screed hydronic heating is the right fit.
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Review SmartHeat's design, supply and installation service for complete project coordination.
Design, Supply & Installation