ThermoSlab® Cable

Electric In-Floor Heating for Concrete

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  • Easily fits any space with loose cable designed for concrete installation
  • Provides between 12-18W/ft² of heat output depending on cable spacing
  • Factory attached 20 ft. cold lead wire for a flexible connection to thermostat
  • Systems compatible with 120/208/240 supply voltages
  • Complete system includes heating cables, in-floor sensors, and wall-mounted thermostat

Slab Heating Cable

Combine cables as needed to fit open walkable space, avoiding areas covered by cabinets, vanities or other permanent fixtures. The heating cable cannot be shortened, so avoid over-filling. Each cable will connect to the thermostat, so larger cables will reduce required connections. At 5" spacing on a sole thermostat, 120V cables cover up to 122 ft²; 240V cables cover up to 244 ft². DO NOT MIX VOLTAGES.Contact us for project assistance.

Cable spacing:
TS55-12023 ft²
TS85-12035.5 ft²
TS115-12048 ft²
TS145-12060.5 ft²
TS175-12073 ft²
TS200-12083.5 ft²
TS230-12096 ft²
TS290-120121 ft²
TS330-120137.5 ft²
TS375-120156.5 ft²

Thermostats & Critical Components

A floor heating thermostat is necessary to control your radiant heat system. Most of our floor heating thermostats are dual-voltage and include a 5ma GFCI, unlike models from online warehouse retailers. A thermostat is capable of a 15-amp load; adding a power module or relay will increase system load capacity. Each includes a floor sensor, but a backup is recommended. Select 1 thermostat for each zone desired. Contact an expert for guidance.

Learn more about UWG4-4999The OJ WiFi enabled touch screen thermostats are the latest, most cutting-edge option in heating controls.
Wi-Fi & Touch
Learn more about UWG5-4999OJ Smart Thermostats integrate with all home assistants and can be controlled easily from an app.
WiFi LED Touch
Learn more about UDG4-4999OJ Touch Screen thermostats have intuitive interfaces for stress-free operation and control of your heating systems in classic white color.
Touch Screen
Learn more about UDG4-4999-N4OJ Touch Screen thermostats have easy and intuitive interfaces for stress-free operation and control of your heating systems in the sleek black color.
Touch Screen - Black
Learn more about TH115-AF-GA/UAube Standard Programable thermostats allow for extensive programmability of 120- or 240-volt heating systems.
Learn more about UDG-4999OJ Advanced Programable thermostats allow for extensive programmability of heating systems and calendar scheduling.
Learn more about AC112-01/UA backup temperature sensor is recommended to be installed with the system in the event of a future sensor failure
Backup Sensor

Avoid future replacement headaches (15'). Include 1 per thermostat.

Learn more about IK-CONA thermostat installation kit makes installation of heating systems easy. Get everything you need in one simple kit and save time and money.
Mounting Kit

2-Gang electrical box, conduit & connectors. Include 1 per thermostat.


Electrical Accessories

Learn more about INSTALRMInstAlarm cable fault finder is recommended to ensure no damage is done to the heating element before, during, and after installation.

Monitor mats for faults during install

Learn more about MULTIMTRA digital multimeter is recommended to measure the heath of mats and cables during installation.

Verify resistance before/after install

Learn more about USG-4000The OJ power module is recommended when multiple mats exceed amp allowances and must be connected to a single thermostat.
OJ Power Module

Doubles the capacity of 1 thermostat


Tools & Kits

Learn more about IK-TAMMake your life easier, save time, and save money by getting the ThermoTile Advanced Kit which includes tools you will need for your installation such as an InstAlarm cable fault finder, plastic trowel, and digital multimeter.
Safe Install Kit

Save 15% over buying separately

Learn more about IK-TAMake your life easier, save time, and save money by getting the ThermoTile Basic Kit which includes tools you will need for your installation, such as an InstAlarm cable fault finder and plastic trowel.
Basic Install Kit

Save 9% over buying separately

Learn more about TRWL3838ThermoTile cable and mat installations require a plastic trowel for gentle mortar coverage over the heating elements.
3/8" Notch Trowel

Plastic trowel prevents accidental cable nicks

Learn more about TRWL3812ThermoSoft recommends a heavy-duty plastic trowel for gentle mortar coverage when installing ThermoTile cable and mats, so as not to nick or damage the heating element.
1/2" Notch Trowel

Plastic trowel prevents accidental cable nicks

Learn more about KNPD-318Installation of heating systems may be taxing on the installer’s knees. Avoid aches, pains, and damage to the heating mat with kneepads while protecting the heating element of your system.
Foam Kneepads

Protect the heat wires


How To Install ThermoSlab Heating Cable

Installation of floor heating with ThermoSlab cable is simple and easy.
This overview does not substitute for a full reading of the Installation Manual.

