In-Screed Underfloor Heating Guide (Electric Systems for Concrete Floors)
In-Screed Underfloor Heating Guide UK
Electric underfloor heating in screed for new builds, extensions and long-term whole-floor comfort.
In-screed underfloor heating is an electric heating system designed to be installed within a new screed floor build-up. Instead of sitting directly below the floor finish, the heating cable is laid over insulation and then covered with screed, allowing heat to spread gradually and evenly through the floor structure.
This makes electric underfloor heating in screed especially suitable for new builds, extensions and major renovation projects where a new floor is being formed from scratch. It is a durable option for buyers who want a more permanent heated floor build-up in kitchens, bathrooms, living spaces and larger open-plan areas.
If you are still deciding whether a buried screed system is the right option, our Electric Underfloor Heating Guide and Best Electric Underfloor Heating Systems Buyer Guide help compare in-screed heating with DCM-PRO, StickyMat & EcoFloor Heating Mats Guide UK, loose wire, foil heating and EcoFilm carbon film systems.
Quick Links
Electric Underfloor Heating Installation Guide
Underfloor Heating Thermostats Guide
Underfloor Heating Insulation Guide
Foil Underfloor Heating Guide
Carbon Film Guide
In-Screed Running Costs Guide
What Is In-Screed Underfloor Heating?
An in-screed heating cable is designed to become part of the floor structure itself. The cable is positioned over insulation, fixed in place, and then embedded within the screed. Once the screed cures, the floor acts as a large thermal mass, releasing gentle radiant heat across the room.
That makes electric underfloor heating in concrete floors or screed floors quite different from systems such as Warmup StickyMat, Flexel EcoFloor heating mats or loose wire, which are usually installed closer to the floor finish. In-screed systems warm up more slowly, but they provide very even and stable heat once the floor is up to temperature.
For buyers comparing systems, this is one of the key differences: screed systems are usually chosen for steady whole-room heating, while tile-surface systems are often chosen for faster response closer to the finished floor.
In-screed systems are typically laid over insulation and covered with at least 50mm of sand and cement screed. The heating cable must not be cut or crossed, and final electrical connection must always be completed by a qualified electrician.
If you are building a new floor from scratch and want a durable, hidden heating system beneath the screed, in-screed heating is often one of the best electric options to consider.
Recommended In-Screed Heating Products
A single-core 15W per linear metre heating cable supplied on a drum for new-build screed floor installations.
An electric heating cable system designed to be buried within screed for long-term whole-floor warmth.
A strong thermostat option for in-screed systems where scheduling and stable floor control are important.
How Ecofloor and Warmup In-Screed Systems Work
Ecofloor In-Screed Underfloor Heating Cable is Flexel’s in-screed solution. It is a single-core, 15W per linear metre electrical heating cable designed for new-build screed floors. It is laid on insulation, covered with at least 50mm of sand and cement screed, and is intended as an economical way to warm floors in kitchens, bathrooms and living areas.
The cable is supplied on a drum for professional installation and must not be cut or crossed. Like other electric underfloor heating in screed systems, it becomes part of the floor structure once the screed is poured and cured.
The Warmup In-Screed system follows the same overall principle: the heating cable is positioned within the build-up before screeding, allowing the floor mass above to store and release heat evenly over time.
If running costs are one of your main concerns, it is also worth reading our In-Screed Running Costs Guide, which explains how insulation, room size and thermostat settings affect real electricity use.
Typical In-Screed Installation Overview
The floor structure must be ready for a new screed build-up and suitable for insulation and cable installation.
Insulation is installed first to reduce downward heat loss and improve the efficiency of the whole system.
The heating cable is fixed in place over the insulated base and spaced correctly across the floor area.
The cable is embedded beneath at least 50mm of screed, creating a stable, permanent heated floor structure.
In-Screed Underfloor Heating Running Cost Context
In-screed electric heating is often judged unfairly by maximum-output figures alone. In reality, the running cost depends on the heated floor area, the wattage installed, how much insulation sits below the system, and how intelligently the thermostat schedules the heat.
Because the screed acts as a thermal mass, in-screed systems usually take longer to warm up than StickyMat & EcoFloor heating mats or loose wire systems, but they can hold warmth for longer too. That makes them attractive in larger rooms or new-build layouts where steady comfort matters more than ultra-fast response.
| What Affects Running Costs? | Why It Matters |
|---|---|
| Insulation below the screed | Reduces downward heat loss and usually makes the biggest difference to efficiency. |
| Thermostat scheduling | Helps the floor heat when needed rather than running for longer than necessary. |
| Heated area only | You normally heat usable floor area, not every square metre under fixed furniture or units. |
| Floor finish above | Tiles and stone usually transfer heat differently from timber or softer floor coverings. |
For room examples, cost-per-hour guidance and a buyer-friendly cost breakdown, see the In-Screed Running Costs Guide.
