The cooler months are on their way so I invited Luke Chant from Hotwire Heatings to chat to me about the ins and outs of underfloor heating. I have to admit that I have always shied away from underfloor heating because I was under the impression that it was quite expensive and not economical to run. I have discovered that is not necessarily the case.
In fact, using underfloor heating in your renovation is a nice little touch, especially in the bathroom. It adds a bit of luxury to your property. It is particularly appealing in areas such as Tasmania and Melbourne where it gets quite cold in winter.
What is Underfloor Heating?
The reason Luke’s company is called Hotwire Heating is because underfloor heating involves a hot wire that runs under the floor. The heated wire under the floor heats the house from the floor up. Luke explained:
The easiest picture that everyone would have in their head, that they would know, is the back window of your car. When you turn your demister on, you’ve got that little heating element that runs through the glass and defrosts it. That’s really what we’re doing with the floor.
Luke says that underfloor heating can be installed under all of the main three types of flooring: wood, carpet and tile. But tile conducts heat better than the other two and is therefore more effective. He notes that you should check the manufacturer’s specifications before installing underfloor heating though.
I asked Luke about the safety of installing underfloor heating under timber floors. He said that it is unlikely to catch fire, but it may warp if there is a lot of moisture in it. It is best to install it under products with a low moisture content.
I did a bit of research before chatting to Luke, so I had lots of questions for him. My first one was about heat pumps and hydronic heating:
- What is referred to as a heat pump varies depending on where you are in Australia. In Tasmania a heat pump is a reverse cycle air conditioner.
- Hydronic heating refers to hot water pipes that run under the floor. It is quite costly to install and Luke suggests that it is only a good option if you are heating a large area.
Is Electric Underfloor Heating Sufficient To Heat A Room?
Luke has used underfloor heating as the only form of heating in his home for some time now. He says:
As long as your house is well insulated, and well put together, then floor heating will heat the room quite nicely.
When you install underfloor heating in the bathroom there is no longer any need for a heat lamp. This is a great alternative that creates a much nicer warmth that will heat the whole bathroom.
The Cost Of Underfloor Heating
When Luke meets with a new client he asks this question:
What do you think it would cost to put floor heating in an average bathroom?
He says the answers are normally in the range of $2500 to $3000. He has had people think it could cost up to $10,000! He says it is a big misconception that underfloor heating is that expensive. In reality, the cost of installing underfloor heating in the average bathroom is around $1000.
The average running costs are also a lot less than you might think. A heat lamp runs at 1500 watts. The best system sold by Hotwire Heating runs at 600 watts – significantly more energy efficient than a heat lamp.
In terms of actual costs, after doing the calculations, Luke says that it will cost 2 cents per square metre per hour to run underfloor heating. Considering that the average bathroom floor is only four to five square metres, it would only cost you eight to ten cents per hour to heat your bathroom. You only need to run the heating for two to three hours per day, making your total daily cost just twenty four to thirty cents.
Underfloor heating is a much more cost effective way to heat your home than people might think.
Tips For Using Underfloor Heating
- Depending on the type of floor, underfloor heating can take thirty minutes to two hours to warm the floor. Tiles heat a lot more quickly than screed floors.
- Use the programmable thermostat. You can set your floor to come on an hour before you would normally use the bathroom, or any other room that you have underfloor heating in.
- Hotwire Heating has the option of a thermostat that uses your wifi system to connect to the Google Home or Amazon Alexa app on your phone.
Installing Underfloor Heating In The Bathroom
Legally underfloor heating needs to be installed by an electrician. It often happens that the tiler or the plumber on a job will install it and the electrician will sign off on it if he is happy that the work has been done correctly. Luke says that Hotwire Heating has a network of installers around Australia that are electricians.
If you are installing underfloor heating under a screed floor, the heating wires would be installed before the flooring. When it comes to waterproofing, it sometimes goes under the screed or over the screed. If there is no screed, you would have the floor, then the waterproofing and then the underfloor heating before finishing off with the flooring.
When we are doing a bathroom renovation we will ask the tiler what the final height of the floor will be so that the plumbing can be set at the right height. The wire for underfloor heating under tiles is 4 millimetres thick. Some tilers will set that into the tiling glue, but nother prefer to add a separate layer over the wire to make a flat surface which will add 4 millimetres to the height of the floor. For a screed floor the heating element is 8 millimetres thick, but it is surrounded by the screed and does not add any extra height to the floor.
One of the biggest advantages of installing underfloor heating in the bathroom is that when you heat the floor, you also dry the floor. It keeps your bathroom looking better for longer. Luke pointed out:
You don’t have to clean your bathroom as often because it’s not [going to get] mouldy. There’s none of that residue left over from water in the room. So you’re getting a nice warm bathroom, but you’re also getting a clean, healthier bathroom.
What Can Go Wrong With Underfloor Heating?
It’s an electric cable buried into your floor. There are obvious questions around that and the answers are already simple.
Luke shared these facts with me about the safety of underfloor heating:
- There are no safety concerns when it comes to water as the wire sits under a sealed surface. The water does not make contact with the wire.
- There is an alarm attached to the wires that will alert you if the wire is damaged in any way during installation.
- If the cable is damaged after installation, Hotwire Heating will use a thermal imaging camera that is put down the cable. It glows where the cable is damaged, so the wire can be repaired by removing just one tile.
- If you are concerned about the heating element cracking your tiles, rest assured that this is very unlikely. The wire only heats up to 40℃.
Some Interesting Applications For Underfloor Heating
To finish off my chat with Luke, I asked what are some of the more interesting requests he has had for underfloor heating installation. He said that one of the weirdest requests he’s ever had was to install underfloor heating in a piggery in Outback, Victoria. It was to keep the pregnant sows warm as they were nearing the end of the pregnancies. They have also installed heating systems in spas and prayer rooms.
My eyes have certainly been opened after talking to Luke about the ins and outs of underfloor heating. It is an effective and efficient way to heat your home and keep rooms like your bathroom dry and mould free for longer. If you would like to find out more you can visit the Hotwire Heating website.