The below steps will take you from beginning to end simply, but please refer to the full Installation Guidelines or call us to go over a more detailed installation plan.

ThermoSlab Cable are an easy way to add heat to a concrete slab and is a great option for any basement, garage, or room addition. This system is most effective with tile, stone, or concrete flooring materials.

Before beginning your installation:

  • Plan your order for area coverage and desired watt density
  • Consider in your plan the need to stay 12 inches off from fixtures such as, but not limited to, drains, pipes, or electrical conduits.
  • Measure the resistance of the heating cables before beginning installation, as well as at multiple points during installation.
1Make sure you have the right amount of material
Step 1 of Installation of floor heating ThermoSlab cable is to make sure you have the right amount of material.
  • The cables should cover the entire floor space.
  • Follow heating cable spacing from walls according to the manual.
  • Heating elements should be in areas where you can walk, stand, or want to heat. See your manual for areas to avoid heating.
  • Contact support if you have any questions prior to your installation.
2Prepare conduits and electrical boxes for installation later.
Step 2 of installation of floor heating with ThermoSlab cable is to prepare conduits and electrical boxes for thermostat installation later.
  • Complete electrical rough-in
  • This step may be done after cable is laid but is more difficult to do later as location of thermostat may change location of heating system.
3Begin laying out the heating cable. Ensure that the cable will set at least 2 inches below the surface of the concrete.
Step 3 of installation of floor heating with ThermoSlab cable is to begin laying out the heating cable, ensuring that the cable will set at least 2 inches below the surface of the concrete.
  • Position the cable so that at least 12 inches of power lead wire will be embedded in the cement.
  • Follow the cable spacing intended in the plan established before ordering.
  • Many installers choose to attach ThermoSlab cable to the rebar or wire mesh, but cable strapping is another option.
4Install the sensors.
Step 4 of installation of floor heating with ThermoSlab cable is to install the sensors.
  • Highly recommended to install a backup sensor.
  • Position sensor evenly between 2 heating cables.
  • Do not cross the heating cable.
5Pour the concrete
Step 5 of installation of floor heating with ThermoSlab cable is to pour the concrete.
  • Ensure that all persons involved in the pour take necessary care to not damage the cable with tools or machinery.
  • Test the resistance of all cables while concrete is still wet.
6Wait until the concrete is fully cured before powering on the system.
Step 6 of installation of floor heating with ThermoSlab cable is to wait until the concrete is fully cured before powering on the system.
  • This is roughly a 30 day process, consult with the specifications of the concrete for a specific length of time.