When In-Screed Underfloor Heating Is the Best Choice
Best For These Projects
- New build homes where a full screed floor is already planned
- Extensions where a new concrete or sand-cement screed floor is being formed
- Large open-plan rooms needing stable, even radiant heat
- Projects where heating must be completely hidden within the floor build-up
- Buyers who want long-term low-maintenance electric floor heating
If you want faster warm-up closer to the finished floor rather than slower, steadier thermal-mass heating, systems such as DCM-PRO, loose wire or StickyMat & EcoFloor heating mats may be more suitable.
Is In-Screed Electric Underfloor Heating Worth It?
For new builds and extensions where a new screed floor is already planned, in-screed electric heating is often one of the most durable and stable heating options available. Because the heating cable is embedded within the floor structure, the screed acts as a thermal mass that distributes warmth evenly across the room.
Compared with thin systems installed directly beneath tiles, in-screed heating usually warms up more slowly but maintains heat for longer. This makes it particularly effective in larger rooms where stable background heating is preferred over rapid temperature changes.
Why Insulation Matters for In-Screed Heating
Insulation is one of the most important parts of an in-screed underfloor heating installation. Without it, a large amount of heat can be lost downward into the structural slab rather than rising into the room.
That is why both buyers and installers usually treat insulation as a core part of the build-up rather than an optional extra. It helps improve warm-up time, reduces wasted energy and makes the system much more effective in everyday use.
For most projects, the thickness of insulation depends on the build-up available and whether the floor is part of a renovation or a new build. In renovations where height is limited, slimmer boards may be used. In new builds where maximum efficiency matters, much thicker insulation is often the better choice.
- Renovations with limited height: lower-profile insulation such as 6mm or 10mm boards can help reduce floor build-up.
- New builds and maximum efficiency: thicker insulation is usually the better option because it reduces heat loss and helps lower long-term running costs.
Insulation beneath in-screed heating can help:
- reduce downward heat loss
- improve energy efficiency
- make the system more responsive
- push more heat toward the floor surface
Because insulation has such a big effect on both performance and running costs, it is worth reading the Underfloor Heating Insulation Boards Buyer’s Guide before finalising your floor build-up.
Designed to improve electric underfloor heating efficiency by reducing heat loss into the subfloor.
A useful insulation option for improving electric floor heating performance and reducing wasted heat.
Learn how insulation improves heating efficiency, performance and running costs across electric floor heating systems.
Thermostats for In-Screed Underfloor Heating
A thermostat with a floor sensor is essential for electric underfloor heating in screed. Because screed stores heat and releases it gradually, accurate thermostat control is important for comfort, efficiency and preventing unnecessary running time.
In practice, in-screed systems usually benefit from programmable or smart thermostats because the floor warms up more slowly than a mat or loose cable system installed closer to the surface. That means timing and temperature control matter even more.
If you are unsure which control to use, our Underfloor Heating Thermostats Guide explains which smart and programmable thermostats are best for electric floor heating systems, including slower-response screed floors.
A strong all-round option for in-screed heating where scheduling and stable long-term control are important.
A premium thermostat with smart control, app access and better scheduling options for energy-aware buyers.
Compare the best thermostat options for electric floor heating systems, including screed, tile and floating floor build-ups.
In-screed systems are usually best paired with a smart or programmable thermostat because the floor takes longer to warm up and cool down than surface-mounted electric systems.
In-Screed Heating vs Other Electric Underfloor Heating Systems
| System | Best For | Main Advantage | Typical Build-Up Style |
|---|---|---|---|
| In-Screed Heating | New builds, extensions, new floor structures | Even heating through thermal mass | Cable embedded in screed |
| DCM-PRO | Tiled floors needing movement protection | Decoupling + heating | Membrane + cable |
| StickyMat & EcoFloor Heating Mats | Bathrooms and regular-shaped tiled rooms | Fast installation and tidy pre-spaced cable layout | Heating mat below tiles |
| Loose Wire | Irregular tiled rooms | Flexible layouts | Loose cable below tiles |
| Foil Heating | Laminate, engineered wood, some floating floors | Low build height | Dry system below floor finish |
| EcoFilm Carbon Film | Floating laminate and engineered wood floors | Wide, even coverage beneath suitable floating floors | Dry film heating system |
If your floor is being newly screeded, an in-screed cable is often the most natural electric solution. If you are working closer to the finished floor level instead, systems like DCM-PRO, loose wire, foil heating or EcoFilm carbon film may be more suitable depending on the floor finish.
For tiled floors in particular, it is worth comparing in-screed heating with both Warmup StickyMat and Flexel EcoFloor heating mats via our StickyMat & EcoFloor Heating Mats Guide UK. Heating mats usually respond faster because they sit much closer to the finished tile layer.
