So it’s time for a bathroom remodel and you are wondering if installing underfloor heating is worth the extra cost and hassle.
There are many things in life that are great to have, but not essential. Underfloor heating in a bathroom is one of them. Life is perfectly OK without it, but there is nothing like the feeling of cozy warm tiles under your feet in the morning.
If you value comfort, energy efficiency and safety then bathroom underfloor heating will be worth it to you. Adding it during a remodel does not add significantly to the cost.
If you happen to live in a region where winter temperatures mean frozen lakes and winter tire, then you are probably used to ice-cold tiles in the bathroom. UFH (underfloor heating) will make the bathroom your favorite place in the whole house during chilly December days.
Depending on how you heat your house, it will most likely end up saving you money in the long run.
There are two types of underfloor heating systems; wet and dry systems. A wet system circulates hot water through pipes that are laid under the tiles. A dry system heats up the floor by heating up wires that are placed under the tiles.
There are countless benefits to under-floor heating, all buildings would use this kind of system if cost were no issue. In Europe, the majority of new buildings use underfloor heating. The high level of comfort and long-term energy savings make it a popular choice.
Let’s take a look at all the benefits of underfloor heating in a bathroom.
Note: I have recently installed underfloor heating in my entire house, so everything I write is from personal experience.
Increased Comfort Level
A bathroom can be heated by various means some, not all of the options are –
- Underfloor Heating
- Heated Bathroom Fan
- Forced Air Furnace
- Baseboard heater
Underfloor heating provides the highest level of comfort compared to other types in this list. The floor will be relatively cold with other means of heating. When walking barefoot, as one often does in a bathroom this is especially uncomfortable.
With every other heating system floors will be the coldest surface of the room. If you would like to increase the floor temperature you have to keep the entire room at a much higher temperature. This will waste energy and still, it won’t be as good as underfloor heating.
The cold floor problem is most noticeable in bathrooms. The floors in bathrooms are often tiled and tiles have good thermal conductivity. This means that they will easily absorb heat. In this case, it is your feet where the heat is coming from. The higher the thermal conductivity the colder the surface will feel.
There are two ways to make the floor feel warmer under your feet.
- Heat the floor
- Use a floor covering with low thermal conductivity
This is where we run into a problem. All materials that are suitable for use in the wet bathroom environment have relatively high thermal conductivity. A carpet is an example of a material with low thermal conductivity obviously a carpet is not suitable for use in a bathroom 🙂
This means in a bathroom there is only one way to make the floor feel warm and comfortable. That is to use underfloor heating.
I must warn you though… There is one “serious” drawback to installing underfloor heating in your bathroom. Your feet will get used to the nice and warm floors. Showering at a friends place will make you miss your own warm bathroom 🙂
Protection From Mold and Mildew
Radiators, baseboard heaters and baseboard heaters concentrate the heat in one place. Often there is only one radiator placed on one side of the room. This means that the temperature will be considerably lower at the other end of the room.
Lower temperature means that the moisture in the air will condensate on the surfaces that are far away from the heat source. If the ventilation is insufficient and the water stays on the surfaces for an extended period of time, there is a high chance that mold and mildew can start to grow.
Underfloor heating keeps the floor at a constantly high temperature. Since almost* the entire floor is warm, there will be no chance for moisture to condensate in a cold corner of the bathroom.
*heating cables/pipes are generally not placed under cabinets, bathtubs and toilet bowls
Underfloor heating will dry out the entire bathroom much faster, this will make it very hard for mold and mildew to grow.
While underfloor heating will greatly help reduce the risk for mold and mildew, ventilation of the bathroom is still very important. The moist air must still be exhausted out of the house.
I assume you are reading this because you are planning a bathroom remodel. If so make sure that you do not forget the ventilation. I have composed a comprehensive guide to choosing the correct bathroom fan. This guide will make it very easy to choose a fan.
When comparing underfloor heating with a radiator it can save up to 15% of the energy costs. The majority of the savings come from lower room temperature and lower energy losses thanks to the lower temperature of the floor compared to the radiator.
Lower Room Temperature With Same Perceived Temperature
Since the entire floor is heated it is possible to slightly lower the room temperature without noticing a difference. Even when the temperature is lower when measured, the perceived temperature will be the same.
