Sunrise Specialty » How to Install In-Floor Heating for your Bathroom? (Step-by-Step Tutorial)

How to Install In-Floor Heating for your Bathroom? (Step-by-Step Tutorial)

Having a heated floor might sound like an expensive luxury that you think is out of your budget, but the cost of installing them is coming down all the time.

Furthermore, you can even do most of the work yourself – so here’s how to install in-floor heating for your bathroom for anyone who wants to try.

If you’re looking for a preview of some of the stuff we’re going to be talking about – as well as some extra tips and tricks – you can check you this video before reading on.

What are the different types of in-floor heating?

Before we talk about how to install in-floor heating, we need to mention something about the different options that are available since there are a couple of possibilities.

There are basically two types of in-floor heating found in homes, electric and hydronic. The electric version works by heating coils beneath the floor using electricity, like a heated jacket, while hydronic systems involving using hot water.

Hydronic systems have certain advantages over electric systems, especially if you already have a boiler in your home, namely that they can be more efficient and cheaper to run.

However, they are not easy to install as a DIY project, and if you want a hydronic system built into your home, you are better off hiring a professional to do the work.

For this reason, in this guide, we are going to concentrate on how to install an electric version since they are easier to fit and something that more people are likely to be able to attempt themselves.

Tools and materials required

  • Glue gun
  • Trowel
  • Utility knife
  • Volt-ohm meter
  • Cement board underlay
  • Cement board screws
  • Mesh fiberglass tape
  • Grout
  • Radiant heat mat
  • Thermostat
  • Thin-set mortar
  • Tile or other floor surface

Step-by-step guide for Installing In-Floor Heating

Once you have assembled your tools and materials, here are the steps you need to follow to complete the job.

Step 1. Measure the space you plan to heat

Measure the space you plan to heat

Before you can buy the heat mat needed for the project, you will need to start by measuring the area you wish to install it in. When you have worked out how much will be required, you can buy the mat for the project.

Pro tip: When your mat arrives, you need to test if for defects and to make sure it is functioning correctly – since it will be no good if you discover issues only after you have laid the floor!

You can do this using a volt-ohm meter, an inexpensive item that will allow you to compare the mat’s resistance with the stated mat resistance in the instruction manual. These numbers should be within about 15% of each other.

Step 2. Plan how it will be powered

Before you start working, you also need to consider how the mat will be powered. For smaller areas, for example, less than 20 sq. ft., you can use a GFCI-protected outlet. You can also buy a thermostat that is GFCI-protected, which will allow you to use any regular outlet.

However, for larger mats exceeding 20 sq. ft., you will need to install a separate circuit with a circuit-breaker to avoid tripping the circuit when you use the heating and other electrical items at the same time.

At this point, you should also decide where you are going to place the thermostat.

Pro tip: Even the most skilled DIYers might not have the necessary skills for the electrical part of the project. If you’re not sure about electrical work, you can hire an electrician for this part and simply take care of the rest yourself.

Step 3. Lay the cement board

Lay the cement board

Assuming you have prepared the area of floor where you are going to install the heating mat and stripped away everything down to the subfloor, you should now lay the cement board over the area where the heating mat is going to be laid.

First spread a layer of thin-set mortar over the area and lay the cement board on top, fixing it in place with the cement board screws.

Pro tip: You can tape over the joints with the mesh fiberglass tape to create a seal and to make sure everything is held firmly in place.

Step 4. Lay out the mat

Lay out the mat

Roll out the mat and lay it in place to check that it fits as required. Unroll the mat and lay it out from one end to the other. You will then need to cut the mesh to turn it around and run it back in the other direction – but be sure not to cut the power cable at the same time.

Repeat until you have laid out the matt evenly of the whole area that you want to be heated. When you are sure that everything is in the right position, you can glue and tape the mat into place so it won’t move.

Pro tip: Before laying out the mat, make sure the floor is clean and clear of any debris. Also, make sure that no cement board screws are sticking up out of the floor. You want to make sure there is nothing there that can damage the cable.

Step 5. Position the floor sensor

Position the floor sensor

Not all brands of heating mat have a floor sensor, but if yours does, position it now. Choose somewhere close to where the thermostat will go and place it in between two heating elements.

Pro tip: Fix the sensor in place either by weaving it into the mesh or by using hot glue.

Step 6. Run the thermostat wires to where the thermostat will be connected.

Run the thermostat wires to where the thermostat will be connected.

Before you tile the floor, you need to make sure all the necessary wires will be accessible for the electrical work at the end. Run the thermostat wire and the power cord to the wall where they will be connected to the thermostat.

Step 7. Tile the floor

Tile the floor

When everything else is in place, you can now lay the tiles. Start by spreading a layer of thin-set cement over the top of the heating coils and mesh and then lay the tiles.

When the tiles are all in place and you are satisfied that the floor is perfectly even, leave them until the thin-set has completely dried. After this, you can come back and grout the joints and wait for this to set too.

Pro tip: When choosing your tiles, with heated floors, it is better to choose larger tiles since smaller ones are likely to show imperfections more due to the cable and mesh underneath them. With larger tiles, this will be less of a problem.

Pro tip: Other than the size, you don’t need to worry about buying any special type of tiles for use in heated floors since most will be suitable. However, when choosing the tiles, you should check the manufacturer’s notes to see if they are specifically not suitable for this application.

Step 8. Fit the thermostat

Fit the thermostat

Having fit the tiles, you are now ready for the final electrical work required to complete the project. As we mentioned earlier, this might be beyond the capabilities of some home DIYers, so if you’re not sure, it might be a better idea to consult a professional electrician.

However, the thermostat should come with instructions, so if you feel confident, you can also try to do this step yourself. If you do, above all, make sure the power is switched off before you start working with the wires.

Step 9. Test the heated floor

Test the heated floor

When everything is in place, all that remains is to test your work. Switch on the heated floor and wait for around ten minutes to see if everything is working as it should.

If your floor heats up, you have successfully completed the project and you are now the proud owner of a cozy heated bathroom floor!

Extra tips for Installing In-Floor Heating

Here are a couple of extra pro tips that will help you complete this project successfully.

Choose a different floor for the heated area

You can choose to heat a certain section of the floor only and then cover the whole floor in the same tiles. However, it is better to choose a different type of floor for the heated area, for example, a different type of tile.

This can create an attractive visual effect, but the main reason is that if something goes wrong, you will only have to tear up the section of floor that is heated rather than having to destroy the floor for the whole bathroom.

Tile or stone floors are best

When it comes to heated floors, the kind of materials commonly used in bathrooms are the best. Tile or stone floors conduct the heat perfectly, so when you step onto it barefoot in the middle of the night, it will be comfortably warm instead of unpleasantly cold.

A challenging but achievable project

It has to be said that installing a heated bathroom floor is not a project for DIY novices. However, if you have a certain level of DIY expertise, it is a rewarding project that will leave you with a luxurious heated floor – and save you some cash at the same time too.