ThermoSlab Cable Documents

ThermoSlab Cable FAQ

What is ThermoSlab?
ThermoSlab is a system of rugged heating cables tough enough to be installed directly in a new concrete foundation, or in the sand beneath a slab. ThermoSlab gives you the most permanent access to radiant heat as it survives any remodel, and even allows heat storage due to concrete slowly releasing heat over a longer period compared with typical floor coverings.Shop Now
Is this a safe product to put in my home or business? What about EMF?
Yes. All our floor heating solutions endure rigorous development and quality control testing to ensure that your floor heating system is reliable and safe. Due to the shielding and dual cable design used in ThermoSoft products, our radiant heat systems add virtually zero EMF. Shop Now
Can I use ThermoSlab with my floor material?
ThermoSlab is installed directly in your foundation slab concrete, so any floor covering that can be installed over a concrete slab can be installed over ThermoSlab.Shop Now
How do I install ThermoSlab? How do the cables get connected?
ThermoSlab is arranged before pouring your concrete slab and can be attached to mesh or rebar if you are using those materials to make arrangement of the cables easier. Make sure to read the full Installation Manual before beginning! ThermoSlab cables are wired to a floor heating thermostat in parallel. The number of cables and layout of the room will affect the exact process of how to wire the heating cables together. Please see the Installation Manual for explicit directions, or contact our in house experts for assistance. Shop Now
Will this add height to my floor?
No, the ThermoSlab cable will be embedded in the concrete and will not add height in any way.Shop Now
How deep does the concrete need to be for ThermoSlab?
ThermoSlab can be installed in concrete that is 2 inches or thicker.Shop Now
What if I’m not pouring a full 2 inches of new concrete?
If you are pouring concrete at less than 2 inches, ThermoTile Mats will be a better fit. Not sure how to proceed? Give us a call and our experts will gladly help!Shop Now
Can I combine more than one ThermoSlab cable to fit a space?
Many projects involve using more than one cable, but this means that multiple cables are wired in parallel to the thermostat. The thing to remember is that you are not daisy-chaining or extending the heating cables, but rather the cables are working together to cover the appropriate square footage by connecting them in parallel to the floor heating thermostat.Shop Now
Can I cut or shorten the heating cable?
No. We do not warranty the cable when the heating element has been cut. Call us in advance and our floor heating experts will be able to match your project with the correct length of heating cable and advise on how to properly lay it out.Shop Now
Can I shorten the lead wires?
Yes. The lead wires, also known as cold leads because they do not produce heat, can be cut, shortened, or spliced with additional cold lead cable to lengthen them.Shop Now
What do I do with areas that are not heated?
Floor covering is installed as normal over the heated and non heated areas of the slab.Shop Now
Can ThermoSlab cable really stand up to pouring a new slab?
Yes! ThermoSlab is a rugged and durable cable that we recommend specifically for this type of application. We also highly recommend using one of our InstAlarm Monitors during installation. The InstAlarm Monitor is a device that connects to the lead wires and will produce a loud sound if there is damage to the heating cable.Shop Now
How many watts per square foot does ThermoSlab output?
This figure can vary if the cable spacing deviates from the 5 inches on center spacing, but the standard output of ThermoSlab is about 14 watts per square foot.Shop Now
How much will it cost to run this system?
The cost to operate is a complicated question to answer, as electrical rates vary by area, your home's insulation, and even by time of day. Additionally, a cost-to-operate is further complicated because the money spent on your radiant heat can result in a net savings on total utilities cost due to reduced use of your traditional HVAC, which is added to by the fact that you will spend less on HVAC system maintenance by relying on electric radiant heat.Shop Now
How hot does ThermoSlab get?
Sometimes, we like to answer a question with a follow-up question. Usually, we are asked about “how hot” a system gets for a couple of reasons, so it is important to understand whyo you ask? Are you concerned about providing enough heat to adequately warm your space? If so, a properly installed ThermoSlab can provide about 10-15 degrees Fahrenheit of temperature difference above the ambient temperature of the room. In practice, this is more than enough, even in extremely cold climates. We are positive that you will be entirely satisfied with the heat produced by ThermoSlab. Are you concerned about applying too much heat to your chosen floor material? If so, fear not! ThermoSlab is designed to apply heat gently and evenly, due to the nature of the heating elements and the cable spacing pattern that it features. Additionally, ThermoSlab sits in concrete, which allows the heat to disperse warmth gradually and evenly. Depending on the floor covering you use, you may want to control your heat a little differently. Certain floor coverings are more temperature and temperature-change sensitive. Call us to have an our in-house experts go over some of these radiant heat “best practices.” Lastly, we highly recommend choosing a thermostat that includes a temperature limiter if this is one of your concerns!Shop Now
How long will ThermoSlab last? How long is the warranty?
ThermoSlab has no moving parts and therefore it does not require regular maintenance once installed correctly and if left undisturbed (remember your radiant system is down there when planning a remodel!). The heating cables are warrantied for 10 years, but after multiple decades on the market, we have yet to see a system fail due to old age. The thermostats that we offer are warrantied for 3 years because we only use thermostats with GFCI protection which, per national electric code, is recommended to be replaced every 3 years. Replacing a thermostat is simple, easy, and inexpensive.Shop Now
I’m still confused.
Then call us, email us, or message us through our website our floor heating experts will be happy to assist you!Shop Now

Features of ThermoSlab Cable:

  • Factory-attached 20' lead wires
  • UL Listed in the U.S. and Canada
  • Zero EMF
  • Floor heating adds comfort and property values
  • Tough to withstand installation
  • Smart when combined with a WiFi thermostat
  • 10-year warranty against manufacturing defects

Our Commitment to You

ThermoSoft technical support is available with live electric radiant heating experts. They are ready to take your call now! Call (800)308-8057 for more information or help with your in-floor heating, snow melting, bathtub heating, or soil heating project.
Supported by Real People

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ThermoSoft is the best partner for your project because we know when to listen, and when to offer guidance.

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