Since the floor will radiate heat towards people, a lower indoor temperature will feel warmer. I’m sure you know the feeling of heat radiating from a campfire, even when the outdoor temperature is cold you will feel warm when the heat is radiated towards you. On average it is possible to lower the indoor temperature by 2-5 °F when using a radiant underfloor heating system, compared to radiators and forced-air heating.
Lower Heat Source Temperature
Underfloor heating does not create any hot spots. This means that the energy losses will be much smaller compared to radiators. The heat loss from a radiator that is placed on an exterior wall will be significant. The temperature at the back of the radiator will be very high, the higher the temperature difference, the more energy is lost.
The heated floor temperature will be considerably lower compared to radiator temperature. This will transfer less heat, and in turn will save energy.
For wet systems that are connected to a heat pump, the savings are even greater. The efficiency of a heat pump decreases when the output water temperature is increased. Since the heating area of radiators is drastically smaller compared to underfloor heating, the water temperature must be much higher to be able to heat the room.
- The average radiator water temperature is 150°F
- Average underfloor heating system temperature: 95°F
Modern Underfloor Heating Is Extremely Easy To Install
If your bathroom is going to be re-tiled anyway, adding underfloor heating will add very little extra work. This is of course if you choose a heating mat, not the loose wire. I recommend Heatwave underfloor heating system (amazon link), they have a 20-year warranty which is very important for something that is placed under tiles.
Note : The warranty is valid only when the electrical connection is made by a qualified electrician.
It took me 45 minutes to lay the heating mat in a 40 sq ft bathroom. After that, it was the same amount of work to tile the floor, as without the mat. If you pay someone to do it, make sure that they don’t rip you off. It should not take more than an hour extra to lay the heating mat. The amount of time it takes to make the electrical connection depends on whether the wiring is available in the bathroom or not.
Bathroom Will Dry Faster
A heated floor will dry out the entire bathroom much quicker. Without a underfloor heating the floor of the bathroom could be still wet from a shower after a couple of hours. With a warm floor, it will be dry in about 30 minutes.
This is great news for people who don’t want to dry the bathroom floor after taking a shower. The warm floor will take care of if for you.
You can also leave small bathroom rugs on the floor without the risk of them being damp and moldy. The floor will get very warm under the rug and there is absolutely no chance that it will ever be damp.
Note: From an energy-saving perspective it is not good to have rugs on floors that are heated. This will increase the floor temperature and more of the heat is transferred down into the floor construction, instead of the bathroom.
More Space In a Tiny Room
Bathrooms are often very cramped, and every square inch is valuable. By eliminating radiators you can free up an entire wall for other purposes. Even baseboard heaters and forced air vents take up space since it is not possible to place anything in front of them.
However, with underfloor heating, all the wall space is free to be used as you please. I for instance have installed a towel rack where a radiator used to be.
Radiators, especially electric ones get very hot. If something, like a towel, were to be dropped on it there is a serious fire risk. Underfloor heating will never get so hot that it can burn someone or light something on fire. This makes it a much safer option compared to radiators.
Underfloor heating will eliminate all visible signs that there is a heating system installed. This allows for a minimalist design without any radiators or baseboard heater.
Better Air Quality
During winter months the indoor air tends to be very dry. This is because the house is constantly heated. Dry air can cause many uncomfortable symptoms such as:
- Eye irritation
- Sore throat
- Dry skin
Cheap non oil filled electric radiators dry the air more compared to underfloor heating. This is because the surface temperature of the radiator is much higher.
Dust also tends to collect on the radiator. For radiators to be effective they are not smooth. This increases the surface area and this allows for a small radiator to heat a larger space. (when compared to smooth radiators)
The shape of the radiator makes it impossible to clean the dust that is collected on it. This means that every time the radiator is heated up, the dust will be suspended in the air. This is especially noticeable when the radiators are turned on for the first time in the fall. This dust can cause breathing issues for people with asthma and other respiratory problems.
It is Easier To Clean The Bathroom
Since the walls of the bathroom are clear, overall cleaning of the bathroom is much easier. When radiators are installed, it is impossible to clean behind them. As we discussed earlier a lot of dust tends to collect on radiators over time.
With nothing in the way it is even possible to rinse the walls with water. This is something that can’t be done when a electric radiator is installed. For obvious reasons 🙂
Even Temperature And no Cold Spots
Underfloor heating will ensure that the temperature is even across the whole room. There will be no cold corners. As discussed before this can help prevent the growth of mold and mildew, but also it makes the room a much nicer place to be in.
