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In-screed/undertile heating

Our in-screed heating cables are suitable for your renovation needs as they can be laid on top of an existing floor before your floor coverings are laid.

In-screed/undertile heating cables

If you are planning to renovate an existing floor, Pyrotenax Electric Storage Floor Heating is the most economical, luxurious and practical form of space heating you can buy. 

During renovation, electric heating cables are secured to the light gauge mesh prior to the screed being laid. These cables heat the floor during regulated heating periods. 

How to install

Unlike traditional heating systems there are no ducts, fans, consoles or vents required. This frees up your wall and floor space giving you the freedom to decorate your interior without interferences.

Discuss it at your initial planning stage with your architect, builder or specialist heating installer.

In-screed cables intalled on existing concrete slab
Heating area

Measure your heating area

Using the examples below, measure the floor area you need to heat. 

Note: do not calculate permanent fixtures (wardrobes and benches) as heating areas.

Heating area

Living room example A

Heating area = 5.0m x 5.8m

                        = 29.0m²

Example A selection

Bedroom example B

Room area = 4.0m x 3.5m

                    = 14m²

Area of fixtures = 2m²


Heating area = 14m² - 2m²

                       = 12.0m²

Example B selection

Bathroom, toilet, laundry, hallway example C

Room area = 4.4m x 5.0m

                    = 22m²

Area of fixtures = 6.5m²
(bath, shower, toilet, bench)


Heating area = 22m² - 6.5m²

                       = 15.5m²

Example C selection

Cable sizes

Which heating cable size do I need?

After measuring your desired heating area, refer to the table to locate your suitable product (unit).


Floor coverings

Most types of floor coverings can be used, for example carpets (wool or synthetic), vinyl tiles, ceramic tiles and slate.

Bitumen backed carpet tiles are not suitable. 

Cork tile and parquetry must be laid on a dry floor. In other words, this must be laid after initial use of the heating system to evaporate the moisture remaining in the concrete floor.

Depending on the type of tile, a waterproof adhesive (such as a two-part latex adhesive) or mortar-bed fixing system must be used. Some adhesives (particularly the water based latex adhesives) will deteriorate and soften at temperatures above 40°C. The adhesive chosen should be capable of withstanding temperatures of up to 60°C without a loss of bond strength. 


Ceramic tiles



Laminate flooring

Marble flooring

Quartzite floor tiles


Stone tiles

Terracotta tiles

Travertine tiles

Vinyl flooring


Gentle background warmth

The heat stored inside the floor is emitted from the whole surface area, giving an almost even air temperature from floor to ceiling. Warmth is produced where it is required most, underfoot, and then radiates throughout the area. 

CSIRO tests show that where floor level temperatures are around 16°C people feel comfortably warm all over. When floor level temperatures are lower, people feel cold even if the temperature at head level is over 21°C. 

Pyrotenax Electric Storage Floor Heating is the energy - efficient way to provide a constantly comfortable room temperature. 

General Images 02_edited.jpg

Health and safety

The system is free from dirt, smoke or fumes. Any dust movement is minimal, so the system is ideal for people who suffer from respiratory difficulties such as asthma.


The system is safe for all family members as there are no burning surfaces

Burning surfaces

fire place

 Some other heating systems present hazards for children, the elderly or pets

Safety first

In-screed cables shown in floor

The system is securely encased in the floor and operates in silence

Economical and Energy efficient

Heat input to the floor is controlled by wall-mounted or in floor thermostats. Heating in each room or zone is controlled by a separate thermostat, so energy need never be wasted. 

The system takes advantage of low-cost off-peak electricity or time of use tariff available in most areas. When normal rate electricity is being used the system can be regulated by a time clock. Check with your local electricity authority regarding off-peak power availability in your area. 

The floor stores enough heat during the off-peak charge period to maintain a comfortable temperature for the full 24 hours. Heat storage is topped up again during the next heating period.

  • How does the system operate?
    Heat input to the slab is controlled by either a wall mounted air sensing thermostat or a wall mounted floor sensing thermostat. When the temperature reaches the thermostat setting the power supply automatically switches off and the stored energy heat continues to warm the room throughout the day. The heat is topped up again during the next regulated supply period.
  • What is electric storage floor heating (ESFH)?
    ESFH is a continuous space heating system. It consists of Pyrotenax electric heating element cast into the concrete slab floor of a house or building which then acts as a large radiant heating panel. The system is designed to operate on off-peak electricity, otherwise a time clock can be used.
  • How much does it cost to install?
    As a guide $70 per m2 for the average house. Delete any permanent fixtures e.g. kitchen cupboards or built in wardrobes. The cost covers supply of heating units, installation of heating units onto the reinforcing mesh and monitoring of the heating units during the concrete pour. The cost also covers the supply of all thermostats and controllers.
  • Are there any additional hidden costs?
    Costs not covered are: Wiring from the thermostat and heating unit to the switch board and connection to the off-peak supply. This work is usually done by the onsite electrician when all other lights and power points are wired.
  • What is the guarantee?
    The standard warranty of 10 years from the date of purchase applies to all slab heating elements manufactured by Pyrotenax. Thermostats are covered by a 2year warranty from the manufacture.
  • Who would you recommend installing the system?
    A specialist electric floor heating installer. Our technicians are trained to install all types of electrical floor heating. To learn how one of our technicians can help you, call (02) 9829 2752
  • What happens if something isn’t working – Can it be repaired?
    In the unlikely event of the heating element being damaged, it is a straight forward job to locate and repair the fault. We have equipment that can locate the cable and its fault. It is a simple matter of exposing the cable and fixing the repair.
  • What maintenance is required?
    Over the lifespan of the Pyrotenax system, minimal maintenance is required as there are no moving parts that wear and tear, apart from the thermostat which is a simple and easy replacement.
  • Is the system safe?
    Yes. The outer copper sheath of the Pyrotenax heating element is earthed during installation. Pyrotenax heating cables do not require to be connected to earth leakage protection.
  • Do you need to alter home/building design or make concrete slab thicker to accommodate heating cables?
    No. The heating cable is fixed to the reinforcing mesh within the standard slab design. Also, there is no need to allow space for ducting or furnace. There is no need to increase the slab thickness or change any structured reinforcing mesh.
  • What is off-peak electricity?
    Off-peak electricity supplied during the supply authority low demand hours. The electricity is supplied at a reduced cost. Price reductions are from 40 to 60% of the general rate cost. Floor heating may also be connected to a time of use tariff, a time clock is used to enable power only to be used in the low-cost hours.
  • Is off-peak much cheaper than normal electricity?
    Yes. Depending on the region it can be less than one third the cost, that’s over 50% savings.
  • How does off- peak electricity compare with gas running costs?
    Operating cost to maintain 21°C for 24 hours are generally cheaper than gas in most areas. The operating costs vary in some areas due to tariff charges and climatic conditions.
  • What about insulation?
    (a) A vapour barrier (polyethylene sheeting) beneath the slab is usually standard practice nowadays. (b) Certainly, ceiling insulation (batts) is recommended as 30-40% of heating can be lost through an uninsulated ceiling.
  • What is the minimum heated area in a slab floor?
    There is no minimum size, however, for 240 volt operation the heated area must be at least 2.0m².
  • What happens when a cold night is followed by a warm day?
    The heat will stay trapped in the slab when the air temperature exceeds the floor temperature so no heat will rise out of the slab.
  • How hot does the floor get?
    To maintain a 21°C air temperature the floor temperature would be approximately 25°C or approximately 4°C above the desired room air temperature.
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