If you want faster heat-up closer to the finished floor rather than the slower, more stable warmth of screed heating, compare our Heating Mats Running Costs Guide, Loose Wire Running Costs Guide and DCM-PRO Running Costs Guide. If your floor finish will be laminate or engineered wood instead, see our Foil Running Costs Guide and Carbon Film Running Costs Guide.
Practical Installation Advice Before You Order
- Confirm the finished floor build-up and available floor depth before selecting cable size.
- Plan insulation properly because it has a major effect on efficiency and long-term running costs.
- Measure only the usable heated area and exclude fixed units, sanitaryware and permanent furniture.
- Allow the screed to cure fully before first heat-up.
- Choose a thermostat suited to slower-response screed systems, ideally with smart scheduling and floor sensing.
For full build-up help, subfloor advice and installation sequencing, see our Electric Underfloor Heating Installation Guide.
Who Should Choose In-Screed Underfloor Heating?
- Buyers building a new screed floor
- Extensions and new-build projects
- Large rooms where stable whole-floor warmth is preferred
- Projects where a hidden heating system inside the floor structure is ideal
- Anyone wanting a more permanent electric underfloor heating in screed build-up
Frequently Asked Questions
What is in-screed underfloor heating?
In-screed underfloor heating is an electric heating cable system installed within a screed floor build-up. The cable is laid over insulation and then covered with screed so the floor itself becomes the heated mass.
Is Ecofloor the Flexel in-screed system?
Yes. Ecofloor In-Screed Underfloor Heating Cable is Flexel’s in-screed electric heating cable, designed for new-build screed floors and supplied on a drum for professional installation.
Do I need insulation with in-screed heating?
Yes. Insulation is strongly recommended because it reduces downward heat loss, improves efficiency and helps more heat rise into the room.
What thermostat is best for in-screed underfloor heating?
A thermostat with a floor sensor is recommended, and a smart or programmable model is often the best choice because screed systems respond more slowly than surface-mounted heating systems.
Can I use in-screed heating in bathrooms and kitchens?
Yes. In-screed systems can be used in bathrooms, kitchens and living areas, especially where a new screed floor is being installed as part of the project.
Can the in-screed heating cable be cut?
No. The cable must not be cut or crossed. The correct cable size should be chosen for the heated area and installed according to the manufacturer’s instructions.
What is the minimum screed depth required?
Both Warmup and Flexel systems typically require at least 50mm of screed. For many in-screed systems, the cable should also have adequate screed cover above it to protect the cable and allow even heat distribution.
Which floor finishes can I use above in-screed heating?
Once embedded in screed, these systems can be used beneath tile, stone, laminate, engineered wood and some carpet or vinyl floor finishes, provided the final floor covering is suitable for underfloor heating.
How long does the floor take to warm up?
In-screed systems normally warm up more slowly than thin electric mat or loose cable systems installed nearer the floor finish. However, once the screed is warm, it stores heat well and releases it steadily.
How long should I wait before switching the heating on?
You should wait until the screed has fully cured before switching the heating on. Turning it on too early can risk damage to the floor build-up.
Is in-screed better than StickyMat or EcoFloor heating mats?
It depends on the project. In-screed heating is usually better for new screed floors and steady long-term whole-room heating, while StickyMat and Flexel EcoFloor heating mats are usually better when you want a faster-response tiled-floor system closer to the finished surface.
Is in-screed electric heating expensive to run?
Not necessarily. Running costs depend more on insulation, thermostat control, heated area and room heat loss than on the system type alone. Well-insulated screed floors with sensible scheduling can perform very efficiently.
Can in-screed heating work as the main heat source?
Yes, in many well-insulated rooms it can act as the main heating source. Whether it is suitable as primary heat depends on room heat loss, build-up and the output selected.
Compare Electric Underfloor Heating Systems
In-Screed Running Costs Guide
Loose Wire Guide
Loose Wire Running Costs Guide
DCM-PRO Guide
DCM-PRO Running Costs Guide
StickyMat & EcoFloor Heating Mats Guide UK
Heating Mats Running Costs Guide
Foil Underfloor Heating Guide
Foil Running Costs Guide
Carbon Film Guide
Carbon Film Running Costs Guide
Ready to Buy In-Screed Underfloor Heating?
If you are installing a new screed floor and want a durable electric heating system, these products are commonly used in UK projects:
You can also explore our full electric underfloor heating systems collection guide to compare all available system types.
Ready to buy? Start with the Warmup In-Screed Underfloor Heating System or Flexel Ecofloor In-Screed Cable, then pair it with the right insulation build-up and a suitable smart thermostat for better efficiency and control.