Can Be Powered By Solar Power
If your house has a wet system it is possible to install a solar collector to help with the heating. A evacuated tube solar collector paired with a heat pump and underfloor heating will make for a extremely efficient heating solution.
The solar collector will preheat the water before it is pumped to the heat pump. Pair this with a low operating temperature of underfloor heating and you will have one of the most efficient heating system available today.
Keep in mind that the evacuated tubes will not melt snow since the warm water inside the tubes is insulated very well by the vacuum.
Before Installing Underfloor Heating In a Bathroom
If converting from radiators or forced air to underfloor heating, there are a couple of things that must be kept in mind to make the system as efficient and comfortable as possible.
Floor Insulation Is Very Important
Insulation is by far the most important thing when it comes to a efficient underfloor heating system. Unfortunately during remodels it is often not possible to add much insulation since this will raise the floor and it will be higher than other rooms.
However, even a thin sheet of highly efficient insulating material will make a big difference. A thin sheet of XPS insulation will make it much easier for the floor to be heated up as less heat is transferred down into the construction.
Do not install underfloor heating on top of a uninsulated floor. In the house I grew up the bathroom floor was not insulated and we installed wet underfloor heating on top. We were never able to heat up the floor. The uninsulated concrete slab absorbed all of the heat and the system was completely useless.
If possible try to figure out a solution where you can add at least 2″ XPS insulation under the heating elements. Unless the floor underneath is already very well insulated it will make a massive difference.
Consider The Added Height
The added height will be negligible when installing electric underfloor heating. The heating elements are only 1/8 ” thick and will be hidden in the tile adhesive. If you are going to re-tile just to add underfloor heating then the total height added will be about 3/4 ” or 20 mm
It’s a different story with wet underfloor heating. If you are not careful and choose a wrong type of system it could easily raise the floor by a couple of inches. This is why it is important to choose a low profile system. They use 1/2″ pipes and will raise the floor minimally.
It is best to place the thermostat high so children cannot reach it. When it comes to underfloor heating it is best to keep it warm all the time. If kids play with the thermostat and turn it off, it will take a couple of hours until the floor is heated up again. Not only will this be annoying, it will also waste energy.
Smart thermostats allow you to control the underfloor heating directly from your smartphone. While this is not essential, it is very comfortable to be able to set the schedule directly from the phone.
Some smart thermostats require a smart home hub in order for them to work. Others can work on their own.
There is a myriad of smart thermostats on the market. While they work great, they rely heavily on software updates and smartphone apps. A thermostat is usually something that will last for 10-20 years.
A smart thermostat of today will be likely very outdated in 10 years. If the manufacturer does not offer support for new phones, it can become useless. That is of course if the manufacturer is still in business after 10 years.
Without support to new devices, it becomes a standard thermostat that must be controlled manually. The problem is that some of them can not be set up fully from the device itself. The initial setup requires a smartphone.
This is why I tend to stay away from “smart” things that I expect to last for 10 years or more.
If you are set on a smart thermostat, look for one that can be controlled and set up from the device itself and not only from the hub or smartphone app. This way you can be sure that the thermostat is still usable even if the manufacturer stops developing software for new phones.
Emerson Sensi (amazon link) is one option. It looks more like a traditional thermostat, and works as a standalone unit, but can also be connected to most smart home hubs.
Wire to a GFCI
A ground fault circuit interrupter (GFCI) will protect the circuit from any voltage leaks. It is required by building code to wire bathroom underfloor heating to a GFCI. It will cut the power as soon as there is any voltage leak. This will protect anyone walking on the floor.
Related article: Do Bathroom Fans Require GFCI
The GFCI can be located at the distribution panel, or in the bathroom where the underfloor heating is connected. Some underfloor heating kits come with a GFCI so be sure to check this before you buy to avoid buying two.
For most consumer products manufacturers offer a 1-3 year warranty. Luckily this is not the case with underfloor heating systems.
Since the heating cable will be buried under tiles and will not be easily replaceable look for a kit with at least a 20-year warranty. Heatwave (amazon link) is one of the few companies that offer 20-year warranty.
Read the fine print and see if the warranty covers only the product itself, or labor to replace it as well. This can end up saving you thousands.